have flutter analyze support --preview-dart-2 (#14582)

* have flutter analyze support --preview-dart-2

* review comments

packages/flutter_tools/lib/src/commands/analyze.dart

@@ -19,6 +19,7 @@ class AnalyzeCommand extends FlutterCommand {
     argParser.addFlag('current-package', help: 'Include the lib/main.dart file from the current directory, if any.', defaultsTo: true);
     argParser.addFlag('dartdocs', help: 'List every public member that is lacking documentation (only works with --flutter-repo and without --watch).', defaultsTo: false, hide: !verboseHelp);
     argParser.addFlag('watch', help: 'Run analysis continuously, watching the filesystem for changes.', negatable: false);
+    argParser.addFlag('preview-dart-2', help: 'Preview Dart 2.0 functionality.');
     argParser.addOption('write', valueHelp: 'file', help: 'Also output the results to a file. This is useful with --watch if you want a file to always contain the latest results.');
     argParser.addOption('dart-sdk', valueHelp: 'path-to-sdk', help: 'The path to the Dart SDK.', hide: !verboseHelp);
 
@@ -57,9 +58,16 @@ class AnalyzeCommand extends FlutterCommand {
   @override
   Future<Null> runCommand() {
     if (argResults['watch']) {
-      return new AnalyzeContinuously(argResults, runner.getRepoPackages()).analyze();
+      return new AnalyzeContinuously(
+        argResults, runner.getRepoPackages(), previewDart2: argResults['preview-dart-2']
+      ).analyze();
     } else {
-      return new AnalyzeOnce(argResults, runner.getRepoPackages(), workingDirectory: workingDirectory).analyze();
+      return new AnalyzeOnce(
+        argResults,
+        runner.getRepoPackages(),
+        workingDirectory: workingDirectory,
+        previewDart2: argResults['preview-dart-2'],
+      ).analyze();
     }
   }
 }

packages/flutter_tools/lib/src/commands/analyze_continuously.dart

@@ -20,9 +20,10 @@ import '../globals.dart';
 import 'analyze_base.dart';
 
 class AnalyzeContinuously extends AnalyzeBase {
-  AnalyzeContinuously(ArgResults argResults, this.repoPackages) : super(argResults);
+  AnalyzeContinuously(ArgResults argResults, this.repoPackages, { this.previewDart2: false }) : super(argResults);
 
   final List<Directory> repoPackages;
+  final bool previewDart2;
 
   String analysisTarget;
   bool firstAnalysis = true;
@@ -52,7 +53,7 @@ class AnalyzeContinuously extends AnalyzeBase {
       analysisTarget = fs.currentDirectory.path;
     }
 
-    final AnalysisServer server = new AnalysisServer(dartSdkPath, directories);
+    final AnalysisServer server = new AnalysisServer(dartSdkPath, directories, previewDart2: previewDart2);
     server.onAnalyzing.listen((bool isAnalyzing) => _handleAnalysisStatus(server, isAnalyzing));
     server.onErrors.listen(_handleAnalysisErrors);
 
@@ -150,10 +151,11 @@ class AnalyzeContinuously extends AnalyzeBase {
 }
 
 class AnalysisServer {
-  AnalysisServer(this.sdk, this.directories);
+  AnalysisServer(this.sdk, this.directories, { this.previewDart2: false });
 
   final String sdk;
   final List<String> directories;
+  final bool previewDart2;
 
   Process _process;
   final StreamController<bool> _analyzingController = new StreamController<bool>.broadcast();
@@ -170,6 +172,10 @@ class AnalysisServer {
       sdk,
     ];
 
+    if (previewDart2) {
+      command.add('--preview-dart-2');
+    }
+
     printTrace('dart ${command.skip(1).join(' ')}');
     _process = await processManager.start(command);
     // This callback hookup can't throw.

packages/flutter_tools/lib/src/commands/analyze_once.dart

@@ -23,13 +23,18 @@ typedef bool FileFilter(FileSystemEntity entity);
 
 /// An aspect of the [AnalyzeCommand] to perform once time analysis.
 class AnalyzeOnce extends AnalyzeBase {
-  AnalyzeOnce(ArgResults argResults, this.repoPackages, { this.workingDirectory }) : super(argResults);
+  AnalyzeOnce(ArgResults argResults, this.repoPackages, {
+    this.workingDirectory,
+    this.previewDart2: false,
+  }) : super(argResults);
 
   final List<Directory> repoPackages;
 
