[flutter_tools] Cleanup of native asset related code (removes around 50% of the native asset related code) (#155430)

tl;dr Removes 50% (>1650 locs) of native asset related code in
`packages/flutter_tools`

Before this PR the invocation of dart build/link/dry-run was implemented
per OS. This lead to very large code duplication of almost identical,
but slightly different code. It also led to similarly duplicated test
code.

Almost the entire dart build/link/dry-run implementation is identical
across OSes. There's small variations:

- configuration of the build (e.g. android/macos/ios version, ios sdk, ...)
- determining target locations & copying the final shared libraries

This PR unifies the implementation by reducing the code to basically two
main functions:

  * `runFlutterSpecificDartBuild` which is responsible for
    - obtain flutter configuration
    - perform dart build (& link)
    - determine target location & install binaries

* `runFlutterSpecificDartDryRunOnPlatforms` which is responsible for a
similar (but not same):
    - obtain flutter configuration
    - perform dart dry run
    - determine target location

these two functions will call out to helpers for the OS specific
functionality:

* `_assetTargetLocationsForOS` for determining the location of the code
assets

* `_copyNativeCodeAssetsForOS` for copying the code assets (and possibly
overriting the install name, etc)

=> Since we get rid of the code duplication across OSes and have only a
single code path for the build/link/dry-run, we can also remove the
duplicated tests that were pretty much identical across OSes.

We also harden the building code by adding asserts, e.g.

  * the dry fun functionality should never be used by `flutter test`

  * the `build/native_assets/<os>/native_assets.yaml` should only be used
     by `flutter test` and the dry-run of `flutter run`

=> We change the tests to also comply with these invariants (so the
tests are not testing things that cannot happen in reality)

We also rename `{,Flutter}NativeAssetsBuildRunner` to disambiguate it
from the `package:native_asset_builder`'s `NativeAssetsBuildRunner`.

Author: mkustermann

packages/flutter_tools/lib/src/build_system/targets/native_assets.dart

@@ -3,22 +3,14 @@
 // found in the LICENSE file.
 
 import 'package:meta/meta.dart';
-import 'package:native_assets_builder/native_assets_builder.dart' hide NativeAssetsBuildRunner;
+import 'package:native_assets_builder/native_assets_builder.dart';
 import 'package:package_config/package_config_types.dart';
 
-import '../../android/gradle_utils.dart';
 import '../../base/common.dart';
 import '../../base/file_system.dart';
-import '../../base/platform.dart';
 import '../../build_info.dart';
 import '../../dart/package_map.dart';
-import '../../isolated/native_assets/android/native_assets.dart';
-import '../../isolated/native_assets/ios/native_assets.dart';
-import '../../isolated/native_assets/linux/native_assets.dart';
-import '../../isolated/native_assets/macos/native_assets.dart';
 import '../../isolated/native_assets/native_assets.dart';
-import '../../isolated/native_assets/windows/native_assets.dart';
-import '../../macos/xcode.dart';
 import '../build_system.dart';
 import '../depfile.dart';
 import '../exceptions.dart';
@@ -43,20 +35,21 @@ import 'common.dart';
 /// rebuild.
 class NativeAssets extends Target {
   const NativeAssets({
-    @visibleForTesting NativeAssetsBuildRunner? buildRunner,
+    @visibleForTesting FlutterNativeAssetsBuildRunner? buildRunner,
   }) : _buildRunner = buildRunner;
 
-  final NativeAssetsBuildRunner? _buildRunner;
+  final FlutterNativeAssetsBuildRunner? _buildRunner;
 
