[native_assets_cli] Add HookInput.outputFile (#1882)

Pass in a path to where the `output.json` should be written.

This enables the output file to not be written into the output directory but next to it. This is cleaner.

I don't remember where we discussed this, but some references to adding the output json can be found in the discussions here:

* #1738

pkgs/native_assets_builder/lib/src/build_runner/build_runner.dart

@@ -146,6 +146,7 @@ class NativeAssetsBuildRunner {
       inputBuilder.setupShared(
         packageName: package.name,
         packageRoot: packageLayout.packageRoot(package.name),
+        outputFile: buildDirUri.resolve('output.json'),
         outputDirectory: outDirUri,
         outputDirectoryShared: outDirSharedUri,
       );
@@ -244,6 +245,7 @@ class NativeAssetsBuildRunner {
       inputBuilder.setupShared(
         packageName: package.name,
         packageRoot: packageLayout.packageRoot(package.name),
+        outputFile: buildDirUri.resolve('output.json'),
         outputDirectory: outDirUri,
         outputDirectoryShared: outDirSharedUri,
       );
@@ -350,21 +352,27 @@ class NativeAssetsBuildRunner {
         }
         final (hookKernelFile, hookHashes) = hookCompileResult;
 
-        final buildOutputFile =
-            _fileSystem.file(input.outputDirectory.resolve(hook.outputName));
+        final buildOutputFile = _fileSystem.file(input.outputFile);
+        final buildOutputFileDeprecated = _fileSystem
+            // ignore: deprecated_member_use
+            .file(input.outputDirectory.resolve(hook.outputNameDeprecated));
+
         final dependenciesHashFile = input.outputDirectory
             .resolve('../dependencies.dependencies_hash_file.json');
         final dependenciesHashes =
             DependenciesHashFile(_fileSystem, fileUri: dependenciesHashFile);
         final lastModifiedCutoffTime = DateTime.now();
-        if (buildOutputFile.existsSync() && await dependenciesHashes.exists()) {
+        if ((buildOutputFile.existsSync() ||
+                buildOutputFileDeprecated.existsSync()) &&
+            await dependenciesHashes.exists()) {
           late final HookOutput output;
           try {
-            output = _readHookOutputFromUri(hook, buildOutputFile);
+            output = _readHookOutputFromUri(
+                hook, buildOutputFile, buildOutputFileDeprecated);
           } on FormatException catch (e) {
             logger.severe('''
 Building assets for package:${input.packageName} failed.
-${hook.outputName} contained a format error.
+${input.outputFile.toFilePath()} contained a format error.
 
 Contents: ${buildOutputFile.readAsStringSync()}.
 ${e.message}
@@ -458,12 +466,20 @@ ${e.message}
         const JsonEncoder.withIndent(' ').convert(input.json);
     logger.info('input.json contents: $inputFileContents');
     await _fileSystem.file(inputFile).writeAsString(inputFileContents);
-    final hookOutputUri = input.outputDirectory.resolve(hook.outputName);
+    final hookOutputUri = input.outputFile;
     final hookOutputFile = _fileSystem.file(hookOutputUri);
     if (await hookOutputFile.exists()) {
       // Ensure we'll never read outdated build results.
       await hookOutputFile.delete();
     }
+    final hookOutputUriDeprecated =
+        // ignore: deprecated_member_use
+        input.outputDirectory.resolve(hook.outputNameDeprecated);
+    final hookOutputFileDeprecated = _fileSystem.file(hookOutputUriDeprecated);
+    if (await hookOutputFileDeprecated.exists()) {
+      // Ensure we'll never read outdated build results.
+      await hookOutputFileDeprecated.delete();
+    }
 
     final arguments = [
       '--packages=${packageConfigUri.toFilePath()}',
@@ -508,7 +524,11 @@ ${e.message}
         return null;
       }
 
-      final output = _readHookOutputFromUri(hook, hookOutputFile);
+      final output = _readHookOutputFromUri(
+        hook,
+        hookOutputFile,
+        hookOutputFileDeprecated,
+      );
       final errors = await _validate(input, output, packageLayout, validator);
       if (errors.isNotEmpty) {
         _printErrors(
@@ -521,7 +541,7 @@ ${e.message}
     } on FormatException catch (e) {
       logger.severe('''
 Building assets for package:${input.packageName} failed.
-${hook.outputName} contained a format error.
+${input.outputFile.toFilePath()} contained a format error.
 
