diff --git a/asynciterator.ts b/asynciterator.ts
index 3ec2ab6..7bb32c9 100644
--- a/asynciterator.ts
+++ b/asynciterator.ts
@@ -98,19 +98,12 @@ export class AsyncIterator<T> extends EventEmitter {
     @returns {boolean} Whether the state was changed
     @emits module:asynciterator.AsyncIterator.end
   */
-  protected _changeState(newState: number, eventAsync = false) {
+  protected _changeState(newState: number) {
     // Validate the state change
     const valid = newState > this._state && this._state < ENDED;
-    if (valid) {
+    if (valid)
       this._state = newState;
-      // Emit the `end` event when changing to ENDED
-      if (newState === ENDED) {
-        if (!eventAsync)
-          this.emit('end');
-        else
-          taskScheduler(() => this.emit('end'));
-      }
-    }
+
     return valid;
   }
 
@@ -128,6 +121,8 @@ export class AsyncIterator<T> extends EventEmitter {
     @returns {object?} The next item, or `null` if none is available
   */
   read(): T | null {
+    if (this._state === CLOSED)
+      this._end();
     return null;
   }
 
@@ -170,8 +165,12 @@ export class AsyncIterator<T> extends EventEmitter {
     @emits module:asynciterator.AsyncIterator.end
   */
   close() {
-    if (this._changeState(CLOSED))
-      this._endAsync();
+    if (this._changeState(CLOSED)) {
+      if (this.readable)
+        emitData.call(this);
+      else
+        this.readable = true;
+    }
   }
 
   /**
@@ -216,6 +215,8 @@ export class AsyncIterator<T> extends EventEmitter {
   */
   protected _end(destroy = false) {
     if (this._changeState(destroy ? DESTROYED : ENDED)) {
+      if (!destroy)
+        this.emit('end');
       this._readable = false;
       this.removeAllListeners('readable');
       this.removeAllListeners('data');
@@ -223,14 +224,6 @@ export class AsyncIterator<T> extends EventEmitter {
     }
   }
 
-  /**
-    Asynchronously calls `_end`.
-    @protected
-  */
-  protected _endAsync() {
-    taskScheduler(() => this._end());
-  }
-
   /**
     The `end` event is emitted after the last item of the iterator has been read.
     @event module:asynciterator.end
@@ -432,7 +425,7 @@ export class AsyncIterator<T> extends EventEmitter {
     After this operation, only read the returned iterator instead of the current one.
     @param {object|Function} [options] Settings of the iterator, or the transformation function
     @param {integer} [options.maxbufferSize=4] The maximum number of items to keep in the buffer
-    @param {boolean} [options.autoStart=true] Whether buffering starts directly after construction
+    @param {boolean} [options.preBuffer=true] Whether buffering starts directly after construction
     @param {integer} [options.offset] The number of items to skip
     @param {integer} [options.limit] The maximum number of items
     @param {Function} [options.filter] A function to synchronously filter items from the source
@@ -583,16 +576,16 @@ export class EmptyIterator<T> extends AsyncIterator<T> {
   /** Creates a new `EmptyIterator`. */
   constructor() {
     super();
-    this._changeState(ENDED, true);
+    this.close();
   }
 }
 
 
 /**
   An iterator that emits a single item.
-  @extends module:asynciterator.AsyncIterator
+  @extends module:asynciterator.EmptyIterator
 */
-export class SingletonIterator<T> extends AsyncIterator<T> {
+export class SingletonIterator<T> extends EmptyIterator<T> {
   private _item: T | null;
 
   /**
@@ -602,17 +595,14 @@ export class SingletonIterator<T> extends AsyncIterator<T> {
   constructor(item: T) {
     super();
     this._item = item;
-    if (item === null)
-      this.close();
-    else
-      this.readable = true;
   }
 
   /* Reads the item from the iterator. */
   read() {
     const item = this._item;
     this._item = null;
-    this.close();
+    if (item === null)
+      this._end();
     return item;
   }
 
@@ -625,43 +615,33 @@ export class SingletonIterator<T> extends AsyncIterator<T> {
 
 /**
   An iterator that emits the items of a given array.
-  @extends module:asynciterator.AsyncIterator
+  @extends module:asynciterator.EmptyIterator
 */
-export class ArrayIterator<T> extends AsyncIterator<T> {
+export class ArrayIterator<T> extends EmptyIterator<T> {
   private _buffer?: T[];
-  protected _sourceStarted: boolean;
 
   /**
     Creates a new `ArrayIterator`.
     @param {Array} items The items that will be emitted.
   */
-  constructor(items?: Iterable<T>, { autoStart = true } = {}) {
+  constructor(items: Iterable<T>) {
     super();
-    const buffer = items ? [...items] : [];
-    this._sourceStarted = autoStart !== false;
-    if (this._sourceStarted && buffer.length === 0)
-      this.close();
-    else
+    const buffer = [...items];
+    if (buffer.length !== 0)
       this._buffer = buffer;
-    this.readable = true;
   }
 
   /* Reads an item from the iterator. */
   read() {
-    if (!this._sourceStarted)
-      this._sourceStarted = true;
-
-    let item = null;
-    const buffer = this._buffer;
-    if (buffer) {
-      if (buffer.length !== 0)
-        item = buffer.shift() as T;
-      if (buffer.length === 0) {
-        delete this._buffer;
-        this.close();
-      }
+    const { _buffer } = this;
+    if (!_buffer) {
+      this._end();
+      return null;
     }
-    return item;
+    if (_buffer.length === 1)
+      delete this._buffer;
+
+    return _buffer.shift() as T;
   }
 
   /* Generates details for a textual representation of the iterator. */
@@ -725,8 +705,10 @@ export class IntegerIterator extends AsyncIterator<number> {
 
   /* Reads an item from the iterator. */
   read() {
-    if (this.closed)
+    if (this.closed) {
+      this._end();
       return null;
+    }
     const current = this._next, step = this._step, last = this._last,
           next = this._next += step;
     if (step >= 0 ? next > last : next < last)
@@ -758,13 +740,13 @@ export class BufferedIterator<T> extends AsyncIterator<T> {
     Creates a new `BufferedIterator`.
     @param {object} [options] Settings of the iterator
     @param {integer} [options.maxBufferSize=4] The number of items to preload in the internal buffer
-    @param {boolean} [options.autoStart=true] Whether buffering starts directly after construction
+    @param {boolean} [options.preBuffer=true] Whether buffering starts directly after construction
   */
-  constructor({ maxBufferSize = 4, autoStart = true } = {}) {
+  constructor({ maxBufferSize = 4, preBuffer = true } = {}) {
     super(INIT);
     this.maxBufferSize = maxBufferSize;
-    taskScheduler(() => this._init(autoStart));
-    this._sourceStarted = autoStart !== false;
+    taskScheduler(() => this._init(preBuffer));
+    this._sourceStarted = preBuffer !== false;
   }
 
   /**
@@ -796,9 +778,9 @@ export class BufferedIterator<T> extends AsyncIterator<T> {
     Initializing the iterator by calling {@link BufferedIterator#_begin}
     and changing state from INIT to OPEN.
     @protected
-    @param {boolean} autoStart Whether reading of items should immediately start after OPEN.
+    @param {boolean} preBuffer Whether reading of items should immediately start after OPEN.
   */
-  protected _init(autoStart: boolean) {
+  protected _init(preBuffer: boolean) {
     // Perform initialization tasks
     let doneCalled = false;
     this._reading = true;
@@ -809,7 +791,7 @@ export class BufferedIterator<T> extends AsyncIterator<T> {
       // Open the iterator and start buffering
       this._reading = false;
       this._changeState(OPEN);
-      if (autoStart)
+      if (preBuffer)
         this._fillBufferAsync();
       // If reading should not start automatically, the iterator doesn't become readable.
       // Therefore, mark the iterator as (potentially) readable so consumers know it might be read.
@@ -850,6 +832,8 @@ export class BufferedIterator<T> extends AsyncIterator<T> {
       item = buffer.shift() as T;
     }
     else {
+      if (this._state === CLOSED)
+        this._end();
       item = null;
       this.readable = false;
     }
@@ -859,9 +843,6 @@ export class BufferedIterator<T> extends AsyncIterator<T> {
       // If the iterator is not closed and thus may still generate new items, fill the buffer
       if (!this.closed)
         this._fillBufferAsync();
-      // No new items will be generated, so if none are buffered, the iterator ends here
-      else if (!buffer.length)
-        this._endAsync();
     }
 
