add testing to screenshot and printDetails method (#36418)

packages/flutter_tools/lib/src/resident_runner.dart

@@ -679,7 +679,14 @@ abstract class ResidentRunner {
     }
   }
 
+  /// Take a screenshot on the provided [device].
+  ///
+  /// If the device has a connected vmservice, this method will attempt to hide
+  /// and restore the debug banner before taking the screenshot.
+  ///
+  /// Throws an [AssertionError] if [Devce.supportsScreenshot] is not true.
   Future<void> screenshot(FlutterDevice device) async {
+    assert(device.device.supportsScreenshot);
     final Status status = logger.startProgress('Taking screenshot for ${device.device.name}...', timeout: timeoutConfiguration.fastOperation);
     final File outputFile = getUniqueFile(fs.currentDirectory, 'flutter', 'png');
     try {

packages/flutter_tools/test/general.shard/resident_runner_test.dart

@@ -5,6 +5,9 @@
 import 'dart:async';
 
 import 'package:flutter_tools/src/base/common.dart';
+import 'package:flutter_tools/src/base/context.dart';
+import 'package:flutter_tools/src/base/file_system.dart';
+import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/devfs.dart';
 import 'package:flutter_tools/src/device.dart';
@@ -19,7 +22,6 @@ import '../src/common.dart';
 import '../src/testbed.dart';
 
 void main() {
-  group('ResidentRunner', () {
   final Uri testUri = Uri.parse('foo://bar');
   Testbed testbed;
   MockFlutterDevice mockFlutterDevice;
@@ -107,7 +109,7 @@ void main() {
     });
   });
 
-    test('Can attach to device successfully', () => testbed.run(() async {
+  test('ResidentRunner can attach to device successfully', () => testbed.run(() async {
     final Completer<DebugConnectionInfo> onConnectionInfo = Completer<DebugConnectionInfo>.sync();
     final Completer<void> onAppStart = Completer<void>.sync();
     final Future<int> result = residentRunner.attach(
@@ -125,7 +127,7 @@ void main() {
     expect(onAppStart.isCompleted, true);
   }));
 
-    test('Can handle an RPC exception from hot reload', () => testbed.run(() async {
+  test('ResidentRunner can handle an RPC exception from hot reload', () => testbed.run(() async {
     when(mockDevice.sdkNameAndVersion).thenAnswer((Invocation invocation) async {
       return 'Example';
     });
@@ -168,7 +170,7 @@ void main() {
     Usage: () => MockUsage(),
   }));
 
-    test('Can handle an RPC exception from hot restart', () => testbed.run(() async {
+  test('ResidentRunner Can handle an RPC exception from hot restart', () => testbed.run(() async {
     when(mockDevice.sdkNameAndVersion).thenAnswer((Invocation invocation) async {
       return 'Example';
     });
@@ -212,8 +214,113 @@ void main() {
     Usage: () => MockUsage(),
   }));
 