 Contents: ${hookOutputFile.readAsStringSync()}.
 ${e.message}
@@ -780,10 +800,17 @@ ${compileResult.stdout}
     return (buildPlan, packageGraph);
   }
 
-  HookOutput _readHookOutputFromUri(Hook hook, File hookOutputFile) {
+  HookOutput _readHookOutputFromUri(
+    Hook hook,
+    File hookOutputFile,
+    // TODO(dcharkes): Remove when hooks with 1.7.0 are no longer supported.
+    File hookOutputFileDeprecated,
+  ) {
     final decode = const Utf8Decoder().fuse(const JsonDecoder()).convert;
+    final file =
+        hookOutputFile.existsSync() ? hookOutputFile : hookOutputFileDeprecated;
     final hookOutputJson =
-        decode(hookOutputFile.readAsBytesSync()) as Map<String, Object?>;
+        decode(file.readAsBytesSync()) as Map<String, Object?>;
     return hook == Hook.build
         ? BuildOutput(hookOutputJson)
         : LinkOutput(hookOutputJson);

pkgs/native_assets_builder/test/build_runner/build_runner_build_output_format_test.dart

@@ -49,7 +49,7 @@ void main() async {
           } else {
             expect(
               fullLog,
-              contains('build_output.json contained a format error.'),
+              contains('output.json contained a format error.'),
             );
           }
         }

pkgs/native_assets_builder/test/test_data/native_dynamic_linking_test.dart

@@ -21,6 +21,7 @@ void main() async {
   test(
     'native_dynamic_linking build',
     () => inTempDir((tempUri) async {
+      final buildOutputUri = tempUri.resolve('build_output.json');
       final outputDirectory = tempUri.resolve('out/');
       await Directory.fromUri(outputDirectory).create();
       final outputDirectoryShared = tempUri.resolve('out_shared/');
@@ -35,6 +36,7 @@ void main() async {
         ..setupShared(
           packageName: name,
           packageRoot: testPackageUri,
+          outputFile: buildOutputUri,
           outputDirectory: outputDirectory,
           outputDirectoryShared: outputDirectoryShared,
         )
@@ -69,7 +71,6 @@ void main() async {
       }
       expect(processResult.exitCode, 0);
 
-      final buildOutputUri = outputDirectory.resolve('build_output.json');
       final buildOutput = BuildOutput(
           json.decode(await File.fromUri(buildOutputUri).readAsString())
               as Map<String, Object?>);

pkgs/native_assets_builder/test/test_data/transformer_test.dart

@@ -33,6 +33,7 @@ void main() async {
         logger: logger,
       );
 
+      final buildOutputUri = tempUri.resolve('build_output.json');
       final outputDirectory = tempUri.resolve('out/');
       await Directory.fromUri(outputDirectory).create();
       final outputDirectoryShared = tempUri.resolve('out_shared/');
@@ -50,6 +51,7 @@ void main() async {
           ..setupShared(
             packageName: packageName,
             packageRoot: packageUri,
+            outputFile: buildOutputUri,
             outputDirectory: outputDirectory,
             outputDirectoryShared: outputDirectoryShared,
           )
@@ -87,7 +89,6 @@ void main() async {
         expect(processResult.exitCode, 0);
         stdout = processResult.stdout as String;
 
-        final buildOutputUri = outputDirectory.resolve('build_output.json');
         output = BuildOutput(
             json.decode(await File.fromUri(buildOutputUri).readAsString())
                 as Map<String, Object?>);

pkgs/native_assets_builder/test_data/wrong_build_output/hook/build.dart

@@ -12,8 +12,7 @@ void main(List<String> args) async {
   final inputPath = getInputArgument(args);
   final buildInput = BuildInput(
       json.decode(File(inputPath).readAsStringSync()) as Map<String, Object?>);
-  await File.fromUri(buildInput.outputDirectory.resolve('build_output.json'))
-      .writeAsString(_wrongContents);
+  await File.fromUri(buildInput.outputFile).writeAsString(_wrongContents);
 }
 
 const _wrongContents = '''

pkgs/native_assets_builder/test_data/wrong_build_output_2/hook/build.dart

@@ -12,8 +12,7 @@ void main(List<String> args) async {
   final inputPath = getInputArgument(args);
   final buildInput = BuildInput(
       json.decode(File(inputPath).readAsStringSync()) as Map<String, Object?>);
-  await File.fromUri(buildInput.outputDirectory.resolve('build_output.json'))
-      .writeAsString(_wrongContents);
+  await File.fromUri(buildInput.outputFile).writeAsString(_wrongContents);
 }
 
 const _wrongContents = '''

pkgs/native_assets_builder/test_data/wrong_build_output_3/hook/build.dart

@@ -12,8 +12,7 @@ void main(List<String> args) async {
   final inputPath = getInputArgument(args);
   final buildInput = BuildInput(
       json.decode(File(inputPath).readAsStringSync()) as Map<String, Object?>);
-  await File.fromUri(buildInput.outputDirectory.resolve('build_output.json'))
-      .writeAsString(_rightContents);
+  await File.fromUri(buildInput.outputFile).writeAsString(_rightContents);
   exit(1);
 }
 