     return item;
@@ -976,17 +957,15 @@ export class BufferedIterator<T> extends AsyncIterator<T> {
     @emits module:asynciterator.AsyncIterator.end
   */
   protected _completeClose() {
-    if (this._changeState(CLOSED)) {
+    if (this._state < CLOSED) {
       // Write possible terminating items
       this._reading = true;
       this._flush(() => {
         if (!this._reading)
           throw new Error('done callback called multiple times');
         this._reading = false;
-        // If no items are left, end the iterator
-        // Otherwise, `read` becomes responsible for ending the iterator
-        if (!this._buffer.length)
-          this._endAsync();
+        // If no items are left, close the iterator
+        AsyncIterator.prototype.close.call(this);
       });
     }
   }
@@ -1035,7 +1014,7 @@ export class TransformIterator<S, D = S> extends BufferedIterator<D> {
     @param {module:asynciterator.AsyncIterator|Readable} [source] The source this iterator generates items from
     @param {object} [options] Settings of the iterator
     @param {integer} [options.maxBufferSize=4] The maximum number of items to keep in the buffer
-    @param {boolean} [options.autoStart=true] Whether buffering starts directly after construction
+    @param {boolean} [options.preBuffer=true] Whether buffering starts directly after construction
     @param {boolean} [options.optional=false] If transforming is optional, the original item is pushed when its transformation yields no items
     @param {boolean} [options.destroySource=true] Whether the source should be destroyed when this transformed iterator is closed or destroyed
     @param {module:asynciterator.AsyncIterator} [options.source] The source this iterator generates items from
@@ -1233,7 +1212,7 @@ export class SimpleTransformIterator<S, D = S> extends TransformIterator<S, D> {
     @param {module:asynciterator.AsyncIterator|Readable} [source] The source this iterator generates items from
     @param {object|Function} [options] Settings of the iterator, or the transformation function
     @param {integer} [options.maxbufferSize=4] The maximum number of items to keep in the buffer
-    @param {boolean} [options.autoStart=true] Whether buffering starts directly after construction
+    @param {boolean} [options.preBuffer=true] Whether buffering starts directly after construction
     @param {module:asynciterator.AsyncIterator} [options.source] The source this iterator generates items from
     @param {integer} [options.offset] The number of items to skip
     @param {integer} [options.limit] The maximum number of items
@@ -1375,7 +1354,7 @@ export class MultiTransformIterator<S, D = S> extends TransformIterator<S, D> {
    @param {module:asynciterator.AsyncIterator|Readable} [source] The source this iterator generates items from
    @param {object|Function} [options] Settings of the iterator, or the transformation function
    @param {integer} [options.maxbufferSize=4] The maximum number of items to keep in the buffer
-   @param {boolean} [options.autoStart=true] Whether buffering starts directly after construction
+   @param {boolean} [options.preBuffer=true] Whether buffering starts directly after construction
    @param {module:asynciterator.AsyncIterator} [options.source] The source this iterator generates items from
    @param {integer} [options.offset] The number of items to skip
    @param {integer} [options.limit] The maximum number of items
@@ -1405,15 +1384,29 @@ export class MultiTransformIterator<S, D = S> extends TransformIterator<S, D> {
     // Remove transformers that have ended
     const transformerQueue = this._transformerQueue, optional = this._optional;
     let head, item;
-    while ((head = transformerQueue[0]) && head.transformer.done) {
+    while ((head = transformerQueue[0]) !== undefined) {
+      const { transformer } = head;
+      while (count > 0 && (item = transformer.read()) !== null) {
+        count--;
+        this._push(item);
+        // If a transformed item was pushed, no need to push the original anymore
+        if (optional && head.item !== null)
+          head.item = null;
+      }
+
+      // If the transformer is not done, end this read so it has time to load items
+      if (!transformer.done)
+        break;
+
       // If transforming is optional, push the original item if none was pushed
       if (optional && head.item !== null) {
+        if (count === 0)
+          break;
+
         count--;
         this._push(head.item as any as D);
       }
-      // Remove listeners from the transformer
       transformerQueue.shift();
-      const { transformer } = head;
       transformer.removeListener('end', destinationFillBuffer);
       transformer.removeListener('readable', destinationFillBuffer);
       transformer.removeListener('error', destinationEmitError);
@@ -1436,21 +1429,10 @@ export class MultiTransformIterator<S, D = S> extends TransformIterator<S, D> {
       transformerQueue.push({ transformer, item });
     }
 
-    // Try to read `count` items from the transformer
-    head = transformerQueue[0];
-    if (head) {
-      const { transformer } = head;
-      while (count-- > 0 && (item = transformer.read()) !== null) {
-        this._push(item);
-        // If a transformed item was pushed, no need to push the original anymore
-        if (optional)
-          head.item = null;
-      }
-    }
     // End the iterator if the source has ended
-    else if (source && source.done) {
+    if (transformerQueue.length === 0 && source && source.done)
       this.close();
-    }
+
     done();
   }
 
@@ -1488,13 +1470,13 @@ export class UnionIterator<T> extends BufferedIterator<T> {
   constructor(sources: AsyncIteratorOrArray<AsyncIterator<T>>,
               options: BufferedIteratorOptions = {}) {
     super(options);
-    const autoStart = options.autoStart !== false;
+    const preBuffer = options.preBuffer !== false;
 
     // Sources have been passed as an iterator
     if (isEventEmitter(sources)) {
       sources.on('error', error => this.emit('error', error));
       this._pending = { sources };
-      if (autoStart)
+      if (preBuffer)
         this._loadSources();
     }
     // Sources have been passed as a non-empty array
@@ -1503,7 +1485,7 @@ export class UnionIterator<T> extends BufferedIterator<T> {
         this._addSource(source as InternalSource<T>);
     }
     // Sources are an empty list
-    else if (autoStart) {
+    else if (preBuffer) {
       this.close();
     }
   }
@@ -1600,7 +1582,7 @@ export class ClonedIterator<T> extends TransformIterator<T> {
     @param {module:asynciterator.AsyncIterator|Readable} [source] The source this iterator copies items from
   */
   constructor(source: AsyncIterator<T>) {
-    super(source, { autoStart: false });
+    super(source, { preBuffer: false });
     this._reading = false;
   }
 
@@ -1626,7 +1608,7 @@ export class ClonedIterator<T> extends TransformIterator<T> {
       (source._destination = new HistoryReader<T>(source) as any);
 
     // Close this clone if history is empty and the source has ended
-    if (history.endsAt(0)) {
+    if (history.endsAt(0) || (source as any)._state === CLOSED) {
       this.close();
     }
     else {
@@ -1714,9 +1696,13 @@ export class ClonedIterator<T> extends TransformIterator<T> {
       else
         this.readable = false;
       // Close the iterator if we are at the end of the source
-      if (history.endsAt(this._readPosition))
+      if (history.endsAt(this._readPosition) || (source as any)._state === CLOSED)
         this.close();
     }
+
+    if (this._state === CLOSED && item === null)
+      this._end(false);
+
     return item;
   }
 
@@ -1885,7 +1871,7 @@ function isSourceExpression<T>(object: any): object is SourceExpression<T> {
 
 export interface BufferedIteratorOptions {
   maxBufferSize?: number;
-  autoStart?: boolean;
+  preBuffer?: boolean;
 }
 
 export interface TransformIteratorOptions<S> extends BufferedIteratorOptions {
diff --git a/package-lock.json b/package-lock.json
index 831df0f..b048a40 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -19,6 +19,7 @@
         "c8": "^7.2.0",
         "chai": "^4.2.0",
         "eslint": "^5.16.0",
+        "event-emitter-promisify": "^1.1.0",
         "husky": "^4.2.5",
         "jaguarjs-jsdoc": "^1.1.0",
         "jsdoc": "^3.5.5",
@@ -2002,6 +2003,12 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/event-emitter-promisify": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/event-emitter-promisify/-/event-emitter-promisify-1.1.0.tgz",
+      "integrity": "sha512-uyHG8gjwYGDlKoo0Txtx/u1HI1ubj0FK0rVqI4O0s1EymQm4iAEMbrS5B+XFlSaS8SZ3xzoKX+YHRZk8Nk/bXg==",
+      "dev": true
+    },
     "node_modules/expand-brackets": {
       "version": "2.1.4",
       "resolved": "https://registry.npmjs.org/expand-brackets/-/expand-brackets-2.1.4.tgz",
@@ -7622,6 +7629,12 @@
       "integrity": "sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g==",
       "dev": true
     },
+    "event-emitter-promisify": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/event-emitter-promisify/-/event-emitter-promisify-1.1.0.tgz",
+      "integrity": "sha512-uyHG8gjwYGDlKoo0Txtx/u1HI1ubj0FK0rVqI4O0s1EymQm4iAEMbrS5B+XFlSaS8SZ3xzoKX+YHRZk8Nk/bXg==",
+      "dev": true
+    },
     "expand-brackets": {
       "version": "2.1.4",
       "resolved": "https://registry.npmjs.org/expand-brackets/-/expand-brackets-2.1.4.tgz",
diff --git a/package.json b/package.json
index 06ab110..ecf20a8 100644
--- a/package.json
+++ b/package.json
@@ -48,6 +48,7 @@
     "c8": "^7.2.0",
     "chai": "^4.2.0",
     "eslint": "^5.16.0",
+    "event-emitter-promisify": "^1.1.0",
     "husky": "^4.2.5",
     "jaguarjs-jsdoc": "^1.1.0",
     "jsdoc": "^3.5.5",
diff --git a/test/ArrayIterator-test.js b/test/ArrayIterator-test.js
index a7464aa..9300da5 100644
--- a/test/ArrayIterator-test.js
+++ b/test/ArrayIterator-test.js
@@ -5,12 +5,13 @@ import {
 } from '../dist/asynciterator.js';
 
 import { EventEmitter } from 'events';
+import { promisifyEventEmitter } from 'event-emitter-promisify';
 
 describe('ArrayIterator', () => {
   describe('The ArrayIterator function', () => {
     describe('the result when called with `new`', () => {
       let instance;
-      before(() => { instance = new ArrayIterator(); });
+      before(() => { instance = new ArrayIterator([]); });
 
       it('should be an ArrayIterator object', () => {
         instance.should.be.an.instanceof(ArrayIterator);
@@ -27,7 +28,7 @@ describe('ArrayIterator', () => {
 
     describe('the result when called through `fromArray`', () => {
       let instance;
-      before(() => { instance = fromArray(); });
+      before(() => { instance = fromArray([]); });
 
       it('should be an ArrayIterator object', () => {
         instance.should.be.an.instanceof(ArrayIterator);
@@ -46,7 +47,7 @@ describe('ArrayIterator', () => {
   describe('An ArrayIterator without arguments', () => {
     let iterator;
     before(() => {
-      iterator = new ArrayIterator();
+      iterator = new ArrayIterator([]);
       captureEvents(iterator, 'readable', 'end');
     });
 
