Rewrite async-spec-helpers in javascript

Signed-off-by: Nathan Sobo <nathan@github.com>

spec/async-spec-helpers.coffee

@@ -1,30 +0,0 @@
-exports.beforeEach = (fn) ->
-  global.beforeEach ->
-    result = fn()
-    if result instanceof Promise
-      waitsForPromise(-> result)
-
-exports.afterEach = (fn) ->
-  global.afterEach ->
-    result = fn()
-    if result instanceof Promise
-      waitsForPromise(-> result)
-
-['it', 'fit', 'ffit', 'fffit'].forEach (name) ->
-  exports[name] = (description, fn) ->
-    global[name] description, ->
-      result = fn()
-      if result instanceof Promise
-        waitsForPromise(-> result)
-
-waitsForPromise = (fn) ->
-  promise = fn()
-  # This timeout is 3 minutes. We need to bump it back down once we fix backgrounding
-  # of the renderer process on CI. See https://github.com/atom/electron/issues/4317
-  waitsFor 'spec promise to resolve', 3 * 60 * 1000, (done) ->
-    promise.then(
-      done,
-      (error) ->
-        jasmine.getEnv().currentSpec.fail(error)
-        done()
-    )

spec/async-spec-helpers.js

@@ -0,0 +1,42 @@
+/** @babel */
+
+export function beforeEach (fn) {
+  global.beforeEach(function () {
+    const result = fn()
+    if (result instanceof Promise) {
+      waitsForPromise(() => result)
+    }
+  })
+}
+
+export function afterEach (fn) {
+  global.afterEach(function () {
+    const result = fn()
+    if (result instanceof Promise) {
+      waitsForPromise(() => result)
+    }
+  })
+}
+
+['it', 'fit', 'ffit', 'fffit'].forEach(function (name) {
+  module.exports[name] = function (description, fn) {
+    global[name](description, function () {
+      const result = fn()
+      if (result instanceof Promise) {
+        waitsForPromise(() => result)
+      }
+    })
+  }
+})
+
+function waitsForPromise (fn) {
+  const promise = fn()
+  // This timeout is 3 minutes. We need to bump it back down once we fix
+  // backgrounding of the renderer process on CI. See https://github.com/atom/electron/issues/4317
+  global.waitsFor('spec promise to resolve', 3 * 60 * 1000, function (done) {
+    promise.then(done, function (error) {
+      jasmine.getEnv().currentSpec.fail(error)
+      done()
+    })
+  })
+}