Check in codegen test expectations.

test/codegen/expect/language/issue12284_test.js

Index: test/codegen/expect/language/issue12284_test.js
diff --git a/test/codegen/expect/language/issue12284_test.js b/test/codegen/expect/language/issue12284_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..894452c7aff508c8be4001c9aad9036bfc8500ce
--- /dev/null
+++ b/test/codegen/expect/language/issue12284_test.js
@@ -0,0 +1,48 @@
+dart_library.library('language/issue12284_test', null, /* Imports */[
+  'dart_sdk',
+  'expect'
+], function load__issue12284_test(exports, dart_sdk, expect) {
+  'use strict';
+  const core = dart_sdk.core;
+  const dart = dart_sdk.dart;
+  const dartx = dart_sdk.dartx;
+  const expect$ = expect.expect;
+  const issue12284_test = Object.create(null);
+  const compiler_annotations = Object.create(null);
+  let VoidToint = () => (VoidToint = dart.constFn(dart.definiteFunctionType(core.int, [])))();
+  let VoidToA = () => (VoidToA = dart.constFn(dart.definiteFunctionType(issue12284_test.A, [])))();
+  let dynamicTobool = () => (dynamicTobool = dart.constFn(dart.definiteFunctionType(core.bool, [dart.dynamic])))();
+  let VoidTodynamic = () => (VoidTodynamic = dart.constFn(dart.definiteFunctionType(dart.dynamic, [])))();
+  issue12284_test.A = class A extends core.Object {
+    new(param) {
+      this.field = null;
+      let bar = dart.fn(() => 42, VoidToint());
+      this.field = core.int._check(dart.dsend(param, '+', 42));
+    }
+    redirect() {
+      A.prototype.new.call(this, 'foo');
+    }
+  };
+  dart.defineNamedConstructor(issue12284_test.A, 'redirect');
+  dart.setSignature(issue12284_test.A, {
+    constructors: () => ({
+      new: dart.definiteFunctionType(issue12284_test.A, [dart.dynamic]),
+      redirect: dart.definiteFunctionType(issue12284_test.A, [])
+    })
+  });
+  issue12284_test.main = function() {
+    expect$.Expect.equals(42 + 42, new issue12284_test.A(42).field);
+    expect$.Expect.throws(dart.fn(() => new issue12284_test.A.redirect(), VoidToA()), dart.fn(e => core.ArgumentError.is(e) || core.TypeError.is(e) || core.NoSuchMethodError.is(e), dynamicTobool()));
+  };
+  dart.fn(issue12284_test.main, VoidTodynamic());
+  compiler_annotations.DontInline = class DontInline extends core.Object {
+    new() {
+    }
+  };
+  dart.setSignature(compiler_annotations.DontInline, {
+    constructors: () => ({new: dart.definiteFunctionType(compiler_annotations.DontInline, [])})
+  });
+  // Exports:
+  exports.issue12284_test = issue12284_test;
+  exports.compiler_annotations = compiler_annotations;
+});