@@ -54,8 +55,17 @@ describe('ArrayIterator', () => {
       iterator.toString().should.equal('[ArrayIterator (0)]');
     });
 
-    it('should not have emitted the `readable` event', () => {
-      iterator._eventCounts.readable.should.equal(0);
+    it('should have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('end', done);
+      iterator.on('data', () => { throw new Error('should not emit data'); });
     });
 
     it('should have emitted the `end` event', () => {
@@ -95,7 +105,16 @@ describe('ArrayIterator', () => {
     });
 
     it('should not have emitted the `readable` event', () => {
-      iterator._eventCounts.readable.should.equal(0);
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('data', () => { throw new Error('should not emit data'); });
+      iterator.on('end', done);
     });
 
     it('should have emitted the `end` event', () => {
@@ -127,10 +146,127 @@ describe('ArrayIterator', () => {
     });
   });
 
-  describe('An ArrayIterator with an empty array without autoStart', () => {
+  describe('An ArrayIterator with an empty array (no use of flow)', () => {
     let iterator;
     before(() => {
-      iterator = new ArrayIterator([], { autoStart: false });
+      iterator = new ArrayIterator([]);
+      captureEvents(iterator, 'readable', 'end');
+    });
+
+    it('should provide a readable `toString` representation', () => {
+      iterator.toString().should.equal('[ArrayIterator (0)]');
+    });
+
+    it('should not have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
+    it('should have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(1);
+    });
+
+    it('should have ended', () => {
+      iterator.ended.should.be.true;
+    });
+
+    it('should not have been destroyed', () => {
+      iterator.destroyed.should.be.false;
+    });
+
+    it('should be done', () => {
+      iterator.done.should.be.true;
+    });
+
+    it('should not be readable', () => {
+      iterator.readable.should.be.false;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+  });
+
+
+  describe('An ArrayIterator with an array [1] (no use of flow)', () => {
+    let iterator;
+    before(() => {
+      iterator = new ArrayIterator([1]);
+      captureEvents(iterator, 'readable', 'end');
+    });
+
+    it('should provide a readable `toString` representation', () => {
+      iterator.toString().should.equal('[ArrayIterator (1)]');
+    });
+
+    it('should not have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should return 1 when read is called', () => {
+      expect(iterator.read()).to.equal(1);
+    });
+
+    it('should not have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
+    it('should have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(1);
+    });
+
+    it('should have ended', () => {
+      iterator.ended.should.be.true;
+    });
+
+    it('should not have been destroyed', () => {
+      iterator.destroyed.should.be.false;
+    });
+
+    it('should be done', () => {
+      iterator.done.should.be.true;
+    });
+
+    it('should not be readable', () => {
+      iterator.readable.should.be.false;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+  });
+
+  describe('An ArrayIterator with an empty array', () => {
+    let iterator;
+    before(() => {
+      iterator = new ArrayIterator([]);
       captureEvents(iterator, 'readable', 'end');
     });
 
@@ -679,4 +815,56 @@ describe('ArrayIterator', () => {
       });
     });
   });
+
+  describe('A ArrayIterator with no elements should not emit until read from', () => {
+    it('awaiting undefined (with empty array)', async () => {
+      const iterator = new ArrayIterator([]);
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise (with empty array)', async () => {
+      const iterator = new ArrayIterator([]);
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting undefined (with one element)', async () => {
+      const iterator = new ArrayIterator([1]);
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise (with one element)', async () => {
+      const iterator = new ArrayIterator([1]);
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+  });
+
+  describe('An ArrayIterator with no elements should not emit until read from (fromArray constructor)', () => {
+    it('awaiting undefined (with empty array)', async () => {
+      const iterator = fromArray([]);
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise (with empty array)', async () => {
+      const iterator = fromArray([]);
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting undefined (with one element)', async () => {
+      const iterator = fromArray([1]);
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise (with one element)', async () => {
+      const iterator = fromArray([1]);
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+  });
 });
diff --git a/test/AsyncIterator-test.js b/test/AsyncIterator-test.js
index 37a74d6..58a470c 100644
--- a/test/AsyncIterator-test.js
+++ b/test/AsyncIterator-test.js
@@ -97,8 +97,8 @@ describe('AsyncIterator', () => {
     describe('after close has been called', () => {
       before(() => { iterator.close(); });
 
-      it('should not have emitted another `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(1);
+      it('should have emitted another `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(2);
       });
 
       it('should have emitted the `end` event', () => {
@@ -141,7 +141,7 @@ describe('AsyncIterator', () => {
       before(() => { iterator.destroy(); });
 
       it('should not have emitted another `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(1);
+        iterator._eventCounts.readable.should.equal(2);
       });
 
       it('should have emitted the `end` event', () => {
@@ -184,7 +184,7 @@ describe('AsyncIterator', () => {
       before(() => { iterator.close(); });
 
       it('should not have emitted another `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(1);
+        iterator._eventCounts.readable.should.equal(2);
       });
 
       it('should not have emitted the `end` event a second time', () => {
@@ -639,13 +639,27 @@ describe('AsyncIterator', () => {
       });
     });
 
-    describe('after the iterator is closed', () => {
+    describe('after the iterator is closed ', () => {
       before(() => {
         iterator.close();
       });
 
+      it('should have closed', () => {
+        iterator._state.should.equal(CLOSED);
+      });
+    });
+
+    describe('after the iterator is closed and then _end', () => {
+      before(() => {
+        iterator._end();
+      });
+
+      it('should have ended', () => {
+        iterator._state.should.equal(ENDED);
+      });
+
       it('should not have listeners for the `data` event', () => {
-        EventEmitter.listenerCount(iterator, 'readable').should.equal(0);
+        EventEmitter.listenerCount(iterator, 'data').should.equal(0);
       });
 
       it('should not be listening for the `readable` event', () => {
@@ -681,7 +695,7 @@ describe('AsyncIterator', () => {
       });
 
       it('should not have listeners for the `data` event', () => {
-        EventEmitter.listenerCount(iterator, 'readable').should.equal(0);
+        EventEmitter.listenerCount(iterator, 'data').should.equal(0);
       });
 
       it('should not be listening for the `readable` event', () => {
@@ -723,7 +737,7 @@ describe('AsyncIterator', () => {
       });
 
       it('should not have listeners for the `data` event', () => {
-        EventEmitter.listenerCount(iterator, 'readable').should.equal(0);
+        EventEmitter.listenerCount(iterator, 'data').should.equal(0);
       });
 
       it('should not be listening for the `readable` event', () => {
@@ -1092,7 +1106,7 @@ describe('AsyncIterator', () => {
       before(done => {
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => iterator.close() || null;
+        iterator.read = () => iterator._end() || null;
         iterator.toArray().then(array => {
           result = array;
           done();
@@ -1110,7 +1124,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 2 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 2 ? i : (iterator._end() || null);
         iterator.toArray().then(array => {
           result = array;
           done();
@@ -1147,7 +1161,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({}).then(array => {
           result = array;
           done();
@@ -1165,7 +1179,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray(null).then(array => {
           result = array;
           done();
@@ -1183,7 +1197,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({ limit: 0 }).then(array => {
           result = array;
           done();
@@ -1201,7 +1215,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({ limit: -3 }).then(array => {
           result = array;
           done();
@@ -1219,7 +1233,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({ limit: -0 }).then(array => {
           result = array;
           done();
@@ -1237,7 +1251,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({ limit: '3' }).then(array => {
           result = array;
           done();
@@ -1255,7 +1269,7 @@ describe('AsyncIterator', () => {
         i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({ limit: 3 }).then(array => {
           result = array;
           done();
@@ -1295,7 +1309,7 @@ describe('AsyncIterator', () => {
         let i = 0;
         iterator = new AsyncIterator();
         iterator.readable = true;
-        iterator.read = () => i++ < 5 ? i : (iterator.close() || null);
+        iterator.read = () => i++ < 5 ? i : (iterator._end() || null);
         iterator.toArray({ limit: 10 }).then(array => {
           result = array;
           done();
diff --git a/test/BufferedIterator-test.js b/test/BufferedIterator-test.js
index ce59d48..2b583e0 100644
--- a/test/BufferedIterator-test.js
+++ b/test/BufferedIterator-test.js
@@ -75,6 +75,23 @@ describe('BufferedIterator', () => {
         iterator.close();
       });
 
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -113,9 +130,9 @@ describe('BufferedIterator', () => {
       return captureEvents(iterator, 'readable', 'end');
     }
 
-    describe('without autoStart', () => {
+    describe('without preBuffer', () => {
       let iterator;
-      before(() => { iterator = createIterator({ autoStart: false }); });
+      before(() => { iterator = createIterator({ preBuffer: false }); });
 
       describe('before `read` has been called', () => {
         it('should have emitted the `readable` event', () => {
@@ -155,10 +172,24 @@ describe('BufferedIterator', () => {
           expect(item).to.be.null;
         });
 
-        it('should not have emitted the `readable` event anymore', () => {
-          iterator._eventCounts.readable.should.equal(1);
+        it('should have emitted the `readable` event', () => {
+          iterator._eventCounts.readable.should.equal(2);
+        });
+
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
         });
 
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -194,7 +225,7 @@ describe('BufferedIterator', () => {
         });
 
         it('should not have emitted the `readable` event anymore', () => {
-          iterator._eventCounts.readable.should.equal(1);
+          iterator._eventCounts.readable.should.equal(2);
         });
 
         it('should not have emitted another `end` event', () => {
@@ -223,13 +254,30 @@ describe('BufferedIterator', () => {
       });
     });
 
