flutter · auto-submit · Apr 28, 2026 · Apr 16, 2026 · Apr 16, 2026 · Apr 16, 2026
diff --git a/docs/contributing/testing/Test-Types-Overview.md b/docs/contributing/testing/Test-Types-Overview.md
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+# Flutter Codebase Test Inventory
+
+This file lists and categorizes the test files found in the Flutter codebase.
+Due to the large number of tests (over 6000 files), they are grouped by category and location.
+
+## Runtime Length
+- **Sub-second**: < 1 second (Simple unit tests, e.g., in `dev/tools`)
+- **Fast**: < 10 seconds (Most unit tests, simple widget tests)
+- **Medium**: 10-60 seconds (Complex widget tests, some tool tests)
+- **Slow**: > 60 seconds (Integration tests, devicelab tasks, analyze script)
+
+## Groupings
+
+### 1. Framework Tests
+- **Location**: `packages/flutter/test/`
+- **Language**: Dart
+- **Description**: Unit and Widget tests for the Flutter framework.
+- **Documentation**:
+  - [Running-and-writing-tests.md](Running-and-writing-tests.md)
+  - [Writing-a-golden-file-test-for-package-flutter.md](Writing-a-golden-file-test-for-package-flutter.md)
+  - [Leak-tracking.md](Leak-tracking.md)
+- **Run Locally**: Yes.
+- **Commands**:
+  - Run all tests in a directory: `bin/flutter test packages/flutter/test/foundation`
+  - Run a specific test: `bin/flutter test packages/flutter/test/foundation/assertions_test.dart`
+- **Speed**: Fast (< 10 seconds) for individual tests when environment is working.
+- **Count**: ~1000+ files.
+
+### 2. Tool Tests
+- **Location**: `packages/flutter_tools/test/`
+- **Language**: Dart
+- **Description**: Where the flutter tool tests live.
+- **Documentation**: [README.md](../../../packages/flutter_tools/README.md)
+- **Run Locally**: Yes.
+- **Commands**:
+  - Run general unit tests: `bin/flutter test packages/flutter_tools/test/general.shard`
+  - Run a specific test: `bin/flutter test packages/flutter_tools/test/general.shard/base_utils_test.dart`
+  - Run integration tests: `bin/flutter test packages/flutter_tools/test/integration.shard` (Requires `FLUTTER_ROOT` environment variable).
+- **Speed**: Fast (< 10 seconds) for general shard tests, Medium to Slow for integration tests.
+- **Count**: ~500+ files.
+
+### 3. DeviceLab Tests
+- **Location**: `dev/devicelab/`
+- **Language**: Dart
+- **Description**: Performance and integration tests run in the Flutter DeviceLab.
+- **Documentation**:
+  - [README.md](../../../dev/devicelab/README.md)
+  - [How-to-write-a-memory-test-for-Flutter.md](How-to-write-a-memory-test-for-Flutter.md)
+  - [How-to-write-a-render-speed-test-for-Flutter.md](How-to-write-a-render-speed-test-for-Flutter.md)
+- **Run Locally**: Partially. May require a physical device or emulator and specific environment setup (e.g., `ANDROID_SDK_ROOT`).
+- **Commands**:
+  - Run a task: `../../bin/cache/dart-sdk/bin/dart bin/test_runner.dart test -t {NAME_OF_TEST}` (Run from `dev/devicelab`).
+  - Example: `../../bin/cache/dart-sdk/bin/dart bin/test_runner.dart test -t complex_layout__start_up`
+- **Speed**: Slow (> 60 seconds).
+- **Count**: ~100+ files.
+
+### 4. Benchmarks
+- **Location**: `dev/benchmarks/`
+- **Language**: Dart
+- **Description**: Performance benchmarks.
+- **Documentation**:
+  - [README.md](../../../dev/devicelab/README.md) (Benchmarks are run as DeviceLab tasks).
+  - [How-to-write-a-memory-test-for-Flutter.md](How-to-write-a-memory-test-for-Flutter.md)
+  - [How-to-write-a-render-speed-test-for-Flutter.md](How-to-write-a-render-speed-test-for-Flutter.md)
+- **Run Locally**: Partially, same requirements as DeviceLab tests.
+- **Commands**: See DeviceLab Tests.
+- **Speed**: Slow (> 60 seconds).
+- **Count**: ~160+ files.
+
+### 5. Analysis and Lint Tests
+- **Key Files**:
+  - `dev/bots/analyze.dart`: Enforces style and structure rules.
+  - `dev/bots/test.dart`: Main test orchestrator.
+- **Documentation**: [Running-and-writing-tests.md](Running-and-writing-tests.md)
+- **Run Locally**: Yes.
+- **Commands**:
+  - Run analysis: `bin/cache/dart-sdk/bin/dart --enable-asserts dev/bots/analyze.dart` (Verified locally, takes > 60 seconds for full run).
+- **Speed**: Slow (> 60 seconds) for full execution.
+
+### 6. Package Tests
+- **Location**: `packages/*/test/` (excluding `flutter` and `flutter_tools`)
+- **Language**: Dart
+- **Description**: Tests for packages. Any folder with a `pubspec.yaml` file is considered a package and may contain a `test/` directory.
+- **Documentation**: [Running-and-writing-tests.md](Running-and-writing-tests.md)
+- **Run Locally**: Yes.
+- **Commands**:
+  - Run tests in a package: `bin/flutter test packages/<package_name>/test`
+- **Speed**: Fast (< 10 seconds) for individual tests.
+
+### 7. Engine Tests
+- **Location**: `engine/src` (in the [flutter/engine](https://github.com/flutter/engine) repository)
+- **Language**: C++, Dart, Java, Kotlin, etc.
+- **Description**: Tests for the Flutter engine.
+- **Documentation**: [Testing-the-engine.md](../../engine/testing/Testing-the-engine.md)
+- **Run Locally**: Yes, but requires the complete Engine development environment (GN, Ninja, etc.).
+- **Commands**:
+  - **Using `run_tests.py` from `engine/src/flutter`**:
+    - Run C++ tests: `testing/run_tests.py --type=engine`
+    - Run Java tests: `testing/run_tests.py --type=java`
+    - Run Dart tests: `testing/run_tests.py --type=dart`
+  - **Using `et` (Engine Tool)**:
+    - Run a test target: `et test //flutter/impeller:impeller_unittests`
+    - Query test targets: `et query targets --testonly`
+- **Speed**: Fast for individual unit tests, Slow for full suites.