cpsir unittests: move all unittests into individual files and test runners.

tests/compiler/dart2js/cps_ir/runner.dart

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Test that the CPS IR code generator compiles programs and produces the
+// the expected output.
+
+import 'dart:io';
+
+import 'package:async_helper/async_helper.dart';
+import 'package:expect/expect.dart';
+import 'package:compiler/src/apiimpl.dart' show
+    CompilerImpl;
+import '../memory_compiler.dart';
+import 'package:compiler/src/js/js.dart' as js;
+import 'package:compiler/src/elements/elements.dart' show
+    ClassElement,
+    Element;
+
+// Regular experession used to extract the method name that is used to match the
+// test output. By default we match the output of main.
+final RegExp elementNameRegExp = new RegExp(r'^// Method to test: (.*)$',
+    multiLine: true);
+
+runTest(String filename, {bool update: false}) {
+  var outputname = filename.replaceFirst('.dart', '.js');
+  String source = new File.fromUri(Platform.script.resolve('input/$filename'))
+      .readAsStringSync();
+  var expectedFile =
+      new File.fromUri(Platform.script.resolve('expected/$outputname'));
+  String expected = expectedFile.existsSync()
+    ? expectedFile.readAsStringSync() : '';
+  var match = elementNameRegExp.firstMatch(source);
+  var elementName = match?.group(1);
+
+  Map files = {TEST_MAIN_FILE: source};
+  asyncTest(() async {
+    Uri uri = Uri.parse('memory:$TEST_MAIN_FILE');
+    String found = null;
+    try {
+      CompilationResult result = await runCompiler(
+          entryPoint: uri,
+          memorySourceFiles: files,
+          options: <String>['--use-cps-ir']);
+      Expect.isTrue(result.isSuccess);
+      CompilerImpl compiler = result.compiler;
+      if (expected != null) {
+        String output = elementName == null
+            ? _getCodeForMain(compiler)
+            : _getCodeForMethod(compiler, elementName);
+        // Include the input in a comment of the expected file to make it easier
+        // to see the relation between input and output in code reviews.
+        found = '// Expectation for test: \n'
+            '// ${source.trim().replaceAll('\n', '\n// ')}\n\n'
+            '$output\n';
+      }
+    } catch (e, st) {
+      print(e);
+      print(st);
+      var message = 'The following test failed to compile:\n'
+                    '${_formatTest(files)}';
+      if (update) {
+        print('\n\n$message\n');
+        return;
+      } else {
+        Expect.fail(message);
+      }
+    }
+    if (expected != found) {
+      if (update) {
+        expectedFile.writeAsStringSync(found);
+        print('INFO: $expectedFile was updated');
+      } else {
+        Expect.fail('Unexpected output for test:\n  '
+            '${_formatTest(files).replaceAll('\n', '\n  ')}\n'
+            'Expected:\n  ${expected.replaceAll('\n', '\n  ')}\n'
+            'but found:\n  ${found?.replaceAll('\n', '\n  ')}\n'
+            '$regenerateCommand');
+      }
+    }
+  });
+}
+
+String get regenerateCommand {
+  var flags = Platform.packageRoot == null
+    ? '' : '--package-root=${Platform.packageRoot} ';
+  return '''
+If you wish to update the test expectations, rerun this test passing "update" as
+an argument, as follows:
+
+  dart $flags${Platform.script} update
+
+If you want to update more than one test at once, run:
+  dart $flags${Platform.script.resolve('update_all.dart')}
+
+''';
+}
+
+const String TEST_MAIN_FILE = 'test.dart';
+
+String _formatTest(Map test) {
+  return test[TEST_MAIN_FILE];
+}
+
+String _getCodeForMain(CompilerImpl compiler) {
+  Element mainFunction = compiler.mainFunction;
+  js.Node ast = compiler.enqueuer.codegen.generatedCode[mainFunction];
+  return js.prettyPrint(ast, compiler).getText();
+}
+
+String _getCodeForMethod(CompilerImpl compiler,
+                        String name) {
+  Element foundElement;
+  for (Element element in compiler.enqueuer.codegen.generatedCode.keys) {
+    if (element.toString() == name) {
+      if (foundElement != null) {
+        Expect.fail('Multiple compiled elements are called $name');
+      }
+      foundElement = element;
+    }
+  }
+
+  if (foundElement == null) {
+    Expect.fail('There is no compiled element called $name');
+  }
+
+  js.Node ast = compiler.enqueuer.codegen.generatedCode[foundElement];
+  return js.prettyPrint(ast, compiler).getText();
+}