Merge pull request #5891 from spalger/implement/mochaSetup

formalize mocha setup

package.json

@@ -56,8 +56,8 @@
     "elasticsearchWithPlugins": "grunt esvm:withPlugins:keepalive",
     "lint": "grunt eslint:source",
     "lintroller": "grunt eslint:fixSource",
-    "mocha": "mocha --compilers js:babel/register",
-    "mocha:debug": "mocha --debug-brk --compilers js:babel/register"
+    "mocha": "mocha",
+    "mocha:debug": "mocha --debug-brk"
   },
   "repository": {
     "type": "git",

tasks/config/simplemocha.js

@@ -1,3 +1,5 @@
+require('../../test/mocha_setup');
+
 module.exports = {
   options: {
     timeout: 10000,

test/mocha.opts

@@ -0,0 +1 @@
+--require test/mocha_setup.js

test/mocha_setup.js

@@ -0,0 +1,41 @@
+var sinon = require('sinon');
+var autoRelease = require('auto-release-sinon');
+
+require('babel/register')(require('../src/optimize/babelOptions').node);
+
+// hook into the global afterEach variable to allow autoReleaseSinon to register
+// an afterEach handler before mocha has exposed itself to the test files.
+//
+// This works by telling autoReleaseSinon to use a fake "afterEach" function.
+// Rather than actually record an afterEach handler the function tracks all of
+// the calls it received and queues them up in queuedAfterEachArgs.
+//
+// The global "afterEach" variable is also tracked, and once it is assigned by mocha
+// the variable global is reconfigured to point directly to the new value (from mocha)
+// and all of the queued invocations are executed.
+var queuedAfterEachArgs = [];
+Object.defineProperty(global, 'afterEach', {
+  configurable: true,
+  get() { return undefined; },
+  set(afterEach) {
+    Object.defineProperty(global, 'afterEach', {
+      configurable: true,
+      writable: true,
+      value: afterEach
+    });
+
+    queuedAfterEachArgs.forEach(function (args) {
+      afterEach.apply(null, args);
+    });
+
+    return global.afterEach;
+  }
+});
+
+autoRelease.setupAutoRelease(sinon, function () {
+  if (!global.afterEach) {
+    queuedAfterEachArgs.push(Array.prototype.slice.call(arguments));
+  } else {
+    global.afterEach.apply(this, arguments);
+  }
+});