@@ -22,5 +21,5 @@ const _rightContents = '''{
   "encodedAssets": [],
   "dependencies": [],
   "metadata": {},
-  "version": "1.7.0"
+  "version": "1.8.0"
 }''';

pkgs/native_assets_cli/CHANGELOG.md

@@ -6,6 +6,7 @@
   shouldn't change on subsequent invocations of the same flutter or dart command
   for the same target. The `outputDirectory` is the same if the config is the
   same.
+- **Breaking change** The `output.json` is now part of `BuildInput`.
 
 ## 0.10.0
 

pkgs/native_assets_cli/example/build/download_asset/tool/build.dart

@@ -70,12 +70,15 @@ BuildInput createBuildInput(
       packageRoot.resolve('.dart_tool/download_asset/$targetName/');
   final outputDirectoryShared =
       packageRoot.resolve('.dart_tool/download_asset/shared/');
+  final outputFile =
+      packageRoot.resolve('.dart_tool/download_asset/output.json');
 
   final os = OS.fromString(osString);
   final inputBuilder = BuildInputBuilder()
     ..setupShared(
         packageRoot: packageRoot,
         packageName: 'download_asset',
+        outputFile: outputFile,
         outputDirectory: outputDirectory,
         outputDirectoryShared: outputDirectoryShared)
     ..config.setupShared(

pkgs/native_assets_cli/lib/src/api/build.dart

@@ -110,8 +110,7 @@ Future<void> build(
   if (errors.isEmpty) {
     final jsonOutput =
         const JsonEncoder().fuse(const Utf8Encoder()).convert(output.json);
-    await File.fromUri(input.outputDirectory.resolve('build_output.json'))
-        .writeAsBytes(jsonOutput);
+    await File.fromUri(input.outputFile).writeAsBytes(jsonOutput);
   } else {
     final message = [
       'The output contained unsupported output:',

pkgs/native_assets_cli/lib/src/api/link.dart

@@ -51,8 +51,7 @@ Future<void> link(
   if (errors.isEmpty) {
     final jsonOutput =
         const JsonEncoder().fuse(const Utf8Encoder()).convert(output.json);
-    await File.fromUri(input.outputDirectory.resolve('link_output.json'))
-        .writeAsBytes(jsonOutput);
+    await File.fromUri(input.outputFile).writeAsBytes(jsonOutput);
   } else {
     final message = [
       'The output contained unsupported output:',

pkgs/native_assets_cli/lib/src/config.dart

@@ -52,6 +52,9 @@ sealed class HookInput {
   /// each other.
   final Uri outputDirectoryShared;
 
+  /// The file to write the [HookOutput] to at the end of a hook invocation.
+  Uri get outputFile;
+
   /// The name of the package the assets are built for.
   final String packageName;
 
@@ -91,9 +94,11 @@ sealed class HookInputBuilder {
     required String packageName,
     required Uri outputDirectory,
     required Uri outputDirectoryShared,
+    required Uri outputFile,
   }) {
     json[_packageNameInputKey] = packageName;
     json[_packageRootInputKey] = packageRoot.toFilePath();
+    json[_outputFileKey] = outputFile.toFilePath();
     json[_outDirInputKey] = outputDirectory.toFilePath();
     json[_outDirSharedInputKey] = outputDirectoryShared.toFilePath();
   }
@@ -121,6 +126,7 @@ sealed class HookInputBuilder {
 // TODO: Bump min-SDK constraint to 3.7 and remove once stable.
 const _buildModeInputKeyDeprecated = 'build_mode';
 const _metadataConfigKey = 'metadata';
+const _outputFileKey = 'out_file';
 const _outDirInputKey = 'out_dir';
 const _outDirSharedInputKey = 'out_dir_shared';
 const _packageNameInputKey = 'package_name';
@@ -133,8 +139,13 @@ const _configKey = 'config';
 final class BuildInput extends HookInput {
   final Map<String, Metadata> metadata;
 
