Add '--protocol-traffic-log' option to 'analyze' command. (#78674)

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

@@ -55,6 +55,11 @@ class AnalyzeCommand extends FlutterCommand {
         valueHelp: 'path-to-sdk',
         help: 'The path to the Dart SDK.',
         hide: !verboseHelp);
+    argParser.addOption('protocol-traffic-log',
+        valueHelp: 'path-to-protocol-traffic-log',
+        help: 'The path to write the request and response protocol. This is '
+              'only intended to be used for debugging the tooling.',
+        hide: !verboseHelp);
 
     // Hidden option to enable a benchmarking mode.
     argParser.addFlag('benchmark',

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

@@ -86,6 +86,7 @@ abstract class AnalyzeBase {
   String get sdkPath => argResults['dart-sdk'] as String ?? artifacts.getArtifactPath(Artifact.engineDartSdkPath);
   bool get isBenchmarking => argResults['benchmark'] as bool;
   bool get isDartDocs => argResults['dartdocs'] as bool;
+  String get protocolTrafficLog => argResults['protocol-traffic-log'] as String;
 
   static int countMissingDartDocs(List<AnalysisError> errors) {
     return errors.where((AnalysisError error) {

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

@@ -77,6 +77,7 @@ class AnalyzeContinuously extends AnalyzeBase {
       platform: platform,
       processManager: processManager,
       terminal: terminal,
+      protocolTrafficLog: protocolTrafficLog,
     );
     server.onAnalyzing.listen((bool isAnalyzing) => _handleAnalysisStatus(server, isAnalyzing));
     server.onErrors.listen(_handleAnalysisErrors);

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

@@ -95,6 +95,7 @@ class AnalyzeOnce extends AnalyzeBase {
       logger: logger,
       processManager: processManager,
       terminal: terminal,
+      protocolTrafficLog: protocolTrafficLog,
     );
 
     Stopwatch timer;

packages/flutter_tools/lib/src/dart/analysis.dart

@@ -29,11 +29,13 @@ class AnalysisServer {
     @required Logger logger,
     @required Platform platform,
     @required Terminal terminal,
+    String protocolTrafficLog,
   }) : _fileSystem = fileSystem,
        _processManager = processManager,
        _logger = logger,
        _platform = platform,
-       _terminal = terminal;
+       _terminal = terminal,
+       _protocolTrafficLog = protocolTrafficLog;
 
   final String sdkPath;
   final List<String> directories;
@@ -42,6 +44,7 @@ class AnalysisServer {
   final Logger _logger;
   final Platform _platform;
   final Terminal _terminal;
+  final String _protocolTrafficLog;
 
   Process _process;
   final StreamController<bool> _analyzingController =
@@ -67,6 +70,8 @@ class AnalysisServer {
       '--disable-server-feature-search',
       '--sdk',
       sdkPath,
+      if (_protocolTrafficLog != null)
+        '--protocol-traffic-log=$_protocolTrafficLog',
     ];
 
     _logger.printTrace('dart ${command.skip(1).join(' ')}');