fix(dart_frog_cli): avoid overwriting pubspec_overrides.yaml in dart_frog build

bricks/dart_frog_prod_server/hooks/lib/dart_frog_prod_server_hooks.dart

@@ -10,6 +10,7 @@ export 'src/get_package_graph.dart';
 export 'src/get_pubspec_lock.dart';
 export 'src/get_workspace_root.dart';
 export 'src/package_graph/package_graph.dart';
+export 'src/path_dependency.dart';
 export 'src/uses_workspace_resolution.dart';
 
 /// A void callback function (e.g. `void Function()`).

bricks/dart_frog_prod_server/hooks/lib/src/create_external_packages_folder.dart

@@ -27,13 +27,13 @@ Future<List<String>> createExternalPackagesFolder({
           final isExternal = !pathResolver.isWithin('', pathDescription.path);
           if (!isExternal) return null;
 
-          return _ExternalPathDependency(
+          return ExternalPathDependency(
             name: dependency.name,
             path: path.join(projectDirectory.path, pathDescription.path),
           );
         },
       )
-      .whereType<_ExternalPathDependency>()
+      .whereType<ExternalPathDependency>()
       .toList();
 
   if (externalPathDependencies.isEmpty) return [];
@@ -63,59 +63,13 @@ Future<List<String>> createExternalPackagesFolder({
     ),
   );
 
-  File(
-    pathResolver.join(buildDirectory.path, 'pubspec_overrides.yaml'),
-  ).writeAsStringSync(
-    '''
-resolution: null
-dependency_overrides:
-${copiedExternalPathDependencies.map(
-      (dependency) {
-        final name = dependency.name;
-        final path =
-            pathResolver.relative(dependency.path, from: buildDirectory.path);
-        return '  $name:\n    path: $path';
-      },
-    ).join('\n')}
-''',
+  overrideResolutionInPubspecOverrides(buildDirectory.path);
+  writePathDependencyOverrides(
+    projectDirectory: buildDirectory.path,
+    pathDependencies: copiedExternalPathDependencies,
   );
 
   return copiedExternalPathDependencies
       .map((dependency) => dependency.path)
       .toList();
 }
-
-/// {@template external_path_dependency}
-/// A path dependency that is not within the bundled Dart Frog project
-/// directory.
-///
-/// For example:
-/// ```yaml
-/// name: my_dart_frog_project
-/// dependencies:
-///   my_package:
-///     path: ../my_package
-/// ```
-/// {@endtemplate}
-class _ExternalPathDependency {
-  /// {@macro external_path_dependency}
-  const _ExternalPathDependency({
-    required this.name,
-    required this.path,
-  });
-
-  /// The name of the package.
-  final String name;
-
-  /// The absolute path to the package.
-  final String path;
-
-  /// Copies the [_ExternalPathDependency] to [targetDirectory].
-  Future<_ExternalPathDependency> copyTo({
-    required Directory targetDirectory,
-    CopyPath copyPath = io.copyPath,
-  }) async {
-    await copyPath(path, targetDirectory.path);
-    return _ExternalPathDependency(name: name, path: targetDirectory.path);
-  }
-}

bricks/dart_frog_prod_server/hooks/lib/src/disable_workspace_resolution.dart

@@ -86,9 +86,9 @@ void overridePathDependenciesInPubspecOverrides({
     packageGraph: packageGraph,
   );
 
-  final pathDependencies = packageConfig.packages.where(
-    (package) => package.relativeRoot && productionDeps.contains(package.name),
-  );
+  final pathDependencies = packageConfig.packages
+      .where((p) => p.relativeRoot && productionDeps.contains(p.name))
+      .map((p) => PathDependency(name: p.name, path: p.root.path));
 
   writePathDependencyOverrides(
     projectDirectory: projectDirectory,
@@ -98,7 +98,7 @@ void overridePathDependenciesInPubspecOverrides({
 
