[tool] Define modular dependency injection containers and bootstrapper by bkonyi · Pull Request #190724 · flutter/flutter

bkonyi · 2026-08-07T18:06:58Z

Summary

Part 1 of the modular dependency injection migration.

Defines the foundational modular dependency injection containers and bootstrapper for flutter_tools:

ToolContext: Layer 1 OS wrappers (HostEnvironment) and Layer 2 SDK state (ToolConfiguration).
Nullable Sub-contexts: AndroidContext and AppleContext for clean platform isolation.
ToolDependencies: Topologically instantiates and manages the dependency graph at startup with explicit overrides and lazy closures.
Hermetic Test Doubles: Includes dependency_injection_test.dart and fake context doubles.

Followed by Part 2 (#190922) for runner wiring.

Part of #47161

gemini-code-assist

Code Review

This pull request introduces a structured dependency injection and context bootstrapping mechanism for flutter_tools by adding AndroidContext, AppleContext, ToolContext, and a central ToolDependencies bootstrapper, along with corresponding tests and fakes. Feedback on the implementation highlights that tool_dependencies.dart should use the resolved finalShutdownHooks and finalSystemClock.now() to maintain a single source of truth and ensure hermetic time-dependent behavior. Additionally, the fake context classes in fakes.dart should be refactored to use late final fields instead of returning new instances on every getter invocation, preserving state persistence and referential transparency in tests.

gemini-code-assist · 2026-08-11T17:09:18Z

+            delegate: LocalFileSystem(
+              LocalSignals.instance,
+              Signals.defaultExitSignals,
+              shutdownHooks ?? ShutdownHooks(),


A new ShutdownHooks instance is created here if shutdownHooks is null, instead of using the already resolved finalShutdownHooks defined on line 136. This breaks the single source of truth for shutdown hooks, meaning any hooks registered on finalShutdownHooks won't be coordinated with the LocalFileSystem's shutdown hooks.

Suggested change

shutdownHooks ?? ShutdownHooks(),

finalShutdownHooks,

References

Avoid duplicating state: Keep only one source of truth. ^(link)

Done. Addressed in commit 341b711.

gemini-code-assist · 2026-08-11T17:09:18Z

+  @override
+  Artifacts get artifacts => _artifacts ?? FakeArtifacts(fileSystem: fs);
+
+  @override
+  BotDetector get botDetector => _botDetector ?? const FakeBotDetector(false);
+
+  @override
+  Cache get cache => _cache ?? FakeCache(fileSystem: fs);
+
+  @override
+  Config get config => _config ?? FakeConfig();
+
+  @override
+  CustomDevicesConfig get customDevicesConfig =>
+      _customDevicesConfig ??
+      CustomDevicesConfig.test(fileSystem: fs, logger: logger, platform: platform);
+
+  @override
+  FlutterVersion get flutterVersion => _flutterVersion ?? FakeFlutterVersion();
+
+  @override
+  FileSystem get fs => _fs ?? MemoryFileSystem.test();
+
+  @override
+  Git get git => _git ?? Git(currentPlatform: platform, runProcessWith: processUtils);
+
+  @override
+  LocalEngineLocator get localEngineLocator =>
+      _localEngineLocator ??
+      LocalEngineLocator(
+        userMessages: userMessages,
+        logger: logger,
+        platform: platform,
+        fileSystem: fs,
+        flutterRoot: Cache.flutterRoot ?? '',
+      );
+
+  @override
+  Logger get logger => _logger ?? BufferLogger.test();
+
+  @override
+  TestCompilerNativeAssetsBuilder? get nativeAssetsBuilder => _nativeAssetsBuilder;
+
+  @override
+  OperatingSystemUtils get os => _os ?? FakeOperatingSystemUtils();
+
+  @override
+  OutputPreferences get outputPreferences => _outputPreferences ?? OutputPreferences.test();
+
+  @override
+  Platform get platform => _platform ?? FakePlatform();
+
+  @override
+  PreRunValidator get preRunValidator => _preRunValidator ?? const NoOpPreRunValidator();
+
+  @override
+  ProcessManager get processManager => _processManager ?? FakeProcessManager.any();
+
+  @override
+  ProcessUtils get processUtils =>
+      _processUtils ?? ProcessUtils(processManager: processManager, logger: logger);
+
+  @override
+  FlutterProjectFactory get projectFactory =>
+      _projectFactory ?? FlutterProjectFactory(fileSystem: fs, logger: logger);
+
+  @override
+  ShutdownHooks get shutdownHooks => _shutdownHooks ?? ShutdownHooks();
+
+  @override
+  Signals get signals => _signals ?? Signals.test();
+
+  @override
+  Stdio get stdio => _stdio ?? FakeStdio();

