Check in codegen test expectations.

test/codegen/expect/language/type_check_test.js

Index: test/codegen/expect/language/type_check_test.js
diff --git a/test/codegen/expect/language/type_check_test.js b/test/codegen/expect/language/type_check_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..7ace4e9ec7e4ea8a12e34fb0464ef8cc74935988
--- /dev/null
+++ b/test/codegen/expect/language/type_check_test.js
@@ -0,0 +1,27 @@
+dart_library.library('language/type_check_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__type_check_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const _interceptors = dart_sdk._interceptors;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const type_check_test = Object.create(null);
+  let JSArrayOfA = () => (JSArrayOfA = dart.constFn(_interceptors.JSArray$(type_check_test.A)))();
+  let VoidToB = () => (VoidToB = dart.constFn(dart.definiteFunctionType(type_check_test.B, [])))();
+  let dynamicTobool = () => (dynamicTobool = dart.constFn(dart.definiteFunctionType(core.bool, [dart.dynamic])))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  type_check_test.A = class A extends core.Object {};
+  type_check_test.B = class B extends type_check_test.A {};
+  type_check_test.main = function() {
+    let a = JSArrayOfA().of([new type_check_test.A(), new type_check_test.B()]);
+    let b = a[dartx.get](0);
+    b = b;
+    expect$.Expect.throws(dart.fn(() => type_check_test.B.as(b), VoidToB()), dart.fn(e => core.CastError.is(e), dynamicTobool()));
+  };
+  dart.fn(type_check_test.main, VoidTodynamic());
+  // Exports:
+  exports.type_check_test = type_check_test;
+});