Check in codegen test expectations.

test/codegen/expect/async_helper/async_helper.js

+dart_library.library('async_helper', null, /* Imports */[
+  'dart_sdk'
+], function load__async_helper(exports, dart_sdk) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const async_helper = Object.create(null);
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.functionType(dart.dynamic, [])))();
+  let StringToException = () => (StringToException = dart.constFn(dart.definiteFunctionType(core.Exception, [core.String])))();
+  let _Action0Tovoid = () => (_Action0Tovoid = dart.constFn(dart.definiteFunctionType(dart.void, [async_helper._Action0])))();
+  let VoidTovoid = () => (VoidTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [])))();
+  let dynamicTovoid = () => (dynamicTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [dart.dynamic])))();
+  let FnTovoid = () => (FnTovoid = dart.constFn(dart.definiteFunctionType(dart.void, [VoidTodynamic()])))();
+  async_helper._initialized = false;
+  async_helper._Action0 = dart.typedef('_Action0', () => dart.functionType(dart.void, []));
+  async_helper._onAsyncEnd = null;
+  async_helper._asyncLevel = 0;
+  async_helper._buildException = function(msg) {
+    return core.Exception.new(dart.str`Fatal: ${msg}. This is most likely a bug in your test.`);
+  };
+  dart.fn(async_helper._buildException, StringToException());
+  async_helper.asyncTestInitialize = function(callback) {
+    async_helper._asyncLevel = 0;
+    async_helper._initialized = false;
+    async_helper._onAsyncEnd = callback;
+  };
+  dart.fn(async_helper.asyncTestInitialize, _Action0Tovoid());
+  dart.copyProperties(async_helper, {
+    get asyncTestStarted() {
+      return async_helper._initialized;
+    }
+  });
+  async_helper.asyncStart = function() {
+    if (dart.test(async_helper._initialized) && async_helper._asyncLevel == 0) {
+      dart.throw(async_helper._buildException('asyncStart() was called even though we are done ' + 'with testing.'));
+    }
+    if (!dart.test(async_helper._initialized)) {
+      if (async_helper._onAsyncEnd == null) {
+        dart.throw(async_helper._buildException('asyncStart() was called before asyncTestInitialize()'));
+      }
+      core.print('unittest-suite-wait-for-done');
+      async_helper._initialized = true;
+    }
+    async_helper._asyncLevel = dart.notNull(async_helper._asyncLevel) + 1;
+  };
+  dart.fn(async_helper.asyncStart, VoidTovoid());
+  async_helper.asyncEnd = function() {
+    if (dart.notNull(async_helper._asyncLevel) <= 0) {
+      if (!dart.test(async_helper._initialized)) {
+        dart.throw(async_helper._buildException('asyncEnd() was called before asyncStart().'));
+      } else {
+        dart.throw(async_helper._buildException('asyncEnd() was called more often than ' + 'asyncStart().'));
+      }
+    }
+    async_helper._asyncLevel = dart.notNull(async_helper._asyncLevel) - 1;
+    if (async_helper._asyncLevel == 0) {
+      let callback = async_helper._onAsyncEnd;
+      async_helper._onAsyncEnd = null;
+      callback();
+      core.print('unittest-suite-success');
+    }
+  };
+  dart.fn(async_helper.asyncEnd, VoidTovoid());
+  async_helper.asyncSuccess = function(_) {
+    return async_helper.asyncEnd();
+  };
+  dart.fn(async_helper.asyncSuccess, dynamicTovoid());
+  async_helper.asyncTest = function(f) {
+    async_helper.asyncStart();
+    dart.dsend(f(), 'then', async_helper.asyncSuccess);
+  };
+  dart.fn(async_helper.asyncTest, FnTovoid());
+  // Exports:
+  exports.async_helper = async_helper;
+});