Send analytics on 'build ios' and 'build ipa' for plist impeller value (#135193)

This analytics event only records the value of the plist entry on
`build` commands. This will give an idea of the proportion of users who
are disabling Impeller when shipping apps.

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

@@ -20,6 +20,7 @@ import '../globals.dart' as globals;
 import '../ios/application_package.dart';
 import '../ios/mac.dart';
 import '../ios/plist_parser.dart';
+import '../reporting/reporting.dart';
 import '../runner/flutter_command.dart';
 import 'build.dart';
 
@@ -724,6 +725,21 @@ abstract class _BuildIOSSubCommand extends BuildSubCommand {
     if (result.output != null) {
       globals.printStatus('Built ${result.output}.');
 
+      // When an app is successfully built, record to analytics whether Impeller
+      // is enabled or disabled.
+      final BuildableIOSApp app = await buildableIOSApp;
+      final String plistPath = app.project.infoPlist.path;
+      final bool? impellerEnabled = globals.plistParser.getValueFromFile<bool>(
+        plistPath, PlistParser.kFLTEnableImpellerKey,
+      );
+      BuildEvent(
+        impellerEnabled == false
+          ? 'plist-impeller-disabled'
+          : 'plist-impeller-enabled',
+        type: 'ios',
+        flutterUsage: globals.flutterUsage,
+      ).send();
+
       return FlutterCommandResult.success();
     }
 

packages/flutter_tools/lib/src/ios/plist_parser.dart

@@ -31,6 +31,7 @@ class PlistParser {
   static const String kCFBundleVersionKey = 'CFBundleVersion';
   static const String kCFBundleDisplayNameKey = 'CFBundleDisplayName';
   static const String kCFBundleNameKey = 'CFBundleName';
+  static const String kFLTEnableImpellerKey = 'FLTEnableImpeller';
   static const String kMinimumOSVersionKey = 'MinimumOSVersion';
   static const String kNSPrincipalClassKey = 'NSPrincipalClass';
 

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

@@ -17,7 +17,9 @@ import 'package:flutter_tools/src/commands/build.dart';
 import 'package:flutter_tools/src/commands/build_ios.dart';
 import 'package:flutter_tools/src/ios/code_signing.dart';
 import 'package:flutter_tools/src/ios/mac.dart';
+import 'package:flutter_tools/src/ios/plist_parser.dart';
 import 'package:flutter_tools/src/ios/xcodeproj.dart';
+import 'package:flutter_tools/src/project.dart';
 import 'package:flutter_tools/src/reporting/reporting.dart';
 import 'package:test/fake.dart';
 
