fixes

index.es6.js

@@ -1,9 +1,9 @@
 export const
   { ReadableStream } = require('./spec/reference-implementation/lib/readable-stream'),
   { WritableStream } = require('./spec/reference-implementation/lib/writable-stream'),
-  ByteLengthQueuingStrategy = require('./spec/reference-implementation/lib/byte-length-queuing-strategy'),
-  CountQueuingStrategy = require('./spec/reference-implementation/lib/count-queuing-strategy'),
-  TransformStream = require('./spec/reference-implementation/lib/transform-stream').TransformStream;
+  { ByteLengthQueuingStrategy } = require('./spec/reference-implementation/lib/byte-length-queuing-strategy'),
+  { CountQueuingStrategy } = require('./spec/reference-implementation/lib/count-queuing-strategy'),
+  { TransformStream } = require('./spec/reference-implementation/lib/transform-stream');
 
 const interfaces = {
   ReadableStream,
@@ -16,6 +16,31 @@ const interfaces = {
 // Export
 export default interfaces;
 
+function getGlobals(){
+  if(typeof self !== 'undefined'){
+    return self;
+  }else if(typeof window !== 'undefined'){
+    return window;
+  }else if(typeof global !== 'undefined'){
+    return global;
+  }
+}
+
+function assignInterfaces(globals, interfaces){
+  for(let i in interfaces){
+    // prefer native implementation if available
+    if(typeof globals[i] === 'undefined'){
+      globals[i] = interfaces[i];
+    }else{
+      let _forcePolyfill = function(){
+        globals[i] = interfaces[i];
+      }
+      globals[i].forcePolyfill = _forcePolyfill;
+      globals[i].prototype.forcePolyfill = _forcePolyfill;
+    }
+  }
+}
+
+const globals = getGlobals();
 // Add classes to window
-if ( typeof window !== "undefined" )
-  Object.assign( window, interfaces );
+assignInterfaces(globals, interfaces);

package.json

@@ -46,5 +46,7 @@
     "uglifyify": "^3.0.2",
     "yarn": "^0.17.0"
   },
-  "dependencies": {}
+  "dependencies": {
+    "better-assert": "^1.0.2"
+  }
 }