   @override
   Future<void> build(Environment environment) async {
     final String? nativeAssetsEnvironment = environment.defines[kNativeAssets];
-    final List<Uri> dependencies;
     final FileSystem fileSystem = environment.fileSystem;
-    final File nativeAssetsFile = environment.buildDir.childFile('native_assets.yaml');
+    final Uri nativeAssetsFileUri = environment.buildDir.childFile('native_assets.yaml').uri;
+
+    final DartBuildResult result;
     if (nativeAssetsEnvironment == 'false') {
-      dependencies = <Uri>[];
-      await writeNativeAssetsYaml(KernelAssets(), environment.buildDir.uri, fileSystem);
+      result = const DartBuildResult.empty();
+      await writeNativeAssetsYaml(KernelAssets(), nativeAssetsFileUri, fileSystem);
     } else {
       final String? targetPlatformEnvironment = environment.defines[kTargetPlatform];
       if (targetPlatformEnvironment == null) {
@@ -69,300 +62,46 @@ class NativeAssets extends Target {
         fileSystem.file(environment.packageConfigPath),
         logger: environment.logger,
       );
-      final NativeAssetsBuildRunner buildRunner = _buildRunner ??
-          NativeAssetsBuildRunnerImpl(
+      final FlutterNativeAssetsBuildRunner buildRunner = _buildRunner ??
+          FlutterNativeAssetsBuildRunnerImpl(
             projectUri,
             environment.packageConfigPath,
             packageConfig,
             fileSystem,
             environment.logger,
           );
 
-      switch (targetPlatform) {
-        case TargetPlatform.ios:
-          dependencies = await _buildIOS(
-            environment,
-            projectUri,
-            fileSystem,
-            buildRunner,
-          );
-        case TargetPlatform.darwin:
-          dependencies = await _buildMacOS(
-            environment,
-            projectUri,
-            fileSystem,
-            buildRunner,
-          );
-        case TargetPlatform.linux_arm64:
-        case TargetPlatform.linux_x64:
-          dependencies = await _buildLinux(
-            environment,
-            targetPlatform,
-            projectUri,
-            fileSystem,
-            buildRunner,
-          );
-        case TargetPlatform.windows_arm64:
-        case TargetPlatform.windows_x64:
-          dependencies = await _buildWindows(
-            environment,
-            targetPlatform,
-            projectUri,
-            fileSystem,
-            buildRunner,
-          );
-        case TargetPlatform.tester:
-          if (const LocalPlatform().isMacOS) {
-            (_, dependencies) = await buildNativeAssetsMacOS(
-              buildMode: BuildMode.debug,
-              projectUri: projectUri,
-              codesignIdentity: environment.defines[kCodesignIdentity],
-              yamlParentDirectory: environment.buildDir.uri,
-              fileSystem: fileSystem,
-              buildRunner: buildRunner,
-              flutterTester: true,
-            );
-          } else if (const LocalPlatform().isLinux) {
-            (_, dependencies) = await buildNativeAssetsLinux(
-              buildMode: BuildMode.debug,
-              projectUri: projectUri,
-              yamlParentDirectory: environment.buildDir.uri,
-              fileSystem: fileSystem,
-              buildRunner: buildRunner,
-              flutterTester: true,
-            );
-          } else if (const LocalPlatform().isWindows) {
-            (_, dependencies) = await buildNativeAssetsWindows(
-              buildMode: BuildMode.debug,
-              projectUri: projectUri,
-              yamlParentDirectory: environment.buildDir.uri,
-              fileSystem: fileSystem,
-              buildRunner: buildRunner,
-              flutterTester: true,
-            );
-          } else {
-            // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
-            // Write the file we claim to have in the [outputs].
-            await writeNativeAssetsYaml(KernelAssets(), environment.buildDir.uri, fileSystem);
-            dependencies = <Uri>[];
-          }
-        case TargetPlatform.android_arm:
-        case TargetPlatform.android_arm64:
-        case TargetPlatform.android_x64:
-        case TargetPlatform.android_x86:
-        case TargetPlatform.android:
-          (_, dependencies) = await _buildAndroid(
-            environment,
-            targetPlatform,
-            projectUri,
-            fileSystem,
-            buildRunner,
-          );
-        case TargetPlatform.fuchsia_arm64:
-        case TargetPlatform.fuchsia_x64:
-        case TargetPlatform.web_javascript:
-          // TODO(dacoharkes): Implement other OSes. https://github.com/flutter/flutter/issues/129757
-          // Write the file we claim to have in the [outputs].
-          await writeNativeAssetsYaml(KernelAssets(), environment.buildDir.uri, fileSystem);
-          dependencies = <Uri>[];
-      }
+      (result, _) = await runFlutterSpecificDartBuild(
+        environmentDefines: environment.defines,
+        buildRunner: buildRunner,
+        targetPlatform: targetPlatform,
+        projectUri: projectUri,
+        nativeAssetsYamlUri : nativeAssetsFileUri,
+        fileSystem: fileSystem,
+      );
     }
 