-    describe('with autoStart', () => {
+    describe('with preBuffer', () => {
       let iterator;
       before(() => { iterator = createIterator(); });
 
       describe('before `read` has been called', () => {
-        it('should not have emitted the `readable` event', () => {
-          iterator._eventCounts.readable.should.equal(0);
+        it('should have emitted the `readable` event', () => {
+          iterator._eventCounts.readable.should.equal(1);
+        });
+
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
         });
 
         it('should have emitted the `end` event', () => {
@@ -267,7 +315,7 @@ describe('BufferedIterator', () => {
         });
 
         it('should not have emitted the `readable` event', () => {
-          iterator._eventCounts.readable.should.equal(0);
+          iterator._eventCounts.readable.should.equal(1);
         });
 
         it('should not have emitted another `end` event', () => {
@@ -310,9 +358,9 @@ describe('BufferedIterator', () => {
       return captureEvents(iterator, 'readable', 'end');
     }
 
-    describe('without autoStart', () => {
+    describe('without preBuffer', () => {
       let iterator;
-      before(() => { iterator = createIterator({ autoStart: false }); });
+      before(() => { iterator = createIterator({ preBuffer: false }); });
 
       describe('before `read` has been called', () => {
         it('should have emitted the `readable` event', () => {
@@ -353,7 +401,24 @@ describe('BufferedIterator', () => {
         });
 
         it('should not have emitted another `readable` event', () => {
-          iterator._eventCounts.readable.should.equal(1);
+          iterator._eventCounts.readable.should.equal(2);
+        });
+
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
         });
 
         it('should have emitted the `end` event', () => {
@@ -391,7 +456,7 @@ describe('BufferedIterator', () => {
         });
 
         it('should not have emitted another `readable` event', () => {
-          iterator._eventCounts.readable.should.equal(1);
+          iterator._eventCounts.readable.should.equal(2);
         });
 
         it('should not have emitted another `end` event', () => {
@@ -420,13 +485,31 @@ describe('BufferedIterator', () => {
       });
     });
 
-    describe('with autoStart', () => {
+    describe('with preBuffer', () => {
       let iterator;
       before(() => { iterator = createIterator(); });
 
       describe('before `read` has been called', () => {
         it('should not have emitted the `readable` event', () => {
-          iterator._eventCounts.readable.should.equal(0);
+          iterator._eventCounts.readable.should.equal(1);
+        });
+
+
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
         });
 
         it('should have emitted the `end` event', () => {
@@ -464,7 +547,7 @@ describe('BufferedIterator', () => {
         });
 
         it('should not have emitted the `readable` event', () => {
-          iterator._eventCounts.readable.should.equal(0);
+          iterator._eventCounts.readable.should.equal(1);
         });
 
         it('should not have emitted another `end` event', () => {
@@ -535,7 +618,24 @@ describe('BufferedIterator', () => {
       before(() => { iterator.close(); });
 
       it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
+      it('should not be readable', () => {
+        iterator.readable.should.be.false;
       });
 
       it('should have emitted the `end` event', () => {
@@ -563,7 +663,7 @@ describe('BufferedIterator', () => {
   describe('A BufferedIterator that is being closed while reading is in progress', () => {
     let iterator, _readDone;
     function createIterator() {
-      iterator = new BufferedIterator({ autoStart: false, maxBufferSize: 1 });
+      iterator = new BufferedIterator({ preBuffer: false, maxBufferSize: 1 });
       iterator._read = (count, done) => { _readDone = done; };
       sinon.spy(iterator, '_read');
       captureEvents(iterator, 'readable', 'end');
@@ -606,6 +706,24 @@ describe('BufferedIterator', () => {
           // because the iterator closes before an asynchronous _read can take place
         });
 
+
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
+        });
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -664,6 +782,23 @@ describe('BufferedIterator', () => {
           scheduleTask(() => { iterator.close(); });
         });
 
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
+        });
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -839,6 +974,24 @@ describe('BufferedIterator', () => {
           iterator._eventCounts.readable.should.equal(2);
         });
 
+
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
+        });
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -1014,6 +1167,23 @@ describe('BufferedIterator', () => {
           iterator._eventCounts.readable.should.equal(2);
         });
 
+        it('should not emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should be readable', () => {
+          iterator.readable.should.be.true;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
+        it('should not be readable', () => {
+          iterator.readable.should.be.false;
+        });
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -1057,9 +1227,9 @@ describe('BufferedIterator', () => {
       return captureEvents(iterator, 'readable', 'end');
     }
 
-    describe('without autoStart', () => {
+    describe('without preBuffer', () => {
       let iterator;
-      before(() => { iterator = createIterator({ autoStart: false }); });
+      before(() => { iterator = createIterator({ preBuffer: false }); });
 
       it('should provide a readable `toString` representation', () => {
         iterator.toString().should.equal('[BufferedIterator {buffer: 0}]');
@@ -1145,6 +1315,23 @@ describe('BufferedIterator', () => {
           iterator._eventCounts.readable.should.equal(2);
         });
 
+        it('should have emitted the `readable` event', () => {
+          iterator._eventCounts.readable.should.equal(2);
+        });
+
+        it('should not have emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should not have ended', () => {
+          iterator.ended.should.be.false;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -1209,7 +1396,7 @@ describe('BufferedIterator', () => {
       });
     });
 
-    describe('with autoStart', () => {
+    describe('with preBuffer', () => {
       let iterator;
       before(() => { iterator = createIterator(); });
 
@@ -1260,6 +1447,23 @@ describe('BufferedIterator', () => {
           iterator._eventCounts.readable.should.equal(1);
         });
 
+        it('should have emitted the `readable` event', () => {
+          iterator._eventCounts.readable.should.equal(1);
+        });
+
+        it('should not have emitted the `end` event', () => {
+          iterator._eventCounts.end.should.equal(0);
+        });
+
+        it('should not have ended', () => {
+          iterator.ended.should.be.false;
+        });
+
+        it('emit end once data is subscribed', done => {
+          iterator.on('end', done);
+          iterator.on('data', () => { throw new Error('should not emit data'); });
+        });
+
         it('should have emitted the `end` event', () => {
           iterator._eventCounts.end.should.equal(1);
         });
@@ -1302,7 +1506,7 @@ describe('BufferedIterator', () => {
       return captureEvents(iterator, 'readable', 'end');
     }
 
-    describe('with autoStart enabled', () => {
+    describe('with preBuffer enabled', () => {
       let iterator;
       before(() => { iterator = createIterator(); });
 
@@ -1406,7 +1610,7 @@ describe('BufferedIterator', () => {
   describe('A BufferedIterator with `_read` that calls `done` multiple times', () => {
     let iterator, readDone;
     before(done => {
-      iterator = new BufferedIterator({ autoStart: false });
+      iterator = new BufferedIterator({ preBuffer: false });
       iterator._read = (count, callback) => { readDone = callback; };
       scheduleTask(() => { iterator.read(); done(); });
     });
@@ -1546,6 +1750,23 @@ describe('BufferedIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -1727,6 +1948,19 @@ describe('BufferedIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -1785,7 +2019,8 @@ describe('BufferedIterator', () => {
       expect(iterator.read()).to.equal('a');
     });
 
-    it('should return null on subsequent reads', () => {
+    it('should return null on subsequent reads (1)', () => {
+      expect(iterator.read()).to.be.null;
       expect(iterator.read()).to.be.null;
     });
 
@@ -1909,6 +2144,19 @@ describe('BufferedIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -2032,6 +2280,23 @@ describe('BufferedIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
diff --git a/test/ClonedIterator-test.js b/test/ClonedIterator-test.js
index 8b97ba4..3d32c37 100644
--- a/test/ClonedIterator-test.js
+++ b/test/ClonedIterator-test.js
@@ -87,8 +87,17 @@ describe('ClonedIterator', () => {
         expect(clone.source).to.be.undefined;
       });
 
-      it('should not have emitted the `readable` event', () => {
-        clone._eventCounts.readable.should.equal(0);
+      it('should have emitted the `readable` event', () => {
+        clone._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        clone._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        clone.on('end', done);
+        clone.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
@@ -133,8 +142,17 @@ describe('ClonedIterator', () => {
         getClone().toString().should.equal('[ClonedIterator {source: [EmptyIterator]}]');
       });
 
-      it('should not have emitted the `readable` event', () => {
-        getClone()._eventCounts.readable.should.equal(0);
+      it('should have emitted the `readable` event', () => {
+        getClone()._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        getClone()._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        getClone().on('end', done);
+        getClone().on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
@@ -145,11 +163,19 @@ describe('ClonedIterator', () => {
         getClone().ended.should.be.true;
       });
 
+      it('should not have been destroyed', () => {
+        getClone().destroyed.should.be.false;
+      });
+
+      it('should be done', () => {
+        getClone().done.should.be.true;
+      });
+
       it('should not be readable', () => {
         getClone().readable.should.be.false;
       });
 
-      it('should return null on read', () => {
+      it('should return null when read is called', () => {
         expect(getClone().read()).to.be.null;
       });
     });
@@ -226,6 +252,16 @@ describe('ClonedIterator', () => {
           getClone()._eventCounts.readable.should.equal(1);
         });
 
+
+        it('should not have emitted the `end` event', () => {
+          getClone()._eventCounts.end.should.equal(0);
+        });
+
+        it('emit end once data is subscribed', done => {
+          getClone().on('end', done);
+          getClone().on('data', () => { throw new Error('should not emit data'); });
+        });
+
         it('should have emitted the `end` event', () => {
           getClone()._eventCounts.end.should.equal(1);
         });
@@ -234,11 +270,19 @@ describe('ClonedIterator', () => {
           getClone().ended.should.be.true;
         });
 
+        it('should not have been destroyed', () => {
+          getClone().destroyed.should.be.false;
+        });
+
+        it('should be done', () => {
+          getClone().done.should.be.true;
+        });
+
         it('should not be readable', () => {
           getClone().readable.should.be.false;
         });
 