-class FakeArtifacts extends Fake implements Artifacts {}
+  @override
+  SystemClock get systemClock => _systemClock ?? const SystemClock();
+
+  @override
+  AnsiTerminal get terminal => _terminal ?? AnsiTerminal(stdio: stdio, platform: platform);
+
+  @override
+  UserMessages get userMessages => _userMessages ?? UserMessages();
+
+  @override
+  FileSystemUtils get fileSystemUtils => FileSystemUtils(fileSystem: fs, platform: platform);


In FakeToolContext, returning new instances of dependencies (like MemoryFileSystem, BufferLogger, FakeCache, etc.) on every getter invocation breaks referential transparency and state persistence. For example, accessing toolContext.fs twice will return two completely different, isolated in-memory file systems, causing state changes in one to be lost in the other.

Using late final fields instead of getters ensures that these dependencies are lazily initialized on first access and then cached for all subsequent accesses, while still allowing them to reference each other safely during initialization.

@override late final Artifacts artifacts = _artifacts ?? FakeArtifacts(fileSystem: fs); @override late final BotDetector botDetector = _botDetector ?? const FakeBotDetector(false); @override late final Cache cache = _cache ?? FakeCache(fileSystem: fs); @override late final Config config = _config ?? FakeConfig(); @override late final CustomDevicesConfig customDevicesConfig = _customDevicesConfig ?? CustomDevicesConfig.test(fileSystem: fs, logger: logger, platform: platform); @override late final FlutterVersion flutterVersion = _flutterVersion ?? FakeFlutterVersion(); @override late final FileSystem fs = _fs ?? MemoryFileSystem.test(); @override late final Git git = _git ?? Git(currentPlatform: platform, runProcessWith: processUtils); @override late final LocalEngineLocator localEngineLocator = _localEngineLocator ?? LocalEngineLocator( userMessages: userMessages, logger: logger, platform: platform, fileSystem: fs, flutterRoot: Cache.flutterRoot ?? '', ); @override late final Logger logger = _logger ?? BufferLogger.test(); @override TestCompilerNativeAssetsBuilder? get nativeAssetsBuilder => _nativeAssetsBuilder; @override late final OperatingSystemUtils os = _os ?? FakeOperatingSystemUtils(); @override late final OutputPreferences outputPreferences = _outputPreferences ?? OutputPreferences.test(); @override late final Platform platform = _platform ?? FakePlatform(); @override late final PreRunValidator preRunValidator = _preRunValidator ?? const NoOpPreRunValidator(); @override late final ProcessManager processManager = _processManager ?? FakeProcessManager.any(); @override late final ProcessUtils processUtils = _processUtils ?? ProcessUtils(processManager: processManager, logger: logger); @override late final FlutterProjectFactory projectFactory = _projectFactory ?? FlutterProjectFactory(fileSystem: fs, logger: logger); @override late final ShutdownHooks shutdownHooks = _shutdownHooks ?? ShutdownHooks(); @override late final Signals signals = _signals ?? Signals.test(); @override late final Stdio stdio = _stdio ?? FakeStdio(); @override late final SystemClock systemClock = _systemClock ?? const SystemClock(); @override late final AnsiTerminal terminal = _terminal ?? AnsiTerminal(stdio: stdio, platform: platform); @override late final UserMessages userMessages = _userMessages ?? UserMessages(); @override FileSystemUtils get fileSystemUtils => FileSystemUtils(fileSystem: fs, platform: platform);