@@ -438,6 +440,133 @@ void main() {
     Usage: () => usage,
     XcodeProjectInterpreter: () => FakeXcodeProjectInterpreterWithBuildSettings(),
   });
+
+  group('Analytics for impeller plist setting', () {
+    const String plistContents = '''
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+  <key>FLTEnableImpeller</key>
+  <false/>
+</dict>
+</plist>
+''';
+    const FakeCommand plutilCommand = FakeCommand(
+      command: <String>[
+        '/usr/bin/plutil', '-convert', 'xml1', '-o', '-', '/ios/Runner/Info.plist',
+      ],
+      stdout: plistContents,
+    );
+
+    testUsingContext('Sends an analytics event when Impeller is enabled', () async {
+      final BuildCommand command = BuildCommand(
+        androidSdk: FakeAndroidSdk(),
+        buildSystem: TestBuildSystem.all(BuildResult(success: true)),
+        fileSystem: MemoryFileSystem.test(),
+        logger: BufferLogger.test(),
+        osUtils: FakeOperatingSystemUtils(),
+      );
+      createMinimalMockProjectFiles();
+
+      await createTestCommandRunner(command).run(
+        const <String>['build', 'ios', '--no-pub']
+      );
+
+      expect(usage.events, contains(
+        const TestUsageEvent(
+          'build', 'ios',
+          label:'plist-impeller-enabled',
+          parameters:CustomDimensions(),
+        ),
+      ));
+    }, overrides: <Type, Generator>{
+      FileSystem: () => fileSystem,
+      ProcessManager: () => FakeProcessManager.list(<FakeCommand>[
+        xattrCommand,
+        setUpFakeXcodeBuildHandler(onRun: () {
+          fileSystem.directory('build/ios/Release-iphoneos/Runner.app')
+            .createSync(recursive: true);
+        }),
+        setUpRsyncCommand(onRun: () =>
+          fileSystem.file('build/ios/iphoneos/Runner.app/Frameworks/App.framework/App')
+            ..createSync(recursive: true)
+            ..writeAsBytesSync(List<int>.generate(10000, (int index) => 0))),
+      ]),
+      Platform: () => macosPlatform,
+      FileSystemUtils: () => FileSystemUtils(
+        fileSystem: fileSystem,
+        platform: macosPlatform,
+      ),
+      Usage: () => usage,
+      XcodeProjectInterpreter: () => FakeXcodeProjectInterpreterWithBuildSettings(),
+    });
+
+    testUsingContext('Sends an analytics event when Impeller is disabled', () async {
+      final BuildCommand command = BuildCommand(
+        androidSdk: FakeAndroidSdk(),
+        buildSystem: TestBuildSystem.all(BuildResult(success: true)),
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+        osUtils: FakeOperatingSystemUtils(),
+      );
+      createMinimalMockProjectFiles();
+
+      fileSystem.file(
+        fileSystem.path.join('usr', 'bin', 'plutil'),
+      ).createSync(recursive: true);
+
+      final File infoPlist = fileSystem.file(fileSystem.path.join(
+        'ios', 'Runner', 'Info.plist',
+      ))..createSync(recursive: true);
+
+      infoPlist.writeAsStringSync(plistContents);
+
+      await createTestCommandRunner(command).run(
+        const <String>['build', 'ios', '--no-pub']
+      );
+
+      expect(usage.events, contains(
+        const TestUsageEvent(
+          'build', 'ios',
+          label:'plist-impeller-disabled',
+          parameters:CustomDimensions(),
+        ),
+      ));
+    }, overrides: <Type, Generator>{
+      FileSystem: () => fileSystem,
+      ProcessManager: () => FakeProcessManager.list(<FakeCommand>[
+        xattrCommand,
+        setUpFakeXcodeBuildHandler(onRun: () {
+          fileSystem.directory('build/ios/Release-iphoneos/Runner.app')
+            .createSync(recursive: true);
+        }),
+        setUpRsyncCommand(onRun: () =>
+          fileSystem.file('build/ios/iphoneos/Runner.app/Frameworks/App.framework/App')
+            ..createSync(recursive: true)
+            ..writeAsBytesSync(List<int>.generate(10000, (int index) => 0))),
+      ]),
+      Platform: () => macosPlatform,
+      FileSystemUtils: () => FileSystemUtils(
+        fileSystem: fileSystem,
+        platform: macosPlatform,
+      ),
+      Usage: () => usage,
+      XcodeProjectInterpreter: () => FakeXcodeProjectInterpreterWithBuildSettings(),
+      FlutterProjectFactory: () => FlutterProjectFactory(
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+      ),
+      PlistParser: () => PlistParser(
+        fileSystem: fileSystem,
+        logger: BufferLogger.test(),
+        processManager: FakeProcessManager.list(<FakeCommand>[
+          plutilCommand, plutilCommand, plutilCommand,
+        ]),
+      ),
+    });
+  });
+
   group('xcresults device', () {
     testUsingContext('Trace error if xcresult is empty.', () async {
       final BuildCommand command = BuildCommand(

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

@@ -63,7 +63,8 @@ class FakePlistUtils extends Fake implements PlistParser {
 
   @override
   T? getValueFromFile<T>(String plistFilePath, String key) {
-    return fileContents[plistFilePath]![key] as T?;
+    final Map<String, Object>? plistFile = fileContents[plistFilePath];
+    return plistFile == null ? null : plistFile[key] as T?;
   }
 }