   /// The working directory for testing analysis using dartanalyzer
   final Directory workingDirectory;
 
+  final bool previewDart2;
+
   @override
   Future<Null> analyze() async {
     final Stopwatch stopwatch = new Stopwatch()..start();
@@ -82,6 +87,10 @@ class AnalyzeOnce extends AnalyzeBase {
         arguments.insert(1, packagesFile.path);
       }
 
+      if (previewDart2) {
+        arguments.add('--preview-dart-2');
+      }
+
       final String dartanalyzer = fs.path.join(Cache.flutterRoot, 'bin', 'cache', 'dart-sdk', 'bin', 'dartanalyzer');
       arguments.insert(0, dartanalyzer);
       bool noErrors = false;

packages/flutter_tools/test/commands/analyze_continuously_test.dart

@@ -69,6 +69,44 @@ void main() {
   }, overrides: <Type, Generator>{
     OperatingSystemUtils: () => os
   });
+
+  testUsingContext('--preview-dart-2', () async {
+    final String contents = "StringBuffer bar = StringBuffer('baz');";
+    tempDir.childFile('main.dart').writeAsStringSync(contents);
+    server = new AnalysisServer(dartSdkPath, <String>[tempDir.path], previewDart2: true);
+
+    int errorCount = 0;
+    final Future<bool> onDone = server.onAnalyzing.where((bool analyzing) => analyzing == false).first;
+    server.onErrors.listen((FileAnalysisErrors errors) {
+      errorCount += errors.errors.length;
+    });
+
+    await server.start();
+    await onDone;
+
+    expect(errorCount, 0);
+  }, overrides: <Type, Generator>{
+    OperatingSystemUtils: () => os
+  });
+
+  testUsingContext('no --preview-dart-2 shows errors', () async {
+    final String contents = "StringBuffer bar = StringBuffer('baz');";
+    tempDir.childFile('main.dart').writeAsStringSync(contents);
+    server = new AnalysisServer(dartSdkPath, <String>[tempDir.path], previewDart2: false);
+
+    int errorCount = 0;
+    final Future<bool> onDone = server.onAnalyzing.where((bool analyzing) => analyzing == false).first;
+    server.onErrors.listen((FileAnalysisErrors errors) {
+      errorCount += errors.errors.length;
+    });
+
+    await server.start();
+    await onDone;
+
+    expect(errorCount, 1);
+  }, overrides: <Type, Generator>{
+    OperatingSystemUtils: () => os
+  });
 }
 
 void _createSampleProject(Directory directory, { bool brokenCode: false }) {

packages/flutter_tools/test/commands/analyze_once_test.dart

@@ -192,6 +192,45 @@ void bar() {
         toolExit: true,
       );
     });
+
+    testUsingContext('--preview-dart-2', () async {
+      final String contents = '''
+StringBuffer bar = StringBuffer('baz');
+''';
+
+      final Directory tempDir = fs.systemTempDirectory.createTempSync();
+      tempDir.childFile('main.dart').writeAsStringSync(contents);
+
+      try {
+        await runCommand(
+          command: new AnalyzeCommand(workingDirectory: fs.directory(tempDir)),
+          arguments: <String>['analyze', '--preview-dart-2'],
+          statusTextContains: <String>['No issues found!'],
+        );
+      } finally {
+        tempDir.deleteSync(recursive: true);
+      }
+    });
+
+    testUsingContext('no --preview-dart-2 shows errors', () async {
+      final String contents = '''
+StringBuffer bar = StringBuffer('baz');
+''';
+
+      final Directory tempDir = fs.systemTempDirectory.createTempSync();
+      tempDir.childFile('main.dart').writeAsStringSync(contents);
+
+      try {
+        await runCommand(
+          command: new AnalyzeCommand(workingDirectory: fs.directory(tempDir)),
+          arguments: <String>['analyze'],
+          statusTextContains: <String>['1 issue found.'],
+          toolExit: true,
+        );
+      } finally {
+        tempDir.deleteSync(recursive: true);
+      }
+    });
   });
 }