References

Suggest simplification and refactoring: Assess whether the code can be made simpler or refactored to enhance readability and maintainability. ^(link)

Done. Addressed in commit 341b711.

gemini-code-assist · 2026-08-11T17:09:18Z

+  @override
+  CocoaPods get cocoaPods => _cocoaPods ?? FakeCocoaPods();
+
+  @override
+  CocoaPodsValidator get cocoapodsValidator => _cocoapodsValidator ?? FakeCocoaPodsValidator();
+
+  @override
+  IOSSimulatorUtils get iosSimulatorUtils => _iosSimulatorUtils ?? FakeIOSSimulatorUtils();
+
+  @override
+  IOSWorkflow get iosWorkflow => _iosWorkflow ?? FakeIOSWorkflow();
+
+  @override
+  PlistParser get plistParser => _plistParser ?? FakePlistParser();
+
+  @override
+  XCDevice get xcdevice => _xcdevice ?? FakeXCDevice();
+
+  @override
+  Xcode get xcode => _xcode ?? FakeXcode();
+
+  @override
+  XcodeProjectInterpreter get xcodeProjectInterpreter => FakeXcodeProjectInterpreter();
+}


Similar to FakeToolContext, FakeAppleContext should cache its dependencies using late final fields to ensure referential transparency and state persistence across multiple accesses in tests.

@override late final CocoaPods cocoaPods = _cocoaPods ?? FakeCocoaPods(); @override late final CocoaPodsValidator cocoapodsValidator = _cocoapodsValidator ?? FakeCocoaPodsValidator(); @override late final IOSSimulatorUtils iosSimulatorUtils = _iosSimulatorUtils ?? FakeIOSSimulatorUtils(); @override late final IOSWorkflow iosWorkflow = _iosWorkflow ?? FakeIOSWorkflow(); @override late final PlistParser plistParser = _plistParser ?? FakePlistParser(); @override late final XCDevice xcdevice = _xcdevice ?? FakeXCDevice(); @override late final Xcode xcode = _xcode ?? FakeXcode(); @override late final XcodeProjectInterpreter xcodeProjectInterpreter = FakeXcodeProjectInterpreter();

References

Suggest simplification and refactoring: Assess whether the code can be made simpler or refactored to enhance readability and maintainability. ^(link)

Done. Addressed in commit 341b711.

gemini-code-assist · 2026-08-11T17:09:19Z

+        AnsiTerminal(
+          stdio: finalStdio,
+          platform: finalPlatform,
+          now: DateTime.now(),


Using DateTime.now() directly makes the terminal's time-dependent behavior non-hermetic and unmockable in tests. Since finalSystemClock is already resolved above, we should use finalSystemClock.now() instead.

Suggested change

now: DateTime.now(),

now: finalSystemClock.now(),

Done. Addressed in commit 341b711.

gemini-code-assist · 2026-08-11T17:09:19Z

+  @override
+  GradleUtils get gradleUtils => _gradleUtils ?? FakeGradleUtils();


Similar to FakeToolContext, FakeAndroidContext should cache its gradleUtils instance using a late final field to avoid returning a new instance on every access.

Suggested change

@override

GradleUtils get gradleUtils => _gradleUtils ?? FakeGradleUtils();

@override

late final GradleUtils gradleUtils = _gradleUtils ?? FakeGradleUtils();

Done. Addressed in commit 341b711.

