[flutter_tools] allow pulling performance data from assemble (#55699)

packages/flutter_tools/lib/src/build_system/build_system.dart

@@ -666,7 +666,7 @@ class _BuildInstance {
   Future<bool> _invokeInternal(Node node) async {
     final PoolResource resource = await resourcePool.request();
     final Stopwatch stopwatch = Stopwatch()..start();
-    bool passed = true;
+    bool succeeded = true;
     bool skipped = false;
 
     // The build system produces a list of aggregate input and output
@@ -702,7 +702,7 @@ class _BuildInstance {
         skipped = true;
         logger.printTrace('Skipping target: ${node.target.name}');
         updateGraph();
-        return passed;
+        return succeeded;
       }
       logger.printTrace('${node.target.name}: Starting due to ${node.invalidatedReasons}');
       await node.target.build(environment);
@@ -741,7 +741,7 @@ class _BuildInstance {
       // TODO(jonahwilliams): throw specific exception for expected errors to mark
       // as non-fatal. All others should be fatal.
       node.target.clearStamp(environment);
-      passed = false;
+      succeeded = false;
       skipped = false;
       exceptionMeasurements[node.target.name] = ExceptionMeasurement(
           node.target.name, exception, stackTrace);
@@ -752,11 +752,11 @@ class _BuildInstance {
         target: node.target.name,
         elapsedMilliseconds: stopwatch.elapsedMilliseconds,
         skipped: skipped,
-        passed: passed,
+        succeeded: succeeded,
         analyicsName: node.target.analyticsName,
       );
     }
-    return passed;
+    return succeeded;
   }
 }
 
@@ -781,14 +781,14 @@ class PerformanceMeasurement {
     @required this.target,
     @required this.elapsedMilliseconds,
     @required this.skipped,
-    @required this.passed,
+    @required this.succeeded,
     @required this.analyicsName,
   });
 
   final int elapsedMilliseconds;
   final String target;
   final bool skipped;
-  final bool passed;
+  final bool succeeded;
   final String analyicsName;
 }
 

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

@@ -17,6 +17,7 @@ import '../build_system/targets/macos.dart';
 import '../build_system/targets/web.dart';
 import '../build_system/targets/windows.dart';
 import '../cache.dart';
+import '../convert.dart';
 import '../globals.dart' as globals;
 import '../project.dart';
 import '../reporting/reporting.dart';
@@ -72,6 +73,10 @@ class AssembleCommand extends FlutterCommand {
       abbr: 'd',
       help: 'Allows passing configuration to a target with --define=target=key=value.',
     );
+    argParser.addOption(
+      'performance-measurement-file',
+      help: 'Output individual target performance to a JSON file.'
+    );
     argParser.addMultiOption(
       'input',
       abbr: 'i',
@@ -231,6 +236,10 @@ class AssembleCommand extends FlutterCommand {
     if (argResults.wasParsed('build-outputs')) {
       writeListIfChanged(result.outputFiles, stringArg('build-outputs'));
     }
+    if (argResults.wasParsed('performance-measurement-file')) {
+      final File outFile = globals.fs.file(argResults['performance-measurement-file']);
+      writePerformanceData(result.performance.values, outFile);
+    }
     if (argResults.wasParsed('depfile')) {
       final File depfileFile = globals.fs.file(stringArg('depfile'));
       final Depfile depfile = Depfile(result.inputFiles, result.outputFiles);
@@ -262,6 +271,26 @@ void writeListIfChanged(List<File> files, String path) {
   }
 }
 
+/// Output performance measurement data in [outFile].
+@visibleForTesting
+void writePerformanceData(Iterable<PerformanceMeasurement> measurements, File outFile) {
+  final Map<String, Object> jsonData = <String, Object>{
+    'targets': <Object>[
+      for (final PerformanceMeasurement measurement in measurements)
+        <String, Object>{
+          'name': measurement.analyicsName,
+          'skipped': measurement.skipped,
+          'succeeded': measurement.succeeded,
+          'elapsedMilliseconds': measurement.elapsedMilliseconds,
+        }
+    ]
+  };
+  if (!outFile.parent.existsSync()) {
+    outFile.parent.createSync(recursive: true);
+  }
+  outFile.writeAsStringSync(json.encode(jsonData));
+}
+
 class _CompositeTarget extends Target {
   _CompositeTarget(this.dependencies);
 

packages/flutter_tools/test/commands.shard/hermetic/assemble_test.dart

@@ -3,11 +3,14 @@
 // found in the LICENSE file.
 
