Merge pull request #339 from atom/wl-async-await-specs

Use async/await in specs

spec/async-spec-helpers.js

@@ -0,0 +1,103 @@
+/** @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) {
+    if (fn === undefined) {
+      global[name](description)
+      return
+    }
+
+    global[name](description, function () {
+      const result = fn()
+      if (result instanceof Promise) {
+        waitsForPromise(() => result)
+      }
+    })
+  }
+})
+
+export async function conditionPromise (condition, description = 'anonymous condition') {
+  const startTime = Date.now()
+
+  while (true) {
+    await timeoutPromise(100)
+
+    if (await condition()) {
+      return
+    }
+
+    if (Date.now() - startTime > 5000) {
+      throw new Error('Timed out waiting on ' + description)
+    }
+  }
+}
+
+export function timeoutPromise (timeout) {
+  return new Promise(function (resolve) {
+    global.setTimeout(resolve, timeout)
+  })
+}
+
+function waitsForPromise (fn) {
+  const promise = fn()
+  global.waitsFor('spec promise to resolve', function (done) {
+    promise.then(done, function (error) {
+      jasmine.getEnv().currentSpec.fail(error)
+      done()
+    })
+  })
+}
+
+export function emitterEventPromise (emitter, event, timeout = 15000) {
+  return new Promise((resolve, reject) => {
+    const timeoutHandle = setTimeout(() => {
+      reject(new Error(`Timed out waiting for '${event}' event`))
+    }, timeout)
+    emitter.once(event, () => {
+      clearTimeout(timeoutHandle)
+      resolve()
+    })
+  })
+}
+
+export function promisify (original) {
+  return function (...args) {
+    return new Promise((resolve, reject) => {
+      args.push((err, ...results) => {
+        if (err) {
+          reject(err)
+        } else {
+          resolve(...results)
+        }
+      })
+
+      return original(...args)
+    })
+  }
+}
+
+export function promisifySome (obj, fnNames) {
+  const result = {}
+  for (const fnName of fnNames) {
+    result[fnName] = promisify(obj[fnName])
+  }
+  return result
+}