…ners

…s in ToolDependencies

…#12453) Manual roll Flutter from 27b098811f3b to c2437523d308 (179 revisions) Manual roll requested by [email protected] flutter/flutter@27b0988...c243752 2026-08-12 [email protected] Enable Gradle CI cache on all test targets that require android_sdk (flutter/flutter#190723) 2026-08-12 [email protected] [analysis] Reland "Added initial implementation of the flutter_analyzer_plugin (#175679)" (flutter/flutter#191022) 2026-08-12 [email protected] Switch testing to gradle bin distribution type instead of all (flutter/flutter#190738) 2026-08-12 [email protected] Convert Mockito instances in Kotlin to Mockk (flutter/flutter#189884) 2026-08-12 [email protected] Report individual test results to LUCI ResultDB (flutter/flutter#190254) 2026-08-12 [email protected] Toggleable reaction duration respects overrides (flutter/flutter#190857) 2026-08-12 [email protected] Roll Skia from e00dbd7448c4 to fee7272f5bc2 (1 revision) (flutter/flutter#191007) 2026-08-12 [email protected] Started caching text shadows by content. (flutter/flutter#190681) 2026-08-12 [email protected] Adds agent skill for spawning led tasks. (flutter/flutter#190937) 2026-08-12 [email protected] Roll Packages from aaaf246 to 94485f1 (8 revisions) (flutter/flutter#191008) 2026-08-12 [email protected] flutter_tools: validate plugin identifiers before generating registrant code (flutter/flutter#190462) 2026-08-12 [email protected] Roll Skia from 112f36148949 to e00dbd7448c4 (3 revisions) (flutter/flutter#190993) 2026-08-12 [email protected] Roll Skia from 7d366c802307 to 112f36148949 (3 revisions) (flutter/flutter#190983) 2026-08-12 [email protected] remove bringup for flavors test (flutter/flutter#190940) 2026-08-12 [email protected] Roll Skia from 1f10a20bdd61 to 7d366c802307 (2 revisions) (flutter/flutter#190980) 2026-08-12 [email protected] Remove `--no-sim-use-hardfp` flag (flutter/flutter#190790) 2026-08-12 [email protected] Roll pub packages (flutter/flutter#190977) 2026-08-12 [email protected] Roll Skia from 339bedab6766 to 1f10a20bdd61 (1 revision) (flutter/flutter#190975) 2026-08-12 [email protected] RawTooltip respects AnimationStyle updates and reverseCurve (flutter/flutter#190889) 2026-08-12 [email protected] ci: Support --target_arch option in prepare_package.dart (flutter/flutter#190960) 2026-08-12 [email protected] Roll Fuchsia Linux SDK from SFq4FVodIOQAS26Lr... to -uHuSGv3wt7QAlDwa... (flutter/flutter#190973) 2026-08-12 [email protected] Removes building of ci/android_debug_x86 as nobody should be consuming it. (flutter/flutter#190951) 2026-08-12 [email protected] Adds error about wimp_heavy not being implemented. (flutter/flutter#189945) 2026-08-11 [email protected] Add clang, cmake, and ninja deps to Linux windowing_test (flutter/flutter#190119) 2026-08-11 [email protected] [AGP 9.1.0 Migration #1] Add Android Gradle Plugin Public API migration documentation (flutter/flutter#190842) 2026-08-11 [email protected] [flutter_tools] Fix deadlock in debug adapters when process exits early (flutter/flutter#190931) 2026-08-11 [email protected] [tool] Define modular dependency injection containers and bootstrapper (flutter/flutter#190724) 2026-08-11 [email protected] [web] Unify MaskFilter and ColorFilter primitives across CanvasKit and Skwasm (flutter/flutter#190314) 2026-08-11 [email protected] Roll pub packages (flutter/flutter#190958) 2026-08-11 [email protected] [Impeller] Move image upload scheduling waits to GPU disable (flutter/flutter#190445) 2026-08-11 [email protected] Started generating the windows platform for macrobenchmarks (flutter/flutter#190932) 2026-08-11 [email protected] [web] Unify ui.Vertices (flutter/flutter#190563) 2026-08-11 [email protected] Fix accessibility_inspector service extensions map mutability (flutter/flutter#190888) 2026-08-11 [email protected] Add batch3 a11y_assessment for vpat (flutter/flutter#189042) 2026-08-11 [email protected] Remove Xcode environment when building swift tools in Xcode pre-action (flutter/flutter#190848) 2026-08-11 [email protected] [tool] Add missing play element in web test index.html to fix warning (flutter/flutter#190675) 2026-08-11 [email protected] Offload blocking work in ProcessTextPlugin to the background (flutter/flutter#189823) 2026-08-11 [email protected] [flutter_tools] Replace usages of package:dds/dap.dart with package:dap_adapters/dap_adapters.dart (flutter/flutter#190667) 2026-08-11 [email protected] Always update swift package dependencies (flutter/flutter#190886) 2026-08-11 [email protected] [flutter_tools] Add --preset option to flutter test (flutter/flutter#190878) 2026-08-11 [email protected] Include the examples cross imports checker in the analzyer. (flutter/flutter#190674) 2026-08-11 [email protected] [devicelab] Remove orphaned screenshot test files (flutter/flutter#190879) 2026-08-11 [email protected] Remove the bringup flag from the linux_arm_host_desktop_engine builder (flutter/flutter#190935) 2026-08-11 [email protected] Reduce web_skwasm_tests subshards from 8 to 2 (flutter/flutter#190728) ...