     final Depfile depfile = Depfile(
       <File>[
-        for (final Uri dependency in dependencies) fileSystem.file(dependency),
+        for (final Uri dependency in result.dependencies) fileSystem.file(dependency),
       ],
       <File>[
-        nativeAssetsFile,
+        fileSystem.file(nativeAssetsFileUri),
       ],
     );
     final File outputDepfile = environment.buildDir.childFile('native_assets.d');
     if (!outputDepfile.parent.existsSync()) {
       outputDepfile.parent.createSync(recursive: true);
     }
     environment.depFileService.writeToFile(depfile, outputDepfile);
-    if (!await nativeAssetsFile.exists()) {
-      throwToolExit("${nativeAssetsFile.path} doesn't exist.");
+    if (!await fileSystem.file(nativeAssetsFileUri).exists()) {
+      throwToolExit("${nativeAssetsFileUri.path} doesn't exist.");
     }
     if (!await outputDepfile.exists()) {
       throwToolExit("${outputDepfile.path} doesn't exist.");
     }
   }
 
-  Future<List<Uri>> _buildWindows(
-    Environment environment,
-    TargetPlatform targetPlatform,
-    Uri projectUri,
-    FileSystem fileSystem,
-    NativeAssetsBuildRunner buildRunner,
-  ) async {
-    final String? environmentBuildMode = environment.defines[kBuildMode];
-    if (environmentBuildMode == null) {
-      throw MissingDefineException(kBuildMode, name);
-    }
-    final BuildMode buildMode = BuildMode.fromCliName(environmentBuildMode);
-    final (_, List<Uri> dependencies) = await buildNativeAssetsWindows(
-      targetPlatform: targetPlatform,
-      buildMode: buildMode,
-      projectUri: projectUri,
-      yamlParentDirectory: environment.buildDir.uri,
-      fileSystem: fileSystem,
-      buildRunner: buildRunner,
-    );
-    return dependencies;
-  }
-
-  Future<List<Uri>> _buildLinux(
-    Environment environment,
-    TargetPlatform targetPlatform,
-    Uri projectUri,
-    FileSystem fileSystem,
-    NativeAssetsBuildRunner buildRunner,
-  ) async {
-    final String? environmentBuildMode = environment.defines[kBuildMode];
-    if (environmentBuildMode == null) {
-      throw MissingDefineException(kBuildMode, name);
-    }
-    final BuildMode buildMode = BuildMode.fromCliName(environmentBuildMode);
-    final (_, List<Uri> dependencies) = await buildNativeAssetsLinux(
-      targetPlatform: targetPlatform,
-      buildMode: buildMode,
-      projectUri: projectUri,
-      yamlParentDirectory: environment.buildDir.uri,
-      fileSystem: fileSystem,
-      buildRunner: buildRunner,
-    );
-    return dependencies;
-  }
-
-  Future<List<Uri>> _buildMacOS(
-    Environment environment,
-    Uri projectUri,
-    FileSystem fileSystem,
-    NativeAssetsBuildRunner buildRunner,
-  ) async {
-    final List<DarwinArch> darwinArchs =
-        _emptyToNull(environment.defines[kDarwinArchs])
-                ?.split(' ')
-                .map(getDarwinArchForName)
-                .toList() ??
-            <DarwinArch>[DarwinArch.x86_64, DarwinArch.arm64];
-    final String? environmentBuildMode = environment.defines[kBuildMode];
-    if (environmentBuildMode == null) {
-      throw MissingDefineException(kBuildMode, name);
-    }
-    final BuildMode buildMode = BuildMode.fromCliName(environmentBuildMode);
-    final (_, List<Uri> dependencies) = await buildNativeAssetsMacOS(
-      darwinArchs: darwinArchs,
-      buildMode: buildMode,
-      projectUri: projectUri,
-      codesignIdentity: environment.defines[kCodesignIdentity],
-      yamlParentDirectory: environment.buildDir.uri,
-      fileSystem: fileSystem,
-      buildRunner: buildRunner,
-    );
-    return dependencies;
-  }
-
-  Future<List<Uri>> _buildIOS(
-    Environment environment,
-    Uri projectUri,
-    FileSystem fileSystem,
-    NativeAssetsBuildRunner buildRunner,
-  ) {
-    final List<DarwinArch> iosArchs =