 void writePathDependencyOverrides({
   required String projectDirectory,
-  required Iterable<Package> pathDependencies,
+  required Iterable<PathDependency> pathDependencies,
 }) {
   final pubspecOverridesFile = File(
     path.join(projectDirectory, 'pubspec_overrides.yaml'),
@@ -112,7 +112,7 @@ void writePathDependencyOverrides({
   for (final package in pathDependencies) {
     editor.update(
       ['dependency_overrides', package.name],
-      {'path': path.relative(package.root.path, from: projectDirectory)},
+      {'path': path.relative(package.path, from: projectDirectory)},
     );
   }
   pubspecOverridesFile.writeAsStringSync(editor.toString());

bricks/dart_frog_prod_server/hooks/lib/src/path_dependency.dart

@@ -0,0 +1,52 @@
+import 'dart:io';
+
+import 'package:dart_frog_prod_server_hooks/dart_frog_prod_server_hooks.dart';
+import 'package:io/io.dart' as io;
+
+/// {@template path_dependency}
+/// A path dependency that the Dart Frog project relies on.
+///
+/// For example:
+/// ```yaml
+/// name: my_dart_frog_project
+/// dependencies:
+///   my_package:
+///     path: ./my_package
+/// ```
+/// {@endtemplate}
+class PathDependency {
+  /// {@macro path_dependency}
+  const PathDependency({required this.name, required this.path});
+
+  /// The name of the package.
+  final String name;
+
+  /// The absolute path to the package.
+  final String path;
+}
+
+/// {@template external_path_dependency}
+/// A path dependency that is not within the bundled Dart Frog project
+/// directory.
+///
+/// For example:
+/// ```yaml
+/// name: my_dart_frog_project
+/// dependencies:
+///   my_package:
+///     path: ../my_package
+/// ```
+/// {@endtemplate}
+class ExternalPathDependency extends PathDependency {
+  /// {@macro external_path_dependency}
+  const ExternalPathDependency({required super.name, required super.path});
+
+  /// Copies the [ExternalPathDependency] to [targetDirectory].
+  Future<ExternalPathDependency> copyTo({
+    required Directory targetDirectory,
+    CopyPath copyPath = io.copyPath,
+  }) async {
+    await copyPath(path, targetDirectory.path);
+    return ExternalPathDependency(name: name, path: targetDirectory.path);
+  }
+}

bricks/dart_frog_prod_server/hooks/test/src/create_external_packages_folder_test.dart

@@ -75,5 +75,51 @@ void main() {
       );
       expect(copyCalls, ['$from -> $to']);
     });
+
+    test("doesn't overwrite existing overrides", () async {
+      const existingOverrides = '''
+dependency_overrides:
+  dart_frog:
+    git:
+      url: https://github.com/dart-frog-dev/dart_frog
+      path: packages/dart_frog
+''';
+      final projectDirectory = Directory.systemTemp.createTempSync();
+      File(
+        path.join(projectDirectory.path, 'build', 'pubspec_overrides.yaml'),
+      )
+        ..createSync(recursive: true)
+        ..writeAsStringSync(existingOverrides);
+      File(
+        path.join(projectDirectory.path, 'pubspec.lock'),
+      ).writeAsStringSync(fooPathWithInternalDependency);
+      final copyCalls = <String>[];
+
+      await createExternalPackagesFolder(
+        projectDirectory: projectDirectory,
+        buildDirectory: Directory(path.join(projectDirectory.path, 'build')),
+        copyPath: (from, to) async {
+          copyCalls.add('$from -> $to');
+          File(
+            path.join(to, 'pubspec_overrides.yaml'),
+          ).createSync(recursive: true);
+        },
+      );
+
+      final from = path.join(projectDirectory.path, '../../foo');
+      final to = path.join(
+        projectDirectory.path,
+        'build',
+        '.dart_frog_path_dependencies',
+        'foo',
+      );
+      expect(copyCalls, ['$from -> $to']);
+      expect(
+        File(
+          path.join(projectDirectory.path, 'build', 'pubspec_overrides.yaml'),
+        ).readAsStringSync(),
+        contains(existingOverrides),
+      );
+    });
   });
 }