-        it('should return null on read', () => {
+        it('should return null when read is called', () => {
           expect(getClone().read()).to.be.null;
         });
       });
@@ -301,6 +345,16 @@ describe('ClonedIterator', () => {
           getClone()._eventCounts.readable.should.equal(1);
         });
 
+
+        it('should not have emitted the `end` event', () => {
+          getClone()._eventCounts.end.should.equal(0);
+        });
+
+        it('emit end once data is subscribed', done => {
+          getClone().on('end', done);
+          getClone().on('data', () => { throw new Error('should not emit data'); });
+        });
+
         it('should have emitted the `end` event', () => {
           getClone()._eventCounts.end.should.equal(1);
         });
@@ -309,11 +363,19 @@ describe('ClonedIterator', () => {
           getClone().ended.should.be.true;
         });
 
+        it('should not have been destroyed', () => {
+          getClone().destroyed.should.be.false;
+        });
+
+        it('should be done', () => {
+          getClone().done.should.be.true;
+        });
+
         it('should not be readable', () => {
           getClone().readable.should.be.false;
         });
 
-        it('should return null on read', () => {
+        it('should return null when read is called', () => {
           expect(getClone().read()).to.be.null;
         });
       });
@@ -402,6 +464,16 @@ describe('ClonedIterator', () => {
           getClone()._eventCounts.readable.should.equal(1);
         });
 
+
+        it('should not have emitted the `end` event', () => {
+          getClone()._eventCounts.end.should.equal(0);
+        });
+
+        it('emit end once data is subscribed', done => {
+          getClone().on('end', done);
+          getClone().on('data', () => { throw new Error('should not emit data'); });
+        });
+
         it('should have emitted the `end` event', () => {
           getClone()._eventCounts.end.should.equal(1);
         });
@@ -410,11 +482,19 @@ describe('ClonedIterator', () => {
           getClone().ended.should.be.true;
         });
 
+        it('should not have been destroyed', () => {
+          getClone().destroyed.should.be.false;
+        });
+
+        it('should be done', () => {
+          getClone().done.should.be.true;
+        });
+
         it('should not be readable', () => {
           getClone().readable.should.be.false;
         });
 
-        it('should return null on read', () => {
+        it('should return null when read is called', () => {
           expect(getClone().read()).to.be.null;
         });
       });
@@ -763,6 +843,7 @@ describe('ClonedIterator', () => {
           iterator.removeListener('error', noop);
           done();
         });
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should not leave any error handlers attached', () => {
diff --git a/test/EmptyIterator-test.js b/test/EmptyIterator-test.js
index caf21ab..064c085 100644
--- a/test/EmptyIterator-test.js
+++ b/test/EmptyIterator-test.js
@@ -5,6 +5,7 @@ import {
 } from '../dist/asynciterator.js';
 
 import { EventEmitter } from 'events';
+import { promisifyEventEmitter } from 'event-emitter-promisify';
 
 describe('EmptyIterator', () => {
   describe('The EmptyIterator function', () => {
@@ -54,8 +55,17 @@ describe('EmptyIterator', () => {
       iterator.toString().should.equal('[EmptyIterator]');
     });
 
-    it('should not have emitted the `readable` event', () => {
-      iterator._eventCounts.readable.should.equal(0);
+    it('should have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('end', done);
+      iterator.on('data', () => { throw new Error('should not emit data'); });
     });
 
     it('should have emitted the `end` event', () => {
@@ -74,4 +84,23 @@ describe('EmptyIterator', () => {
       expect(iterator.read()).to.be.null;
     });
   });
+
+  describe('An EmptyIterator should not emit until read from', () => {
+    it('no awaiting', async () => {
+      const iterator = new EmptyIterator();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting undefined', async () => {
+      const iterator = new EmptyIterator();
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise', async () => {
+      const iterator = new EmptyIterator();
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+  });
 });
diff --git a/test/IntegerIterator-test.js b/test/IntegerIterator-test.js
index 961805d..1567631 100644
--- a/test/IntegerIterator-test.js
+++ b/test/IntegerIterator-test.js
@@ -5,6 +5,7 @@ import {
 } from '../dist/asynciterator.js';
 
 import { EventEmitter } from 'events';
+import { promisifyEventEmitter } from 'event-emitter-promisify';
 
 describe('IntegerIterator', () => {
   describe('The IntegerIterator function', () => {
@@ -171,6 +172,20 @@ describe('IntegerIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -258,6 +273,19 @@ describe('IntegerIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -289,7 +317,20 @@ describe('IntegerIterator', () => {
 
     describe('before reading', () => {
       it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
@@ -322,8 +363,21 @@ describe('IntegerIterator', () => {
     });
 
     describe('before reading', () => {
-      it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
@@ -357,7 +411,20 @@ describe('IntegerIterator', () => {
 
     describe('before reading', () => {
       it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
@@ -390,8 +457,17 @@ describe('IntegerIterator', () => {
     });
 
     describe('before reading', () => {
-      it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
@@ -437,4 +513,42 @@ describe('IntegerIterator', () => {
       });
     });
   });
+
+  describe('An range iterator with no elements should not emit until read from (range constructor)', () => {
+    it('no awaiting', async () => {
+      const iterator = range(0, 0);
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting undefined', async () => {
+      const iterator = range(0, 0);
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise', async () => {
+      const iterator = range(0, 0);
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+  });
+
+  describe('An IntegerIterator with no elements should not emit until read from', () => {
+    it('no awaiting', async () => {
+      const iterator = new IntegerIterator({ start: 0, end: 0, step: 1 });
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting undefined', async () => {
+      const iterator = new IntegerIterator({ start: 0, end: 0, step: 1 });
+      await undefined;
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+
+    it('awaiting promise', async () => {
+      const iterator = new IntegerIterator({ start: 0, end: 0, step: 1 });
+      await Promise.resolve();
+      await expect(await promisifyEventEmitter(iterator.on('data', () => { /* */ }))).to.be.undefined;
+    });
+  });
 });
diff --git a/test/MultiTransformIterator-test.js b/test/MultiTransformIterator-test.js
index fc0c26b..9893d5a 100644
--- a/test/MultiTransformIterator-test.js
+++ b/test/MultiTransformIterator-test.js
@@ -10,6 +10,7 @@ import {
 } from '../dist/asynciterator.js';
 
 import { EventEmitter } from 'events';
+import { expect } from 'chai';
 
 describe('MultiTransformIterator', () => {
   describe('The MultiTransformIterator function', () => {
@@ -39,6 +40,26 @@ describe('MultiTransformIterator', () => {
     });
   });
 
+  describe('A MultiTransformIterator without options', () => {
+    let iterator, source;
+    before(() => {
+      source = new ArrayIterator(['a', 'b', 'c', 'd', 'e', 'f']);
+      iterator = new MultiTransformIterator(source, { preBuffer: false });
+    });
+
+    describe('when reading items', () => {
+      const items = [];
+      before(done => {
+        iterator.on('data', item => { items.push(item); });
+        iterator.on('end', done);
+      });
+
+      it('should return items as they are', () => {
+        items.should.deep.equal(['a', 'b', 'c', 'd', 'e', 'f']);
+      });
+    });
+  });
+
   describe('A MultiTransformIterator without options', () => {
     let iterator, source;
     before(() => {
@@ -59,11 +80,24 @@ describe('MultiTransformIterator', () => {
     });
   });
 
+  describe('A MultiTransformIterator with an ended AsyncIterator Source', () => {
+    let iterator, source;
+    before(() => {
+      source = new AsyncIterator();
+      iterator = new MultiTransformIterator(source);
+      source._end();
+    });
+
+    it('should be closed', () => {
+      expect(iterator.closed).to.be.true;
+    });
+  });
+
   describe('A MultiTransformIterator with transformers that emit 0 items', () => {
     let iterator, source;
     before(() => {
       source = new ArrayIterator(['a', 'b', 'c', 'd', 'e', 'f']);
-      iterator = new MultiTransformIterator(source, { autoStart: false });
+      iterator = new MultiTransformIterator(source, { preBuffer: false });
       iterator._createTransformer = sinon.spy(() => new EmptyIterator());
     });
 
@@ -139,6 +173,34 @@ describe('MultiTransformIterator', () => {
     });
   });
 
+  describe('A MultiTransformIterator with transformers that synchronously emit 5 items', () => {
+    let iterator, source;
+    before(() => {
+      source = new ArrayIterator(['a', 'b', 'c', 'd', 'e', 'f']);
+      iterator = new MultiTransformIterator(source);
+      iterator._createTransformer = sinon.spy(item => new ArrayIterator([`${item}1`, `${item}2`, `${item}3`, `${item}4`, `${item}5`]));
+    });
+
+    describe('when reading items', () => {
+      const items = [];
+      before(done => {
+        iterator.on('data', item => { items.push(item); });
+        iterator.on('end', done);
+      });
+
+      it('should return the transformed items', () => {
+        items.should.deep.equal([
+          'a1', 'a2', 'a3', 'a4', 'a5',
+          'b1', 'b2', 'b3', 'b4', 'b5',
+          'c1', 'c2', 'c3', 'c4', 'c5',
+          'd1', 'd2', 'd3', 'd4', 'd5',
+          'e1', 'e2', 'e3', 'e4', 'e5',
+          'f1', 'f2', 'f3', 'f4', 'f5',
+        ]);
+      });
+    });
+  });
+
   describe('A MultiTransformIterator with transformers that asynchronously close', () => {
     let iterator, source;
     before(() => {
@@ -293,6 +355,35 @@ describe('MultiTransformIterator', () => {
     });
   });
 