…ired non-nullable contexts (flutter#190922) ## Summary Part 2 of the modular dependency injection migration (stacked on flutter#190724). Wires explicit dependency injection into the Flutter tool entrypoints: - Wires `ToolDependencies.bootstrap` into `runner.dart` to initialize dependencies at startup. - Updates `FlutterCommandRunner` to accept non-nullable `toolContext`, `androidContext`, `appleContext`, and `toolDependencies`. - Updates `executable.dart` to forward `ToolDependencies` into `generateCommands`. - Updates `test_flutter_command_runner.dart` and hermetic test doubles. Part of flutter#47161

… discovery (flutter#191972) ## Description This PR optimizes `AndroidSdk` initialization by deferring expensive synchronous filesystem operations out of the constructor. ### Why this is needed now As part of the modular dependency injection migration ([flutter#190724](flutter#190724)), context objects like `AndroidContext` are created upfront during `ToolDependencies.bootstrap` / runner initialization rather than via the old global ambient context (`AppContext`). Previously, `AndroidSdk` was initialized lazily only when a command or service queried `globals.androidSdk` or `context.get<AndroidSdk>()`. With upfront `AndroidContext` creation, `AndroidSdk.locateAndroidSdk()` runs on tool startup for every command. Because the `AndroidSdk` constructor eagerly executed `reinitialize()`, it performed synchronous directory listings across `build-tools` and `platforms` directories and read `build.prop` files on disk. This introduced unnecessary disk I/O and latency to tool startup, including for commands completely unrelated to Android (such as `flutter config` or iOS-specific workflows). ### Changes - Defers synchronous scanning of build-tools and platform directories (`reinitialize()`) out of the `AndroidSdk` constructor so that object instantiation is fast and side-effect free. - `sdkVersions` and `latestVersion` are evaluated lazily on first access. - Retains `_fileSystem` on the instance so that explicit calls to `reinitialize()` continue to refresh platform and version state with the expected filesystem. ## Related Issues Part of [flutter#47161](flutter#47161) (flutter_tools modular dependency injection migration). ## Tests - Updated existing test in `packages/flutter_tools/test/general.shard/android/android_sdk_test.dart` (`constructing an AndroidSdk handles no matching lines in build.prop`) to access `sdk.latestVersion` so that `build.prop` parsing error-handling is executed during lazy initialization. - Added unit tests verifying: - Constructor instantiation does not initialize `sdkVersions` or `latestVersion` or scan platform directories. - `sdkVersions` and `latestVersion` evaluate lazily on first access across independent instances. - Calling `reinitialize()` updates `sdkVersions` and `latestVersion` and correctly falls back to stored `_fileSystem`.

