first cut fuzz test for analysis server

pkg/analysis_server/bin/fuzz.dart

Index: pkg/analysis_server/bin/fuzz.dart
diff --git a/pkg/analysis_server/bin/fuzz.dart b/pkg/analysis_server/bin/fuzz.dart
new file mode 100644
index 0000000000000000000000000000000000000000..8fc71d997bf51a221d91ea65c09d511fc48c29ec
--- /dev/null
+++ b/pkg/analysis_server/bin/fuzz.dart
@@ -0,0 +1,166 @@
+// Copyright (c) 2014, 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.
+
+import 'dart:async';
+import 'dart:io';
+
+import 'package:args/args.dart';
+import 'package:matcher/matcher.dart';
+import 'package:path/path.dart' as path;
+
+import 'fuzz/server_manager.dart';
+
+/**
+ * Start analysis server as a separate process and use the stdio to communicate
+ * with the server.
+ */
+void main(List<String> args) {
+  new _FuzzTest().run(args);
+}
+
+/**
+ * Instances of [_FuzzTest] launch and test an analysis server.
+ * You must specify the location of the Dart SDK and the directory
+ * containing sources to be analyzed.
+ */
+class _FuzzTest {
+
+  //TODO (danrubel) extract common behavior for use in multiple test scenarios
+  //TODO (danrubel) cleanup test to use async/await for better readability
+  // VM flag --enable_async
+
+  static const String DART_SDK_OPTION = 'dart-sdk';
+  static const String HELP_OPTION = 'help';
+
+  File serverSnapshot;
+  Directory appDir;
+
+  /// Parse the arguments and initialize the receiver
+  /// Return `true` if proper arguments were provided
+  bool parseArgs(List<String> args) {
+    ArgParser parser = new ArgParser();
+
+    void error(String errMsg) {
+      stderr.writeln(errMsg);
+      print('');
+      _printUsage(parser);
+      exitCode = 11;
+    }
+
+    parser.addOption(DART_SDK_OPTION, help: '[sdkPath] path to Dart SDK');
+    parser.addFlag(
+        HELP_OPTION,
+        help: 'print this help message without starting analysis',
+        defaultsTo: false,
+        negatable: false);
+
+    ArgResults results;
+    try {
+      results = parser.parse(args);
+    } on FormatException catch (e) {
+      error(e.message);
+      return false;
+    }
+    if (results[HELP_OPTION]) {
+      _printUsage(parser);
+      return false;
+    }
+    String sdkPath = results[DART_SDK_OPTION];
+    if (sdkPath is! String) {
+      error('Missing path to Dart SDK');
+      return false;
+    }
+    Directory sdkDir = new Directory(sdkPath);
+    if (!sdkDir.existsSync()) {
+      error('Specified Dart SDK does not exist: $sdkPath');
+      return false;
+    }
+    if (results.rest.length == 0) {
+      error('Expected directory to analyze');
+      return false;
+    }
+    appDir = new Directory(results.rest[0]);
+    if (!appDir.existsSync()) {
+      error('Specified application directory does not exist: $appDir');
+      return false;
+    }
+    if (results.rest.length > 1) {
+      error('Unexpected arguments after $appDir');
+      return false;
+    }
+    serverSnapshot = new File(
+        path.join(sdkDir.path, 'bin', 'snapshots', 'analysis_server.dart.snapshot'));
+    if (!serverSnapshot.existsSync()) {
+      error('Analysis Server snapshot not found: $serverSnapshot');
+      return false;
+    }
+    return true;
+  }
+
+  /// Main entry point for launching, testing, and shutting down the server
+  void run(List<String> args) {
+    if (!parseArgs(args)) return;
+    ServerManager.start(serverSnapshot.path).then((ServerManager manager) {
+      runZoned(() {
+        test(manager).then(manager.stop).then((_) {
+          expect(manager.errorOccurred, isFalse);
+          print('Test completed successfully');
+        });
+      }, onError: (error, stack) {
+        stderr.writeln(error);
+        print(stack);
+        exitCode = 12;
+        manager.stop();
+      });
+    });
+  }
+
+  /// Use manager to exercise the analysis server
+  Future test(ServerManager manager) {
+
+    // perform initial analysis
+    return manager.analyze(appDir).then((AnalysisResults analysisResults) {
+      print(
+          'Found ${analysisResults.errorCount} errors,'
+              ' ${analysisResults.warningCount} warnings,'
+              ' and ${analysisResults.hintCount} hints in ${analysisResults.elapsed}');
+
+      // edit a method body
+      return manager.openFileNamed(
+          'domain_completion.dart').then((Editor editor) {
+        return editor.moveAfter('Response processRequest(Request request) {');
+      }).then((Editor editor) {
+        return editor.replace(0, '\nOb');
+      }).then((Editor editor) {
+
+        // request code completion and assert results
+        return editor.getSuggestions().then((List<CompletionResults> list) {
+          expect(list, isNotNull);
+          expect(list.length, equals(0));
+          list.forEach((CompletionResults results) {
+            print('${results.elapsed} received ${results.suggestionCount} suggestions');
+          });
+          return editor;
+        });
+
+      }).then((Editor editor) {
+        print('tests complete');
+      });
+    });
+  }
+
+  void _printAnalysisSummary(AnalysisResults results) {
+    print(
+        'Found ${results.errorCount} errors, ${results.warningCount} warnings,'
+            ' and ${results.hintCount} hints in $results.elapsed');
+  }
+
+  /// Print information about how to use the server.
+  void _printUsage(ArgParser parser) {
+    print('Usage: analyzer [flags] <application_directory>');
+    print('');
+    print('Supported flags are:');
+    print(parser.getUsage());
+  }
+}