+
+  describe('A MultiTransformIterator with optional set to true', () => {
+    let iterator, source;
+    before(() => {
+      source = new ArrayIterator([1, 2, 3, 4, 5, 6]);
+      iterator = new MultiTransformIterator(source, { optional: true });
+      iterator._createTransformer = sinon.spy(item => {
+        switch (item) {
+        case 1: return new ArrayIterator(['1', '2', '3', '4']);
+        case 2: return null;
+        default: return new SingletonIterator(`t${item}`);
+        }
+      });
+    });
+
+    describe('when reading items', () => {
+      const items = [];
+      before(done => {
+        iterator.on('data', item => { items.push(item); });
+        iterator.on('end', done);
+      });
+
+      it('should return the transformed items, and originals when the transformer is empty', () => {
+        items.should.deep.equal(['1', '2', '3', '4', 2, 't3', 't4', 't5', 't6']);
+      });
+    });
+  });
+
+
   describe('A MultiTransformIterator with transformers that error', () => {
     let iterator, source;
     before(() => {
diff --git a/test/SimpleTransformIterator-test.js b/test/SimpleTransformIterator-test.js
index e033b8e..cb975bd 100644
--- a/test/SimpleTransformIterator-test.js
+++ b/test/SimpleTransformIterator-test.js
@@ -330,6 +330,19 @@ describe('SimpleTransformIterator', () => {
         source.read.should.have.been.calledOnce;
       });
 
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -556,7 +569,7 @@ describe('SimpleTransformIterator', () => {
     before(() => {
       source = new IntegerIterator({ start: 1, end: 10 });
       sinon.spy(source, 'read');
-      iterator = new SimpleTransformIterator(source, { offset: Infinity, autoStart: false });
+      iterator = new SimpleTransformIterator(source, { offset: Infinity, preBuffer: false });
     });
 
     describe('when reading items', () => {
@@ -631,7 +644,7 @@ describe('SimpleTransformIterator', () => {
     before(() => {
       source = new IntegerIterator({ start: 1, end: 10 });
       sinon.spy(source, 'read');
-      iterator = new SimpleTransformIterator(source, { limit: 0, autoStart: false });
+      iterator = new SimpleTransformIterator(source, { limit: 0, preBuffer: false });
     });
 
     describe('when reading items', () => {
@@ -706,7 +719,7 @@ describe('SimpleTransformIterator', () => {
     before(() => {
       source = new IntegerIterator({ start: 1, end: 10 });
       sinon.spy(source, 'read');
-      iterator = new SimpleTransformIterator(source, { limit: -1, autoStart: false });
+      iterator = new SimpleTransformIterator(source, { limit: -1, preBuffer: false });
     });
 
     describe('when reading items', () => {
@@ -731,7 +744,7 @@ describe('SimpleTransformIterator', () => {
     before(() => {
       source = new IntegerIterator({ start: 1, end: 10 });
       sinon.spy(source, 'read');
-      iterator = new SimpleTransformIterator(source, { limit: -Infinity, autoStart: false });
+      iterator = new SimpleTransformIterator(source, { limit: -Infinity, preBuffer: false });
     });
 
     describe('when reading items', () => {
diff --git a/test/SingletonIterator-test.js b/test/SingletonIterator-test.js
index 177ab28..3116f00 100644
--- a/test/SingletonIterator-test.js
+++ b/test/SingletonIterator-test.js
@@ -54,16 +54,65 @@ describe('SingletonIterator', () => {
       iterator.toString().should.equal('[SingletonIterator]');
     });
 
-    it('should not have emitted the `readable` event', () => {
-      iterator._eventCounts.readable.should.equal(0);
+    it('should have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should be readable', () => {
+      iterator.readable.should.be.true;
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('end', done);
+      iterator.on('data', () => { throw new Error('should not emit data'); });
     });
 
     it('should have emitted the `end` event', () => {
       iterator._eventCounts.end.should.equal(1);
     });
 
-    it('should have ended', () => {
-      iterator.ended.should.be.true;
+    it('should not be readable', () => {
+      iterator.readable.should.be.false;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+  });
+
+  describe('An SingletonIterator without item', () => {
+    let iterator;
+    before(() => {
+      iterator = new SingletonIterator(null);
+      captureEvents(iterator, 'readable', 'end');
+    });
+
+    it('should provide a readable `toString` representation', () => {
+      iterator.toString().should.equal('[SingletonIterator]');
+    });
+
+    it('should have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should be readable', () => {
+      iterator.readable.should.be.true;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
+    it('should have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(1);
     });
 
     it('should not be readable', () => {
@@ -132,4 +181,64 @@ describe('SingletonIterator', () => {
       });
     });
   });
+
+
+  describe('An SingletonIterator with an item', () => {
+    let iterator, item;
+    before(() => {
+      iterator = new SingletonIterator(1);
+      captureEvents(iterator, 'readable', 'end');
+    });
+
+    describe('before calling read', () => {
+      it('should provide a readable `toString` representation', () => {
+        iterator.toString().should.equal('[SingletonIterator (1)]');
+      });
+
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('should be readable', () => {
+        iterator.readable.should.be.true;
+      });
+    });
+
+    describe('after calling read for the first time', () => {
+      before(() => { item = iterator.read(); });
+
+      it('should provide a readable `toString` representation', () => {
+        iterator.toString().should.equal('[SingletonIterator]');
+      });
+
+      it('should read the first item of the array', () => {
+        item.should.equal(1);
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
+      it('should have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(1);
+      });
+
+      it('should have ended', () => {
+        iterator.ended.should.be.true;
+      });
+
+      it('should not be readable', () => {
+        iterator.readable.should.be.false;
+      });
+    });
+  });
 });
diff --git a/test/TransformIterator-test.js b/test/TransformIterator-test.js
index e5d8116..030d958 100644
--- a/test/TransformIterator-test.js
+++ b/test/TransformIterator-test.js
@@ -155,10 +155,28 @@ describe('TransformIterator', () => {
         expect(iterator.source).to.be.undefined;
       });
 
-      it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
+      it('should have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(1);
+      });
+
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -183,16 +201,78 @@ describe('TransformIterator', () => {
       iterator = new TransformIterator(source = new EmptyIterator());
       captureEvents(iterator, 'readable', 'end');
       expect(source._events).to.not.contain.key('data');
-      expect(source._events).to.not.contain.key('readable');
-      expect(source._events).to.not.contain.key('end');
+      // expect(source._events).to.not.contain.key('end');
+    });
+
+    it('should expose the source in the `source` property', () => {
+      iterator.source.should.equal(source);
+    });
+
+    it('should have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should not have ended', () => {
+      iterator.ended.should.be.false;
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('end', done);
+      iterator.on('data', () => { throw new Error('should not emit data'); });
+    });
+
+    it('should have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(1);
+    });
+
+    it('should have ended', () => {
+      iterator.ended.should.be.true;
+    });
+
+    it('should not be readable', () => {
+      iterator.readable.should.be.false;
+    });
+
+    it('should return null when read is called', () => {
+      expect(iterator.read()).to.be.null;
+    });
+  });
+
+
+  describe('A TransformIterator initialized with a completed empty source', () => {
+    let iterator, source;
+    before(() => {
+      source = new EmptyIterator();
+      source.read();
+      iterator = new TransformIterator(source);
+      captureEvents(iterator, 'readable', 'end');
+      expect(source._events).to.not.contain.key('data');
+      // expect(source._events).to.not.contain.key('end');
     });
 
     it('should expose the source in the `source` property', () => {
       iterator.source.should.equal(source);
     });
 
-    it('should not have emitted the `readable` event', () => {
-      iterator._eventCounts.readable.should.equal(0);
+    it('should have emitted the `readable` event', () => {
+      iterator._eventCounts.readable.should.equal(1);
+    });
+
+    it('should not have emitted the `end` event', () => {
+      iterator._eventCounts.end.should.equal(0);
+    });
+
+    it('should not have ended', () => {
+      iterator.ended.should.be.false;
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('end', done);
+      iterator.on('data', () => { throw new Error('should not emit data'); });
     });
 
     it('should have emitted the `end` event', () => {
@@ -268,14 +348,29 @@ describe('TransformIterator', () => {
     describe('after the source ends', () => {
       before(() => { source.close(); });
 
-      it('should not have emitted the `readable` event', () => {
-        iterator._eventCounts.readable.should.equal(0);
+
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
 
+
       it('should have ended', () => {
         iterator.ended.should.be.true;
       });
@@ -290,6 +385,26 @@ describe('TransformIterator', () => {
     });
   });
 
+  describe('A TransformIterator without options', () => {
+    let iterator, source;
+    before(() => {
+      source = new ArrayIterator(['a', 'b', 'c', 'd', 'e', 'f']);
+      iterator = new TransformIterator(source, { preBuffer: false });
+    });
+
+    describe('when reading items', () => {
+      const items = [];
+      before(done => {
+        iterator.on('data', item => { items.push(item); });
+        iterator.on('end', done);
+      });
+
+      it('should return items as they are', () => {
+        items.should.deep.equal(['a', 'b', 'c', 'd', 'e', 'f']);
+      });
+    });
+  });
+
   describe('A TransformIterator with a one-item source', () => {
     let iterator, source;
     before(() => {
@@ -301,8 +416,8 @@ describe('TransformIterator', () => {
     });
 
     describe('before reading an item', () => {
-      it('should have called `read` on the source', () => {
-        source.read.should.have.been.calledOnce;
+      it('should have called `read` on the source once to read, once to end', () => {
+        source.read.should.have.been.calledTwice;
       });
 
       it('should have emitted the `readable` event', () => {
@@ -334,6 +449,19 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -441,6 +569,19 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -550,8 +691,17 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
-      it('should have emitted the `end` event', () => {
-        iterator._eventCounts.end.should.equal(1);
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have ended', () => {
@@ -651,8 +801,8 @@ describe('TransformIterator', () => {
     describe('after the promise resolves', () => {
       before(() => resolvePromise(source));
 