github-actions Bot added tool Affects the "flutter" command-line tool. See also t: labels. team-android Owned by Android platform team labels Aug 7, 2026

This was referenced Aug 7, 2026

[tool] Migrate Lean Commands to explicit constructor dependency injection #190726

Closed

[tool] Migrate DoctorCommand to modular dependency injection #190758

Merged

bkonyi force-pushed the di/01-foundation branch from 36e2980 to cf41bc2 Compare August 11, 2026 14:47

github-actions Bot added team-ios Owned by iOS platform team team-macos Owned by the macOS platform team labels Aug 11, 2026

bkonyi force-pushed the di/01-foundation branch from cf41bc2 to 378a4ba Compare August 11, 2026 14:52

github-actions Bot removed team-ios Owned by iOS platform team team-macos Owned by the macOS platform team labels Aug 11, 2026

bkonyi changed the title ~~[tool] Bootstrap explicit dependency injection and wire it into the runner~~ [tool] Define modular dependency injection containers and bootstrapper Aug 11, 2026

bkonyi mentioned this pull request Aug 11, 2026

[tool] Wire dependency injection into runner and executable with required non-nullable contexts #190922

Merged

bkonyi added CICD Run CI/CD and removed team-android Owned by Android platform team labels Aug 11, 2026

[tool] Define modular dependency injection containers and bootstrapper

85aa4f1

bkonyi force-pushed the di/01-foundation branch from 378a4ba to 85aa4f1 Compare August 11, 2026 15:31

github-actions Bot added the team-android Owned by Android platform team label Aug 11, 2026

bkonyi marked this pull request as ready for review August 11, 2026 17:07

bkonyi requested a review from a team as a code owner August 11, 2026 17:07

bkonyi requested review from chingjun, gmackall and vashworth and removed request for a team August 11, 2026 17:07

gemini-code-assist Bot reviewed Aug 11, 2026

View reviewed changes

[tool] Address review comments on modular dependency injection contai…

341b711

…ners

chingjun previously approved these changes Aug 11, 2026

View reviewed changes

[tool] Make BuildTargets optional and avoid importing isolated target…

4e4beb2

…s in ToolDependencies

bkonyi dismissed chingjun’s stale review via 4e4beb2 August 11, 2026 19:47

chingjun approved these changes Aug 11, 2026

View reviewed changes

bkonyi added the autosubmit Merge PR when tree becomes green via auto submit App label Aug 11, 2026

auto-submit Bot added this pull request to the merge queue Aug 11, 2026

Merged via the queue into flutter:master with commit cad3054 Aug 12, 2026
22 checks passed

flutter-dashboard Bot removed the autosubmit Merge PR when tree becomes green via auto submit App label Aug 12, 2026

dcharkes mentioned this pull request Sep 28, 2026

[tool] Migrate TestCommand and platform runner to modular dependency injection #190789

Merged

Navigation Menu

Repository navigation

[tool] Define modular dependency injection containers and bootstrapper - #190724

[tool] Define modular dependency injection containers and bootstrapper#190724
auto-submit[bot] merged 3 commits into
flutter:masterfrom
bkonyi:di/01-foundation

bkonyi commented Aug 7, 2026 •

edited

Loading

Uh oh!

gemini-code-assist Bot left a comment

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Uh oh!

bkonyi Aug 11, 2026

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Uh oh!

bkonyi Aug 11, 2026

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Uh oh!

bkonyi Aug 11, 2026

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Uh oh!

bkonyi Aug 11, 2026

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Uh oh!

bkonyi Aug 11, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

		@override
		GradleUtils get gradleUtils => _gradleUtils ?? FakeGradleUtils();

Conversation

bkonyi commented Aug 7, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Uh oh!

gemini-code-assist Bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

bkonyi Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

bkonyi Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

bkonyi Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

bkonyi Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist Bot Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

bkonyi Aug 11, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

bkonyi commented Aug 7, 2026 •

edited

Loading