[flutter_tools] add support for FLUTTER_LOCAL_ENGINE config in test d…

…river
flutter · fluttergithubbot · Sep 15, 2020 · Sep 14, 2020 · Sep 14, 2020 · Sep 14, 2020
commit 6cce488d80b1d4097cdc281cf60589c015d0b944
diff --git a/packages/flutter_tools/README.md b/packages/flutter_tools/README.md
@@ -22,7 +22,7 @@ $ ../../bin/flutter --version
 
 To run Flutter Tools from source, in this directory run:
 ```shell
-$ ../../bin/cache/dart-sdk/bin/dart bin/flutter_tools.dart
+$ ../../bin/dart bin/flutter_tools.dart
 ```
 followed by command-line arguments, as usual.
 
@@ -56,24 +56,38 @@ that add new code should aim to increase coverage. In particular, the coverage
 of the diff should be close to the average coverage, and should ideally be
 better.
 
+#### Using local engine builds in integration tests
+
+The integration tests can be configured to use a specific local engine
+variant by setting the `FLUTTER_LOCAL_ENGINE` environment variable to the
+name of the local engine (e.g. "android_debug_unopt"). If the local engine build
+requires a source path, this can be provided by setting the `FLUTTER_LOCAL_ENGINE_SRC_PATH`
+environment variable. This second variable is not necessary if the `flutter` and
+`engine` checkouts are in adjacent directories.
+
+```shell
+export FLUTTER_LOCAL_ENGINE=android_debug_unopt
+../../bin/dart test test/integration.shard/some_test_case
+```
+
 ### Running the tests
 
 To run the tests in the `test/` directory, first ensure that there are no
 connected devices. Then, in this directory run:
 ```shell
-$ ../../bin/cache/dart-sdk/bin/pub run test
+$ ../../bin/dart pub run test
 ```
 
 The tests in `test/integration.shard` are slower to run than the tests in
 `test/general.shard`. To run only the tests in `test/general.shard`, in this
 directory run:
 ```shell
-$ ../../bin/cache/dart-sdk/bin/pub run test test/general.shard
+$ ../../bin/dart pub run test test/general.shard
 ```
 
 To run the tests in a specific file, run:
 ```shell
-$ ../../bin/cache/dart-sdk/bin/pub run test test/general.shard/utils_test.dart
+$ ../../bin/dart pub run test test/general.shard/utils_test.dart
 ```
 
 ### Forcing snapshot regeneration

diff --git a/packages/flutter_tools/test/integration.shard/test_driver.dart b/packages/flutter_tools/test/integration.shard/test_driver.dart
@@ -31,6 +31,9 @@ import 'test_utils.dart';
 // taking a long time are printed to the console.
 const bool _printDebugOutputToStdOut = false;
 
+const String kLocalEngineEnvironment = 'FLUTTER_LOCAL_ENGINE';
+const String kLocalEngineLocation = 'FLUTTER_LOCAL_ENGINE_SRC_PATH';
+
 final DateTime startTime = DateTime.now();
 
 const Duration defaultTimeout = Duration(seconds: 5);
@@ -452,6 +455,10 @@ class FlutterRunTestDriver extends FlutterTestDriver {
           '--disable-service-auth-codes',
         if (machine) '--machine',
         if (!spawnDdsInstance) '--disable-dds',
+        if (platform.environment.containsKey(kLocalEngineEnvironment))
+          '--local-engine=${platform.environment[kLocalEngineEnvironment]}',
+        if (platform.environment.containsKey(kLocalEngineLocation))
+          '--local-engine-src-path=${platform.environment[kLocalEngineLocation]}',
         '-d',
         if (chrome)
           ...<String>[
@@ -482,6 +489,10 @@ class FlutterRunTestDriver extends FlutterTestDriver {
     await _setupProcess(
       <String>[
         'attach',
+        if (platform.environment.containsKey(kLocalEngineEnvironment))
+          '--local-engine=${platform.environment[kLocalEngineEnvironment]}',
+        if (platform.environment.containsKey(kLocalEngineLocation))
+          '--local-engine-src-path=${platform.environment[kLocalEngineLocation]}',
         '--machine',
         if (!spawnDdsInstance)
           '--disable-dds',
@@ -705,6 +716,10 @@ class FlutterTestTestDriver extends FlutterTestDriver {
   }) async {
     await _setupProcess(<String>[
       'test',
+      if (platform.environment.containsKey(kLocalEngineEnvironment))
+        '--local-engine=${platform.environment[kLocalEngineEnvironment]}',
+      if (platform.environment.containsKey(kLocalEngineLocation))
+        '--local-engine-src-path=${platform.environment[kLocalEngineLocation]}',
       '--disable-service-auth-codes',
       '--machine',
       if (coverage)