Close platform when tests are complete (dispose compiler and delete font files) (#34685)

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

@@ -68,12 +68,14 @@ final Map<InternetAddressType, InternetAddress> _kHosts = <InternetAddressType,
   InternetAddressType.IPv6: InternetAddress.loopbackIPv6,
 };
 
+typedef PlatformPluginRegistration = void Function(FlutterPlatform platform);
+
 /// Configure the `test` package to work with Flutter.
 ///
 /// On systems where each [FlutterPlatform] is only used to run one test suite
 /// (that is, one Dart file with a `*_test.dart` file name and a single `void
 /// main()`), you can set an observatory port explicitly.
-void installHook({
+FlutterPlatform installHook({
   @required String shellPath,
   TestWatcher watcher,
   bool enableObservatory = false,
@@ -91,12 +93,20 @@ void installHook({
   Uri projectRootDirectory,
   FlutterProject flutterProject,
   String icudtlPath,
+  PlatformPluginRegistration platformPluginRegistration
 }) {
   assert(enableObservatory || (!startPaused && observatoryPort == null));
+
+  // registerPlatformPlugin can be injected for testing since it's not very mock-friendly.
+  platformPluginRegistration ??= (FlutterPlatform platform) {
     hack.registerPlatformPlugin(
       <Runtime>[Runtime.vm],
         () {
-      return FlutterPlatform(
+        return platform;
+      }
+    );
+  };
+  final FlutterPlatform platform = FlutterPlatform(
     shellPath: shellPath,
     watcher: watcher,
     machine: machine,
@@ -115,8 +125,8 @@ void installHook({
     flutterProject: flutterProject,
     icudtlPath: icudtlPath,
   );
-    }
-  );
+  platformPluginRegistration(platform);
+  return platform;
 }
 
 /// Generates the bootstrap entry point script that will be used to launch an

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

@@ -105,7 +105,7 @@ Future<int> runTests(
   final InternetAddressType serverType =
       ipv6 ? InternetAddressType.IPv6 : InternetAddressType.IPv4;
 
-  loader.installHook(
+  final loader.FlutterPlatform platform = loader.installHook(
     shellPath: shellPath,
     watcher: watcher,
     enableObservatory: enableObservatory,
@@ -145,5 +145,6 @@ Future<int> runTests(
     return exitCode;
   } finally {
     fs.currentDirectory = saved;
+    await platform.close();
   }
 }

packages/flutter_tools/test/flutter_platform_test.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:flutter_tools/src/base/common.dart';
+import 'package:flutter_tools/src/base/io.dart';
 import 'package:flutter_tools/src/test/flutter_platform.dart';
 
 import 'package:mockito/mockito.dart';
@@ -24,6 +25,58 @@ void main() {
       flutterPlatfrom.loadChannel('test1.dart', MockPlatform());
       expect(() => flutterPlatfrom.loadChannel('test2.dart', MockPlatform()), throwsA(isA<ToolExit>()));
     });
+
+    testUsingContext('installHook creates a FlutterPlatform', () {
+      expect(() => installHook(
+        shellPath: 'abc',
+        enableObservatory: false,
+        startPaused: true
+      ), throwsA(isA<AssertionError>()));
+
+      expect(() => installHook(
+        shellPath: 'abc',
+        enableObservatory: false,
+        startPaused: false,
+        observatoryPort: 123
+      ), throwsA(isA<AssertionError>()));
+
+      FlutterPlatform capturedPlatform;
+      final Map<String, String> expectedPrecompiledDillFiles = <String, String>{'Key': 'Value'};
+      final FlutterPlatform flutterPlatform = installHook(
+        shellPath: 'abc',
+        enableObservatory: true,
+        machine: true,
+        startPaused: true,
+        disableServiceAuthCodes: true,
+        port: 100,
+        precompiledDillPath: 'def',
+        precompiledDillFiles: expectedPrecompiledDillFiles,
+        trackWidgetCreation: true,
+        updateGoldens: true,
+        buildTestAssets: true,
+        observatoryPort: 200,
+        serverType: InternetAddressType.IPv6,
+        icudtlPath: 'ghi',
+        platformPluginRegistration: (FlutterPlatform platform) {
+          capturedPlatform = platform;
+        });
+
+      expect(identical(capturedPlatform, flutterPlatform), equals(true));
+      expect(flutterPlatform.shellPath, equals('abc'));
+      expect(flutterPlatform.enableObservatory, equals(true));
+      expect(flutterPlatform.machine, equals(true));
+      expect(flutterPlatform.startPaused, equals(true));
+      expect(flutterPlatform.disableServiceAuthCodes, equals(true));
+      expect(flutterPlatform.port, equals(100));
+      expect(flutterPlatform.host, InternetAddress.loopbackIPv6);
+      expect(flutterPlatform.explicitObservatoryPort, equals(200));
+      expect(flutterPlatform.precompiledDillPath, equals('def'));
+      expect(flutterPlatform.precompiledDillFiles, expectedPrecompiledDillFiles);
+      expect(flutterPlatform.trackWidgetCreation, equals(true));
+      expect(flutterPlatform.updateGoldens, equals(true));
+      expect(flutterPlatform.buildTestAssets, equals(true));
+      expect(flutterPlatform.icudtlPath, equals('ghi'));
+    });
   });
 }