 import 'package:args/command_runner.dart';
+import 'package:file/memory.dart';
+import 'package:file_testing/file_testing.dart';
 import 'package:flutter_tools/src/artifacts.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
 import 'package:flutter_tools/src/cache.dart';
 import 'package:flutter_tools/src/commands/assemble.dart';
+import 'package:flutter_tools/src/convert.dart';
 import 'package:flutter_tools/src/runner/flutter_command_runner.dart';
 import 'package:mockito/mockito.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
@@ -97,6 +100,37 @@ void main() {
     expect(testLogger.errorText, isNot(contains(testStackTrace.toString())));
   });
 
+  testbed.test('flutter assemble outputs JSON performance data to provided file', () async {
+    when(globals.buildSystem.build(any, any, buildSystemConfig: anyNamed('buildSystemConfig')))
+      .thenAnswer((Invocation invocation) async {
+        return BuildResult(success: true, performance: <String, PerformanceMeasurement>{
+          'hello': PerformanceMeasurement(
+            target: 'hello',
+            analyicsName: 'bar',
+            elapsedMilliseconds: 123,
+            skipped: false,
+            succeeded: true,
+          ),
+        });
+      });
+    final CommandRunner<void> commandRunner = createTestCommandRunner(AssembleCommand());
+
+    await commandRunner.run(<String>[
+      'assemble',
+      '-o Output',
+      '--performance-measurement-file=out.json',
+      'debug_macos_bundle_flutter_assets',
+    ]);
+
+    expect(globals.fs.file('out.json'), exists);
+    expect(
+      json.decode(globals.fs.file('out.json').readAsStringSync()),
+      containsPair('targets', contains(
+        containsPair('name', 'bar'),
+      )),
+    );
+  });
+
   testbed.test('flutter assemble does not inject engine revision with local-engine', () async {
     Environment environment;
     when(globals.artifacts.isLocalEngine).thenReturn(true);
@@ -170,6 +204,36 @@ void main() {
     expect(inputs.readAsStringSync(), contains('fizz'));
     expect(inputs.lastModifiedSync(), isNot(theDistantPast));
   });
+
+  testWithoutContext('writePerformanceData outputs performance data in JSON form', () {
+    final List<PerformanceMeasurement> performanceMeasurement = <PerformanceMeasurement>[
+      PerformanceMeasurement(
+        analyicsName: 'foo',
+        target: 'hidden',
+        skipped: false,
+        succeeded: true,
+        elapsedMilliseconds: 123,
+      )
+    ];
+    final FileSystem fileSystem = MemoryFileSystem.test();
+    final File outFile = fileSystem.currentDirectory
+      .childDirectory('foo')
+      .childFile('out.json');
+
+    writePerformanceData(performanceMeasurement, outFile);
+
+    expect(outFile, exists);
+    expect(json.decode(outFile.readAsStringSync()), <String, Object>{
+      'targets': <Object>[
+        <String, Object>{
+          'name': 'foo',
+          'skipped': false,
+          'succeeded': true,
+          'elapsedMilliseconds': 123,
+        },
+      ],
+    });
+  });
 }
 
 class MockBuildSystem extends Mock implements BuildSystem {}

packages/flutter_tools/test/general.shard/commands/build_aot_test.dart

@@ -119,14 +119,14 @@ void main() {
             analyicsName: 'kernel_snapshot',
             target: 'kernel_snapshot',
             elapsedMilliseconds: 1000,
-            passed: true,
+            succeeded: true,
             skipped: false,
           ),
           'anything': PerformanceMeasurement(
             analyicsName: 'android_aot',
             target: 'anything',
             elapsedMilliseconds: 1000,
-            passed: true,
+            succeeded: true,
             skipped: false,
           ),
         });