use default options when none provided

dist/index.d.ts

@@ -1,6 +1,6 @@
 import ExtendableError from 'extendable-error';
 export interface ErrorConfig {
-    message: string;
+    message?: string;
     time_thrown?: string;
     data?: object;
     options?: {
@@ -25,7 +25,7 @@ export declare class ApolloError extends ExtendableError {
     locations: any;
     _showLocations: boolean;
     _showPath: boolean;
-    constructor(name: string, config: ErrorConfig);
+    constructor(name: string, baseConfig?: ErrorConfig, config?: ErrorConfig);
     serialize(): ErrorInfo;
 }
 export declare const isInstance: (e: any) => boolean;

src/index.ts

@@ -5,7 +5,7 @@ const isString = d => Object.prototype.toString.call(d) === '[object String]';
 const isObject = d => Object.prototype.toString.call(d) === '[object Object]';
 
 export interface ErrorConfig {
-  message: string;
+  message?: string;
   time_thrown?: string;
   data?: object;
   options?: {
@@ -33,22 +33,17 @@ export class ApolloError extends ExtendableError {
   _showLocations: boolean = false;
   _showPath: boolean = false;
 
-  constructor(name: string, config: ErrorConfig) {
-    super((arguments[2] && arguments[2].message) || '');
-
-    const t = (arguments[2] && arguments[2].time_thrown) || (new Date()).toISOString();
-    const m = (arguments[2] && arguments[2].message) || '';
-    const configData = (arguments[2] && arguments[2].data) || {};
-    const d = { ...this.data, ...configData };
-    const opts = ((arguments[2] && arguments[2].options) || {});
-
+  constructor(name: string, baseConfig: ErrorConfig = {}, config: ErrorConfig = {}) {
+    super(config.message || baseConfig.message || '');
+
+    const options = {...config.options, ...baseConfig.options};
 
     this.name = name;
-    this.message = m;
-    this.time_thrown = t;
-    this.data = d;
-    this._showLocations = !!opts.showLocations;
-    this._showPath = !!opts.showPath;
+    this.message = config.message || baseConfig.message || '';
+    this.time_thrown = config.time_thrown || baseConfig.time_thrown || new Date().toISOString();
+    this.data = {...baseConfig.data, ...config.data};
+    this._showLocations = !!options.showLocations;
+    this._showPath = !!options.showPath;
   }
 
   serialize(): ErrorInfo {

test/spec.js

@@ -40,6 +40,26 @@ describe('createError', () => {
         foo: 'bar'
       });
     });
+
+    it('uses original message and merges original data', () => {
+      const FooError = createError('FooError', {
+        message: 'A foo error has occurred',
+        data: {
+          hello: 'world'
+        },
+        options: {
+          showLocations: false,
+          showPath: true
+        }
+      });
+      const e = new FooError({data: {foo: 'bar'}});
+
+      const { message, name, time_thrown, data } = e.serialize();
+      expect(message).to.equal('A foo error has occurred');
+      expect(name).to.equal('FooError');
+      expect(time_thrown).to.equal(e.time_thrown);
+      expect(data).to.eql({ hello: 'world', foo: 'bar' });
+    });
   });
   context('when missing a config as the second parameter', () => {
     it('throws an assertion error with a useful message', () => {