-      it('should have called `read` on the source', () => {
-        source.read.should.have.been.calledOnce;
+      it('should have called `read` on the source once to read, once to end', () => {
+        source.read.should.have.been.calledTwice;
       });
 
       it('should have emitted the `readable` event', () => {
@@ -684,8 +834,17 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
-      it('should have emitted the `end` event', () => {
-        iterator._eventCounts.end.should.equal(1);
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have ended', () => {
@@ -702,7 +861,7 @@ describe('TransformIterator', () => {
     });
   });
 
-  describe('A TransformIterator with a promise and without autoStart', () => {
+  describe('A TransformIterator with a promise and without preBuffer', () => {
     let iterator, source, sourcePromise, resolvePromise;
     before(() => {
       source = new ArrayIterator(['a']);
@@ -711,7 +870,7 @@ describe('TransformIterator', () => {
       });
       sinon.spy(source, 'read');
       sinon.spy(sourcePromise, 'then');
-      iterator = new TransformIterator(sourcePromise, { autoStart: false });
+      iterator = new TransformIterator(sourcePromise, { preBuffer: false });
       captureEvents(iterator, 'readable', 'end');
     });
 
@@ -774,8 +933,8 @@ describe('TransformIterator', () => {
     describe('after the promise resolves', () => {
       before(() => resolvePromise(source));
 
-      it('should have called `read` on the source', () => {
-        source.read.should.have.been.calledOnce;
+      it('should have called `read` on the source once to read, once to end', () => {
+        source.read.should.have.been.calledTwice;
       });
 
       it('should have emitted another `readable` event', () => {
@@ -807,10 +966,20 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(2);
       });
 
-      it('should have emitted the `end` event', () => {
-        iterator._eventCounts.end.should.equal(1);
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
       });
 
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
+
       it('should have ended', () => {
         iterator.ended.should.be.true;
       });
@@ -888,8 +1057,8 @@ describe('TransformIterator', () => {
         createSource.should.have.been.calledOnce;
       });
 
-      it('should have called `read` on the source', () => {
-        source.read.should.have.been.calledOnce;
+      it('should have called `read` on the source once to read, once to end', () => {
+        source.read.should.have.been.calledTwice;
       });
 
       it('should have emitted the `readable` event', () => {
@@ -926,6 +1095,19 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
       it('should have emitted the `end` event', () => {
         iterator._eventCounts.end.should.equal(1);
       });
@@ -987,8 +1169,8 @@ describe('TransformIterator', () => {
     describe('after the promise resolves', () => {
       before(() => resolvePromise(source));
 
-      it('should have called `read` on the source', () => {
-        source.read.should.have.been.calledOnce;
+      it('should have called `read` on the source once to read, once to end', () => {
+        source.read.should.have.been.calledTwice;
       });
 
       it('should have emitted the `readable` event', () => {
@@ -1020,10 +1202,20 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(1);
       });
 
-      it('should have emitted the `end` event', () => {
-        iterator._eventCounts.end.should.equal(1);
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
       });
 
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
+
       it('should have ended', () => {
         iterator.ended.should.be.true;
       });
@@ -1038,7 +1230,7 @@ describe('TransformIterator', () => {
     });
   });
 
-  describe('A TransformIterator with a source creation function and without autoStart', () => {
+  describe('A TransformIterator with a source creation function and without preBuffer', () => {
     let iterator, source, createSource, sourcePromise, resolvePromise;
     before(() => {
       source = new ArrayIterator(['a']);
@@ -1047,7 +1239,7 @@ describe('TransformIterator', () => {
         resolvePromise = resolve;
       });
       createSource = sinon.spy(() => sourcePromise);
-      iterator = new TransformIterator({ autoStart: false, source: createSource });
+      iterator = new TransformIterator({ preBuffer: false, source: createSource });
       captureEvents(iterator, 'readable', 'end');
     });
 
@@ -1110,8 +1302,8 @@ describe('TransformIterator', () => {
     describe('after the promise resolves', () => {
       before(() => resolvePromise(source));
 
-      it('should have called `read` on the source', () => {
-        source.read.should.have.been.calledOnce;
+      it('should have called `read` on the source once to read, once to end', () => {
+        source.read.should.have.been.calledTwice;
       });
 
       it('should have emitted another `readable` event', () => {
@@ -1143,10 +1335,20 @@ describe('TransformIterator', () => {
         iterator._eventCounts.readable.should.equal(2);
       });
 
-      it('should have emitted the `end` event', () => {
-        iterator._eventCounts.end.should.equal(1);
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
       });
 
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
+      });
+
+
       it('should have ended', () => {
         iterator.ended.should.be.true;
       });
@@ -1165,7 +1367,7 @@ describe('TransformIterator', () => {
     let iterator, source;
     before(() => {
       source = new ArrayIterator([1, 2, 3]);
-      iterator = new TransformIterator(source, { autoStart: false });
+      iterator = new TransformIterator(source, { preBuffer: false });
     });
 
     describe('after being closed', () => {
@@ -1173,6 +1375,7 @@ describe('TransformIterator', () => {
         iterator.read();
         iterator.close();
         iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should have destroyed the source', () => {
@@ -1185,7 +1388,7 @@ describe('TransformIterator', () => {
     let iterator, source;
     before(() => {
       source = new ArrayIterator([1, 2, 3]);
-      iterator = new TransformIterator(source, { autoStart: false, destroySource: false });
+      iterator = new TransformIterator(source, { preBuffer: false, destroySource: false });
     });
 
     describe('after being closed', () => {
@@ -1193,6 +1396,7 @@ describe('TransformIterator', () => {
         iterator.read();
         iterator.close();
         iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should not have destroyed the source', () => {
@@ -1252,6 +1456,7 @@ describe('TransformIterator', () => {
           source.removeListener('error', noop);
           done();
         });
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should not re-emit the error', () => {
@@ -1405,8 +1610,21 @@ describe('TransformIterator', () => {
         source.read.should.have.been.calledOnce;
       });
 
-      it('should have emitted the `end` event', () => {
-        iterator._eventCounts.end.should.equal(1);
+      it('should have emitted the `readable` event', () => {
+        iterator._eventCounts.readable.should.equal(1);
+      });
+
+      it('should not have emitted the `end` event', () => {
+        iterator._eventCounts.end.should.equal(0);
+      });
+
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('emit end once data is subscribed', done => {
+        iterator.on('end', done);
+        iterator.on('data', () => { throw new Error('should not emit data'); });
       });
 
       it('should not be readable', () => {
@@ -1505,7 +1723,7 @@ describe('TransformIterator', () => {
     });
   });
 
-  describe('Two transformers in sequence with autostart', () => {
+  describe('Two transformers in sequence with preBuffer', () => {
     let source, transform1, transform2, callback;
     before(() => {
       source = new ArrayIterator([]);
@@ -1513,6 +1731,7 @@ describe('TransformIterator', () => {
       transform2 = new TransformIterator(transform1);
       callback = sinon.spy();
       transform2.on('end', callback);
+      transform2.on('data', () => { throw new Error('should not emit data'); });
     });
 
     describe('before attaching a data listener', () => {
@@ -1522,12 +1741,12 @@ describe('TransformIterator', () => {
     });
   });
 
-  describe('Two transformers in sequence without autostart', () => {
+  describe('Two transformers in sequence without preBuffer', () => {
     let source, transform1, transform2, callback;
     before(() => {
       source = new ArrayIterator([]);
-      transform1 = new TransformIterator(source, { autoStart: false });
-      transform2 = new TransformIterator(transform1, { autoStart: false });
+      transform1 = new TransformIterator(source, { preBuffer: false });
+      transform2 = new TransformIterator(transform1, { preBuffer: false });
       callback = sinon.spy();
       transform2.on('end', callback);
     });
@@ -1539,8 +1758,9 @@ describe('TransformIterator', () => {
     });
 
     describe('after attaching a data listener', () => {
-      before(() => {
+      before(done => {
         transform2.on('data', sinon.spy());
+        transform2.on('end', done);
       });
 
       it('should have emitted the end event', () => {
diff --git a/test/UnionIterator-test.js b/test/UnionIterator-test.js
index 308f52d..d8e8214 100644
--- a/test/UnionIterator-test.js
+++ b/test/UnionIterator-test.js
@@ -10,6 +10,7 @@ import {
 } from '../dist/asynciterator.js';
 
 import { EventEmitter } from 'events';
+import { expect } from 'chai';
 
 describe('UnionIterator', () => {
   describe('The UnionIterator function', () => {
@@ -68,6 +69,31 @@ describe('UnionIterator', () => {
     (await toArray(iterator)).sort().should.eql([0, 1, 2]);
   });
 
+  it('should include all data from 1 non-empty and 3 normal empty sources and one empty source that is done', async () => {
+    const empty = new EmptyIterator();
+    empty.read();
+    empty.read();
+    expect(empty.done).to.be.true;
+
+    const iterator = new UnionIterator([
+      empty,
+      new EmptyIterator(),
+      range(0, 2),
+      new EmptyIterator(),
+      new EmptyIterator(),
+    ]);
+    (await toArray(iterator)).sort().should.eql([0, 1, 2]);
+  });
+
+  it('taking union over completed empty iterator', async () => {
+    const empty = new EmptyIterator();
+    empty.read();
+    expect(empty.done).to.be.true;
+
+    const iterator = new UnionIterator(empty);
+    (await toArray(iterator)).sort().should.eql([]);
+  });
+
   describe('when constructed with an array of 0 sources', () => {
     let iterator;
     before(() => {
@@ -75,16 +101,24 @@ describe('UnionIterator', () => {
       iterator = new UnionIterator(sources);
     });
 