+  @override
+  final Uri outputFile;
+
   BuildInput(super.json)
-      : metadata = {
+      : outputFile = json.optionalPath(_outputFileKey) ??
+            json.path(_outDirInputKey).resolve('build_output.json'),
+        metadata = {
           for (final entry
               in (json.optionalMap(_dependencyMetadataKey) ?? {}).entries)
             entry.key: Metadata.fromJson(as<Map<String, Object?>>(entry.value)),
@@ -204,8 +215,13 @@ final class LinkInput extends HookInput {
 
   final Uri? recordedUsagesFile;
 
+  @override
+  final Uri outputFile;
+
   LinkInput(super.json)
-      : _encodedAssets =
+      : outputFile = json.optionalPath(_outputFileKey) ??
+            json.path(_outDirInputKey).resolve('link_output.json'),
+        _encodedAssets =
             _parseAssets(json.getOptional<List<Object?>>(_assetsKey)),
         recordedUsagesFile = json.optionalPath(_recordedUsagesFileInputKey);
 
@@ -578,7 +594,7 @@ extension type EncodedAssetLinkOutputBuilder._(LinkOutputBuilder _builder) {
 ///
 /// We'll never bump the major version. Removing old keys from the input and
 /// output is done via modifying [latestParsableVersion].
-final latestVersion = Version(1, 7, 0);
+final latestVersion = Version(1, 8, 0);
 
 /// The parser can deal with inputs and outputs down to this version.
 ///

pkgs/native_assets_cli/lib/src/model/build_config_CHANGELOG.md

@@ -1,3 +1,17 @@
+## 1.8.0
+
+- Add `BuildInput.outputFile` to specify the outfile. This means the out file 
+  can be outside the `outputDirectory` and avoid potential conflicts.
+  Compatibility with older hooks: If the file doesn't exist, try the previous
+  location.
+  Compatibility with older SDKs: Default the location to where it was.
+
+## 1.7.0
+
+- Complete rewrite of JSON
+  Compatibility with older hooks: also emit old structure.
+  Compatibility with older SDKs: keep parsing old structure.
+
 ## 1.6.0
 
 - `BuildConfig.supportedAssetTypes` renamed to `BuildConfig.buildAssetTypes`.

pkgs/native_assets_cli/lib/src/model/hook.dart

@@ -16,5 +16,6 @@ enum Hook {
 
   String get scriptName => '$_scriptName.dart';
 
-  String get outputName => '${_scriptName}_output.json';
+  @Deprecated('Use HookInput.outputFile instead.')
+  String get outputNameDeprecated => '${_scriptName}_output.json';
 }

pkgs/native_assets_cli/lib/test.dart

@@ -9,7 +9,6 @@ import 'dart:io';
 import 'package:yaml/yaml.dart';
 
 import 'native_assets_cli_builder.dart';
-import 'native_assets_cli_internal.dart' show Hook;
 import 'src/validation.dart';
 
 export 'native_assets_cli_builder.dart';
@@ -41,6 +40,7 @@ Future<void> testBuildHook({
         Directory(await tempDir.resolveSymbolicLinks()).uri.normalizePath();
     final outputDirectory = tempUri.resolve('output/');
     final outputDirectoryShared = tempUri.resolve('output_shared/');
+    final outputFile = tempUri.resolve('output.json');
 
     await Directory.fromUri(outputDirectory).create();
     await Directory.fromUri(outputDirectoryShared).create();
@@ -50,6 +50,7 @@ Future<void> testBuildHook({
       ..setupShared(
         packageRoot: Directory.current.uri,
         packageName: _readPackageNameFromPubspec(),
+        outputFile: outputFile,
         outputDirectory: outputDirectory,
         outputDirectoryShared: outputDirectoryShared,
       )
@@ -61,11 +62,10 @@ Future<void> testBuildHook({
 
     final input = BuildInput(inputBuilder.json);
 
-    final inputUri = tempUri.resolve(Hook.build.outputName);
+    final inputUri = tempUri.resolve('input.json');
     _writeJsonTo(inputUri, input.json);
     await mainMethod(['--config=${inputUri.toFilePath()}']);
-    final output = BuildOutput(
-        _readJsonFrom(input.outputDirectory.resolve(Hook.build.outputName)));
+    final output = BuildOutput(_readJsonFrom(input.outputFile));
 
     // Test conformance of protocol invariants.
     final validationErrors = await validateBuildOutput(input, output);