-        _emptyToNull(environment.defines[kIosArchs])
-                ?.split(' ')
-                .map(getIOSArchForName)
-                .toList() ??
-            <DarwinArch>[DarwinArch.arm64];
-    final String? environmentBuildMode = environment.defines[kBuildMode];
-    if (environmentBuildMode == null) {
-      throw MissingDefineException(kBuildMode, name);
-    }
-    final BuildMode buildMode = BuildMode.fromCliName(environmentBuildMode);
-    final String? sdkRoot = environment.defines[kSdkRoot];
-    if (sdkRoot == null) {
-      throw MissingDefineException(kSdkRoot, name);
-    }
-    final EnvironmentType environmentType =
-        environmentTypeFromSdkroot(sdkRoot, environment.fileSystem)!;
-    return buildNativeAssetsIOS(
-      environmentType: environmentType,
-      darwinArchs: iosArchs,
-      buildMode: buildMode,
-      projectUri: projectUri,
-      codesignIdentity: environment.defines[kCodesignIdentity],
-      fileSystem: fileSystem,
-      buildRunner: buildRunner,
-      yamlParentDirectory: environment.buildDir.uri,
-    );
-  }
-
-  Future<(Uri? nativeAssetsYaml, List<Uri> dependencies)> _buildAndroid(
-      Environment environment,
-      TargetPlatform targetPlatform,
-      Uri projectUri,
-      FileSystem fileSystem,
-      NativeAssetsBuildRunner buildRunner) {
-    final String? androidArchsEnvironment = environment.defines[kAndroidArchs];
-    final List<AndroidArch> androidArchs = _androidArchs(
-      targetPlatform,
-      androidArchsEnvironment,
-    );
-    final int targetAndroidNdkApi =
-        int.parse(environment.defines[kMinSdkVersion] ?? minSdkVersion);
-    final String? environmentBuildMode = environment.defines[kBuildMode];
-    if (environmentBuildMode == null) {
-      throw MissingDefineException(kBuildMode, name);
-    }
-    final BuildMode buildMode = BuildMode.fromCliName(environmentBuildMode);
-    return buildNativeAssetsAndroid(
-      buildMode: buildMode,
-      projectUri: projectUri,
-      yamlParentDirectory: environment.buildDir.uri,
-      fileSystem: fileSystem,
-      buildRunner: buildRunner,
-      androidArchs: androidArchs,
-      targetAndroidNdkApi: targetAndroidNdkApi,
-    );
-  }
-
-  List<AndroidArch> _androidArchs(
-    TargetPlatform targetPlatform,
-    String? androidArchsEnvironment,
-  ) {
-    switch (targetPlatform) {
-      case TargetPlatform.android_arm:
-        return <AndroidArch>[AndroidArch.armeabi_v7a];
-      case TargetPlatform.android_arm64:
-        return <AndroidArch>[AndroidArch.arm64_v8a];
-      case TargetPlatform.android_x64:
-        return <AndroidArch>[AndroidArch.x86_64];
-      case TargetPlatform.android_x86:
-        return <AndroidArch>[AndroidArch.x86];
-      case TargetPlatform.android:
-        if (androidArchsEnvironment == null) {
-          throw MissingDefineException(kAndroidArchs, name);
-        }
-        return androidArchsEnvironment
-            .split(' ')
-            .map(getAndroidArchForName)
-            .toList();
-      case TargetPlatform.darwin:
-      case TargetPlatform.fuchsia_arm64:
-      case TargetPlatform.fuchsia_x64:
-      case TargetPlatform.ios:
-      case TargetPlatform.linux_arm64:
-      case TargetPlatform.linux_x64:
-      case TargetPlatform.tester:
-      case TargetPlatform.web_javascript:
-      case TargetPlatform.windows_x64:
-      case TargetPlatform.windows_arm64:
-        throwToolExit('Unsupported Android target platform: $targetPlatform.');
-    }
-  }
-
   @override
   List<String> get depfiles => <String>[
     'native_assets.d',
@@ -390,10 +129,3 @@ class NativeAssets extends Target {
     Source.pattern('{BUILD_DIR}/native_assets.yaml'),
   ];
 }
-
-String? _emptyToNull(String? input) {
-  if (input == null || input.isEmpty) {
-    return null;
-  }
-  return input;
-}