Update fuchsia-tester so it takes map of kernel test files (#21573)

* Update fuchsia-tester so it takes map of kernel test files

* Set mainDart correctly. Cleanup nits.

packages/flutter_tools/bin/fuchsia_tester.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
+import 'dart:convert' show json;
 import 'dart:math' as math;
 
 import 'package:args/args.dart';
@@ -27,17 +28,15 @@ const String _kOptionPackages = 'packages';
 const String _kOptionShell = 'shell';
 const String _kOptionTestDirectory = 'test-directory';
 const String _kOptionSdkRoot = 'sdk-root';
-const String _kOptionTestFile = 'test-file';
-const String _kOptionDillFile = 'dill-file';
 const String _kOptionIcudtl = 'icudtl';
+const String _kOptionTests = 'tests';
 const List<String> _kRequiredOptions = <String>[
   _kOptionPackages,
   _kOptionShell,
   _kOptionTestDirectory,
   _kOptionSdkRoot,
-  _kOptionTestFile,
-  _kOptionDillFile,
-  _kOptionIcudtl
+  _kOptionIcudtl,
+  _kOptionTests,
 ];
 const String _kOptionCoverage = 'coverage';
 const String _kOptionCoveragePath = 'coverage-path';
@@ -54,9 +53,8 @@ Future<Null> run(List<String> args) async {
     ..addOption(_kOptionShell, help: 'The Flutter shell binary')
     ..addOption(_kOptionTestDirectory, help: 'Directory containing the tests')
     ..addOption(_kOptionSdkRoot, help: 'Path to the SDK platform files')
-    ..addOption(_kOptionTestFile, help: 'Test file to execute')
-    ..addOption(_kOptionDillFile, help: 'Precompiled dill file for test')
     ..addOption(_kOptionIcudtl, help: 'Path to the ICU data file')
+    ..addOption(_kOptionTests, help: 'Path to json file that maps Dart test files to precompiled dill files')
     ..addFlag(_kOptionCoverage,
       defaultsTo: false,
       negatable: false,
@@ -77,8 +75,6 @@ Future<Null> run(List<String> args) async {
     Cache.flutterRoot = tempDir.path;
     final Directory testDirectory =
         fs.directory(argResults[_kOptionTestDirectory]);
-    final File testFile = fs.file(argResults[_kOptionTestFile]);
-    final File dillFile = fs.file(argResults[_kOptionDillFile]);
 
     final String shellPath = argResults[_kOptionShell];
     if (!fs.isFileSync(shellPath)) {
@@ -115,13 +111,21 @@ Future<Null> run(List<String> args) async {
       collector = new CoverageCollector();
     }
 
+
+    final Map<String, String> tests = <String, String>{};
+    final List<Map<String, dynamic>> jsonList = List<Map<String, dynamic>>.from(
+      json.decode(fs.file(argResults[_kOptionTests]).readAsStringSync()));
+    for (Map<String, dynamic> map in jsonList) {
+      tests[map['source']] = map['dill'];
+    }
+
     exitCode = await runTests(
-      <String>[testFile.path],
+      tests.keys.toList(),
       workDir: testDirectory,
       watcher: collector,
       ipv6: false,
       enableObservatory: collector != null,
-      precompiledDillPath: dillFile.path,
+      precompiledDillFiles: tests,
       concurrency: math.max(1, platform.numberOfProcessors - 2),
     );
 

packages/flutter_tools/lib/src/test/flutter_platform.dart

@@ -70,6 +70,7 @@ void installHook({
   bool startPaused = false,
   int port = 0,
   String precompiledDillPath,
+  Map<String, String> precompiledDillFiles,
   bool trackWidgetCreation = false,
   bool updateGoldens = false,
   int observatoryPort,
@@ -89,6 +90,7 @@ void installHook({
       host: _kHosts[serverType],
       port: port,
       precompiledDillPath: precompiledDillPath,
+      precompiledDillFiles: precompiledDillFiles,
       trackWidgetCreation: trackWidgetCreation,
       updateGoldens: updateGoldens,
       projectRootDirectory: projectRootDirectory,
@@ -339,6 +341,7 @@ class _FlutterPlatform extends PlatformPlugin {
     this.host,
     this.port,
     this.precompiledDillPath,
+    this.precompiledDillFiles,
     this.trackWidgetCreation,
     this.updateGoldens,
     this.projectRootDirectory,
@@ -353,6 +356,7 @@ class _FlutterPlatform extends PlatformPlugin {
   final InternetAddress host;
   final int port;
   final String precompiledDillPath;
+  final Map<String, String> precompiledDillFiles;
   final bool trackWidgetCreation;
   final bool updateGoldens;
   final Uri projectRootDirectory;
@@ -444,12 +448,17 @@ class _FlutterPlatform extends PlatformPlugin {
       printTrace('test $ourTestCount: starting shell process');
 
       // If a kernel file is given, then use that to launch the test.
-      // Otherwise create a "listener" dart that invokes actual test.
-      String mainDart = precompiledDillPath != null
-          ? precompiledDillPath
-          : _createListenerDart(finalizers, ourTestCount, testPath, server);
+      // If mapping is provided, look kernel file from mapping.
+      // If all fails, create a "listener" dart that invokes actual test.
+      String mainDart;
+      if (precompiledDillPath != null) {
+        mainDart = precompiledDillPath;
+      } else if (precompiledDillFiles != null) {
+        mainDart = precompiledDillFiles[testPath];
+      }
+      mainDart ??= _createListenerDart(finalizers, ourTestCount, testPath, server);
 
-      if (precompiledDillPath == null) {
+      if (precompiledDillPath == null && precompiledDillFiles == null) {
         // Lazily instantiate compiler so it is built only if it is actually used.
         compiler ??= new _Compiler(trackWidgetCreation, projectRootDirectory);
         mainDart = await compiler.compile(mainDart);

packages/flutter_tools/lib/src/test/runner.dart

@@ -29,6 +29,7 @@ Future<int> runTests(
   bool ipv6 = false,
   bool machine = false,
   String precompiledDillPath,
+  Map<String, String> precompiledDillFiles,
   bool trackWidgetCreation = false,
   bool updateGoldens = false,
   TestWatcher watcher,
@@ -75,6 +76,7 @@ Future<int> runTests(
     startPaused: startPaused,
     serverType: serverType,
     precompiledDillPath: precompiledDillPath,
+    precompiledDillFiles: precompiledDillFiles,
     trackWidgetCreation: trackWidgetCreation,
     updateGoldens: updateGoldens,
     projectRootDirectory: fs.currentDirectory.uri,