-    group('FlutterDevice' , () {
-      test('Will not exit a paused isolate', () => testbed.run(() async {
+  test('ResidentRunner printHelpDetails', () => testbed.run(() {
+    when(mockDevice.supportsHotRestart).thenReturn(true);
+    when(mockDevice.supportsScreenshot).thenReturn(true);
+
+    residentRunner.printHelp(details: true);
+    final BufferLogger bufferLogger = context.get<Logger>();
+
+    // supports service protocol
+    expect(residentRunner.supportsServiceProtocol, true);
+    expect(bufferLogger.statusText, contains('"w"'));
+    expect(bufferLogger.statusText, contains('"t"'));
+    expect(bufferLogger.statusText, contains('"P"'));
+    expect(bufferLogger.statusText, contains('"a"'));
+    // isRunningDebug
+    expect(residentRunner.isRunningDebug, true);
+    expect(bufferLogger.statusText, contains('"L"'));
+    expect(bufferLogger.statusText, contains('"S"'));
+    expect(bufferLogger.statusText, contains('"U"'));
+    expect(bufferLogger.statusText, contains('"i"'));
+    expect(bufferLogger.statusText, contains('"p"'));
+    expect(bufferLogger.statusText, contains('"o"'));
+    expect(bufferLogger.statusText, contains('"z"'));
+    // screenshot
+    expect(bufferLogger.statusText, contains('"s"'));
+  }));
+
+  test('ResidentRunner can take screenshot on debug device', () => testbed.run(() async {
+    when(mockDevice.supportsScreenshot).thenReturn(true);
+    when(mockDevice.takeScreenshot(any))
+        .thenAnswer((Invocation invocation) async {
+      final File file = invocation.positionalArguments.first;
+      file.writeAsBytesSync(List<int>.generate(1024, (int i) => i));
+    });
+    final BufferLogger bufferLogger = context.get<Logger>();
+
+    await residentRunner.screenshot(mockFlutterDevice);
+
+    // disables debug banner.
+    verify(mockIsolate.flutterDebugAllowBanner(false)).called(1);
+    // Enables debug banner.
+    verify(mockIsolate.flutterDebugAllowBanner(true)).called(1);
+    expect(bufferLogger.statusText, contains('1kB'));
+  }));
+
+  test('ResidentRunner bails taking screenshot on debug device if debugAllowBanner throws pre', () => testbed.run(() async {
+    when(mockDevice.supportsScreenshot).thenReturn(true);
+    when(mockIsolate.flutterDebugAllowBanner(false)).thenThrow(Exception());
+    final BufferLogger bufferLogger = context.get<Logger>();
+
+    await residentRunner.screenshot(mockFlutterDevice);
+
+    expect(bufferLogger.errorText, contains('Error'));
+  }));
+
+  test('ResidentRunner bails taking screenshot on debug device if debugAllowBanner throws post', () => testbed.run(() async {
+    when(mockDevice.supportsScreenshot).thenReturn(true);
+    when(mockIsolate.flutterDebugAllowBanner(true)).thenThrow(Exception());
+    final BufferLogger bufferLogger = context.get<Logger>();
+
+    await residentRunner.screenshot(mockFlutterDevice);
+
+    expect(bufferLogger.errorText, contains('Error'));
+  }));
+
+  test('ResidentRunner bails taking screenshot on debug device if takeScreenshot throws', () => testbed.run(() async {
+    when(mockDevice.supportsScreenshot).thenReturn(true);
+    when(mockDevice.takeScreenshot(any)).thenThrow(Exception());
+    final BufferLogger bufferLogger = context.get<Logger>();
+
+    await residentRunner.screenshot(mockFlutterDevice);
+
+    expect(bufferLogger.errorText, contains('Error'));
+  }));
+
+  test('ResidentRunner can\'t take screenshot on device without support', () => testbed.run(() {
+    when(mockDevice.supportsScreenshot).thenReturn(false);
+
+    expect(() => residentRunner.screenshot(mockFlutterDevice),
+        throwsA(isInstanceOf<AssertionError>()));
+  }));
+
+  test('ResidentRunner does not toggle banner in non-debug mode', () => testbed.run(() async {
+    residentRunner = HotRunner(
+      <FlutterDevice>[
+        mockFlutterDevice,
+      ],
+      stayResident: false,
+      debuggingOptions: DebuggingOptions.disabled(BuildInfo.release),
+    );
+    when(mockDevice.supportsScreenshot).thenReturn(true);
+    when(mockDevice.takeScreenshot(any))
+        .thenAnswer((Invocation invocation) async {
+      final File file = invocation.positionalArguments.first;
+      file.writeAsBytesSync(List<int>.generate(1024, (int i) => i));
+    });
+    final BufferLogger bufferLogger = context.get<Logger>();
+
+    await residentRunner.screenshot(mockFlutterDevice);
+
+    // doesn't disabled debug banner.
+    verifyNever(mockIsolate.flutterDebugAllowBanner(false));
+    // doesn't enable debug banner.
+    verifyNever(mockIsolate.flutterDebugAllowBanner(true));
+    expect(bufferLogger.statusText, contains('1kB'));
+  }));
+
+  test('FlutterDevice will not exit a paused isolate', () => testbed.run(() async {
     final TestFlutterDevice flutterDevice = TestFlutterDevice(
       mockDevice,
       <FlutterView>[ mockFlutterView ],
@@ -229,7 +336,7 @@ void main() {
     verify(mockDevice.stopApp(any)).called(1);
   }));
 
-      test('Will exit an un-paused isolate', () => testbed.run(() async {
+  test('FlutterDevice will exit an un-paused isolate', () => testbed.run(() async {
     final TestFlutterDevice flutterDevice = TestFlutterDevice(
       mockDevice,
       <FlutterView> [mockFlutterView ],
@@ -244,8 +351,6 @@ void main() {
 
     verify(mockIsolate.flutterExit()).called(1);
   }));
-    });
-  });
 }
 
 class MockFlutterDevice extends Mock implements FlutterDevice {}