more edge case fixes

Author: felangel

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

@@ -2,10 +2,13 @@ import 'dart:io';
 import 'package:mason/mason.dart';
 import 'package:path/path.dart' as path;
 import 'package:yaml/yaml.dart';
+import 'package:yaml_edit/yaml_edit.dart';
 
 /// A void callback function (e.g. `void Function()`).
 typedef VoidCallback = void Function();
 
+void _noop() {}
+
 /// Opts out of dart workspaces until we can generate per package lockfiles.
 /// https://github.com/dart-lang/pub/issues/4594
 VoidCallback disableWorkspaceResolution(
@@ -18,7 +21,7 @@ VoidCallback disableWorkspaceResolution(
   } on Exception catch (e) {
     context.logger.err('$e');
     exit(1);
-    return () {};
+    return _noop;
   }
 }
 
@@ -35,12 +38,15 @@ void Function() overrideResolutionInPubspecOverrides(String projectDirectory) {
   final contents = pubspecOverridesFile.readAsStringSync();
   final pubspecOverrides = loadYaml(contents) as YamlMap?;
 
-  if (pubspecOverrides?['resolution'] == 'null') return () {};
-  pubspecOverridesFile.writeAsStringSync(
-    '''
-resolution: null
-$contents''',
-  );
+  if (pubspecOverrides == null) {
+    pubspecOverridesFile.writeAsStringSync('resolution: null');
+    return () => pubspecOverridesFile.writeAsStringSync(contents);
+  }
+
+  if (pubspecOverrides['resolution'] == 'null') return _noop;
+
+  final editor = YamlEditor(contents)..update(['resolution'], null);
+  pubspecOverridesFile.writeAsStringSync(editor.toString());
 
   return () => pubspecOverridesFile.writeAsStringSync(contents);
 }

bricks/dart_frog_prod_server/hooks/pubspec.yaml

@@ -11,6 +11,7 @@ dependencies:
   mason: ^0.1.0
   path: ^1.8.1
   yaml: ^3.1.2
+  yaml_edit: ^2.2.2
 
 dev_dependencies:
   mocktail: ^1.0.0

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

@@ -70,8 +70,9 @@ dependency_overrides:
           pubspecOverrides.readAsStringSync(),
           equals(
             '''
+$originalPubspecOverridesContent
 resolution: null
-$originalPubspecOverridesContent''',
+''',
           ),
         );
       });