Convert testing fetch under Web Workers to Karma

package.json

@@ -29,6 +29,6 @@
   "scripts": {
     "prepublish": "make dist/fetch.umd.js",
     "pretest": "make",
-    "test": "karma start ./test/karma.config.js"
+    "test": "karma start ./test/karma.config.js && karma start ./test/karma-worker.config.js"
   }
 }

test/karma-worker.config.js

+const parentConfig = require('./karma.config')
+
+module.exports = function(config) {
+  parentConfig(config)
+  config.set({
+    frameworks: ['mocha'],
+    files: [
+      'test/worker-adapter.js',
+      {
+        pattern: '{test,dist}/*.js',
+        included: false
+      },
+      {
+        pattern: 'node_modules/{mocha,chai}/*.js',
+        included: false,
+        watched: false
+      }
+    ]
+  })
+}

test/karma.config.js

@@ -2,13 +2,14 @@ const serverEndpoints = require('./server')
 
 module.exports = function(config) {
   config.set({
+    basePath: '..',
     frameworks: ['mocha', 'chai'],
     client: {
       mocha: {
         ui: 'tdd'
       }
     },
-    files: ['../dist/fetch.umd.js', 'test.js'],
+    files: ['dist/fetch.umd.js', 'test/test.js'],
     reporters: ['progress'],
     port: 9876,
     colors: true,

test/worker-adapter.js

+/* global Mocha */
+
+var mochaRun = mocha.run
+mocha.run = function() {}
+
+mocha.suite.suites.unshift(Mocha.Suite.create(mocha.suite, 'worker'))
+
+var worker = new Worker('/base/test/worker.js')
+
+worker.addEventListener('message', function(e) {
+  switch (e.data.name) {
+    case 'pass':
+      test(e.data.title, function() {})
+      break
+    case 'pending':
+      test(e.data.title)
+      break
+    case 'fail':
+      test(e.data.title, function() {
+        var err = new Error(e.data.message)
+        err.stack = e.data.stack
+        throw err
+      })
+      break
+    case 'end':
+      mochaRun()
+      break
+  }
+})

test/worker.js

-importScripts('/node_modules/chai/chai.js')
-importScripts('/node_modules/mocha/mocha.js')
+importScripts('/base/node_modules/mocha/mocha.js')
+importScripts('/base/node_modules/chai/chai.js')
 
 mocha.setup('tdd')
 self.assert = chai.assert
 
-importScripts('/node_modules/promise-polyfill/promise.js')
-importScripts('/node_modules/abortcontroller-polyfill/dist/abortcontroller-polyfill-only.js')
-importScripts('/dist/fetch.umd.js')
-importScripts('/test/test.js')
+importScripts('/base/dist/fetch.umd.js')
+importScripts('/base/test/test.js')
 
 function title(test) {
   return test.fullTitle().replace(/#/g, '')