+    it('should not have ended', () => {
+      iterator.ended.should.be.false;
+    });
+
+    it('should read null', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
     it('should have ended', () => {
       iterator.ended.should.be.true;
     });
   });
 
-  describe('when constructed with an array of 0 sources without autoStart', () => {
+  describe('when constructed with an array of 0 sources without preBuffer', () => {
     let iterator;
     before(() => {
       const sources = [];
-      iterator = new UnionIterator(sources, { autoStart: false });
+      iterator = new UnionIterator(sources, { preBuffer: false });
     });
 
     describe('before reading', () => {
@@ -99,6 +133,14 @@ describe('UnionIterator', () => {
         scheduleTask(done);
       });
 
+      it('should not have ended', () => {
+        iterator.ended.should.be.false;
+      });
+
+      it('should read null', () => {
+        expect(iterator.read()).to.be.null;
+      });
+
       it('should have ended', () => {
         iterator.ended.should.be.true;
       });
@@ -135,6 +177,14 @@ describe('UnionIterator', () => {
       iterator = new UnionIterator(new EmptyIterator());
     });
 
+    it('should not have ended', () => {
+      iterator.ended.should.be.false;
+    });
+
+    it('should read null', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
     it('should have ended', () => {
       iterator.ended.should.be.true;
     });
@@ -147,16 +197,45 @@ describe('UnionIterator', () => {
       iterator = new UnionIterator(new ArrayIterator(sources));
     });
 
+    it('should not have ended', () => {
+      iterator.ended.should.be.false;
+    });
+
+    it('should read null', () => {
+      expect(iterator.read()).to.be.null;
+    });
+
     it('should have ended', () => {
       iterator.ended.should.be.true;
     });
   });
 
-  describe('when constructed with an iterator of 0 sources without autoStart', () => {
+  describe('when constructed with an iterator of 0 sources', () => {
     let iterator;
     before(() => {
       const sources = [];
-      iterator = new UnionIterator(new ArrayIterator(sources), { autoStart: false });
+      iterator = new UnionIterator(new ArrayIterator(sources), { preBuffer: false });
+    });
+
+    it('should not have ended', () => {
+      iterator.ended.should.be.false;
+    });
+
+    it('emit end once data is subscribed', done => {
+      iterator.on('end', done);
+      iterator.on('data', () => { throw new Error('should not emit data'); });
+    });
+
+    it('should have ended', () => {
+      iterator.ended.should.be.true;
+    });
+  });
+
+  describe('when constructed with an iterator of 0 sources without preBuffer', () => {
+    let iterator;
+    before(() => {
+      const sources = [];
+      iterator = new UnionIterator(new ArrayIterator(sources), { preBuffer: false });
     });
 
     describe('before reading', () => {
@@ -171,6 +250,10 @@ describe('UnionIterator', () => {
         scheduleTask(done);
       });
 
+      it('should read null', () => {
+        expect(iterator.read()).to.be.null;
+      });
+
       it('should have ended', () => {
         iterator.ended.should.be.true;
       });
@@ -216,13 +299,13 @@ describe('UnionIterator', () => {
     });
   });
 
-  describe('when constructed with an iterator and with autoStart', () => {
+  describe('when constructed with an iterator and with preBuffer', () => {
     let iterator, sourceIterator;
     before(() => {
       const sources = [range(0, 2), range(3, 6)];
       sourceIterator = new ArrayIterator(sources);
       sinon.spy(sourceIterator, 'read');
-      iterator = new UnionIterator(sourceIterator, { autoStart: true });
+      iterator = new UnionIterator(sourceIterator, { preBuffer: true });
     });
 
     describe('before reading', () => {
@@ -260,13 +343,13 @@ describe('UnionIterator', () => {
     });
   });
 
-  describe('when constructed with an iterator and without autoStart', () => {
+  describe('when constructed with an iterator and without preBuffer', () => {
     let iterator, sourceIterator;
     before(() => {
       const sources = [range(0, 2), range(3, 6)];
       sourceIterator = new ArrayIterator(sources);
       sinon.spy(sourceIterator, 'read');
-      iterator = new UnionIterator(sourceIterator, { autoStart: false });
+      iterator = new UnionIterator(sourceIterator, { preBuffer: false });
     });
 
     describe('before reading', () => {
diff --git a/test/integration-test.js b/test/integration-test.js
index ba45ea5..d882c6d 100644
--- a/test/integration-test.js
+++ b/test/integration-test.js
@@ -6,13 +6,13 @@ import {
 } from '../dist/asynciterator.js';
 
 describe('Integration tests', () => {
-  describe('A sequence of ArrayIterator, TransformIterator, and Unioniterator without autoStart', () => {
+  describe('A sequence of ArrayIterator, TransformIterator, and Unioniterator without preBuffer', () => {
     let arrayIterator, transformIterator, unionIterator;
 
     before(() => {
-      arrayIterator = new ArrayIterator([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], { autoStart: false });
-      transformIterator = new TransformIterator(arrayIterator, { autoStart: false });
-      unionIterator = new UnionIterator([transformIterator], { autoStart: false });
+      arrayIterator = new ArrayIterator([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], { preBuffer: false });
+      transformIterator = new TransformIterator(arrayIterator, { preBuffer: false });
+      unionIterator = new UnionIterator([transformIterator], { preBuffer: false });
     });
 
     it('emits a data event', done => {
@@ -26,11 +26,11 @@ describe('Integration tests', () => {
   });
 
   describe('Cloning iterators', () => {
-    describe('A clone of an empty ArrayIterator without autoStart', () => {
+    describe('A clone of an empty ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(() => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
         clonedIterator = arrayIterator.clone();
       });
 
@@ -40,11 +40,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('An async clone of an empty ArrayIterator without autoStart', () => {
+    describe('An async clone of an empty ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(async () => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
         await new Promise(scheduleTask);
 
         clonedIterator = arrayIterator.clone();
@@ -56,11 +56,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A multi-clone of an empty ArrayIterator without autoStart', () => {
+    describe('A multi-clone of an empty ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator1, clonedIterator2;
 
       before(() => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
         clonedIterator1 = arrayIterator.clone();
         clonedIterator2 = arrayIterator.clone();
       });
@@ -76,11 +76,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('An async multi-clone of an empty ArrayIterator without autoStart', () => {
+    describe('An async multi-clone of an empty ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator1, clonedIterator2;
 
       before(async () => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
         await new Promise(resolve => scheduleTask(resolve));
 
         clonedIterator1 = arrayIterator.clone();
@@ -98,11 +98,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A double clone of an empty ArrayIterator without autoStart', () => {
+    describe('A double clone of an empty ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(() => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
         clonedIterator = arrayIterator.clone().clone();
       });
 
@@ -112,12 +112,12 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A clone of a sequence of an empty ArrayIterator, and TransformIterator without autoStart', () => {
+    describe('A clone of a sequence of an empty ArrayIterator, and TransformIterator without preBuffer', () => {
       let arrayIterator, transformIterator, clonedIterator;
 
       before(() => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
-        transformIterator = new TransformIterator(arrayIterator, { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
+        transformIterator = new TransformIterator(arrayIterator, { preBuffer: false });
         clonedIterator = transformIterator.clone();
       });
 
@@ -127,13 +127,13 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A clone of a sequence of an empty ArrayIterator, TransformIterator, and Unioniterator without autoStart', () => {
+    describe('A clone of a sequence of an empty ArrayIterator, TransformIterator, and Unioniterator without preBuffer', () => {
       let arrayIterator, transformIterator, unionIterator, clonedIterator;
 
       before(() => {
-        arrayIterator = new ArrayIterator([], { autoStart: false });
-        transformIterator = new TransformIterator(arrayIterator, { autoStart: false });
-        unionIterator = new UnionIterator([transformIterator], { autoStart: false });
+        arrayIterator = new ArrayIterator([], { preBuffer: false });
+        transformIterator = new TransformIterator(arrayIterator, { preBuffer: false });
+        unionIterator = new UnionIterator([transformIterator], { preBuffer: false });
         clonedIterator = unionIterator.clone();
       });
 
@@ -143,11 +143,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A clone of an ArrayIterator without autoStart', () => {
+    describe('A clone of an ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(() => {
-        arrayIterator = new ArrayIterator([1, 2, 3], { autoStart: false });
+        arrayIterator = new ArrayIterator([1, 2, 3], { preBuffer: false });
         clonedIterator = arrayIterator.clone();
       });
 
@@ -157,11 +157,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('An async clone of an ArrayIterator without autoStart', () => {
+    describe('An async clone of an ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(async () => {
-        arrayIterator = new ArrayIterator([1, 2, 3], { autoStart: false });
+        arrayIterator = new ArrayIterator([1, 2, 3], { preBuffer: false });
         await new Promise(scheduleTask);
 
         clonedIterator = arrayIterator.clone();
@@ -173,11 +173,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A double clone of an ArrayIterator without autoStart', () => {
+    describe('A double clone of an ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(() => {
-        arrayIterator = new ArrayIterator([1, 2, 3], { autoStart: false });
+        arrayIterator = new ArrayIterator([1, 2, 3], { preBuffer: false });
         clonedIterator = arrayIterator.clone().clone();
       });
 
@@ -187,11 +187,11 @@ describe('Integration tests', () => {
       });
     });
 
-    describe('A double async clone of an ArrayIterator without autoStart', () => {
+    describe('A double async clone of an ArrayIterator without preBuffer', () => {
       let arrayIterator, clonedIterator;
 
       before(async () => {
-        arrayIterator = new ArrayIterator([1, 2, 3], { autoStart: false });
+        arrayIterator = new ArrayIterator([1, 2, 3], { preBuffer: false });
         clonedIterator = arrayIterator.clone();
         await new Promise(scheduleTask);