New customPath parameter with test

packages/custom_lint_core/lib/src/change_reporter.dart

@@ -65,9 +65,13 @@ abstract class ChangeBuilder {
   ///
   /// The builder passed to the [buildFileEdit] function has additional support
   /// for working with Dart source files.
+  ///
+  /// Use the [customPath] if the collection of edits should be written to another
+  /// dart file.
   void addDartFileEdit(
     void Function(DartFileEditBuilder builder) buildFileEdit, {
     ImportPrefixGenerator importPrefixGenerator,
+    String? customPath,
   });
 
   /// Use the [buildFileEdit] function to create a collection of edits to the
@@ -76,18 +80,26 @@ abstract class ChangeBuilder {
   ///
   /// The builder passed to the [buildFileEdit] function has no special support
   /// for any particular kind of file.
+  ///
+  /// Use the [customPath] if the collection of edits should be written to another
+  /// file.
   void addGenericFileEdit(
-    void Function(analyzer_plugin.FileEditBuilder builder) buildFileEdit,
-  );
+    void Function(analyzer_plugin.FileEditBuilder builder) buildFileEdit, {
+    String? customPath,
+  });
 
   /// Use the [buildFileEdit] function to create a collection of edits to the
   /// currently analyzed file. The edits will be added to the source change
   /// that is being built.
   ///
   /// The builder passed to the [buildFileEdit] function has additional support
   /// for working with YAML source files.
+  ///
+  /// Use the [customPath] if the collection of edits should be written to another
+  /// YAML file.
   void addYamlFileEdit(
     void Function(YamlFileEditBuilder builder) buildFileEdit,
+    String? customPath,
   );
 }
 
@@ -110,12 +122,16 @@ class _ChangeBuilderImpl implements ChangeBuilder {
   void addDartFileEdit(
     void Function(DartFileEditBuilder builder) buildFileEdit, {
     ImportPrefixGenerator? importPrefixGenerator,
+    String? customPath,
   }) {
     _operations.add(
       importPrefixGenerator == null
-          ? _innerChangeBuilder.addDartFileEdit(path, buildFileEdit)
+          ? _innerChangeBuilder.addDartFileEdit(
+              customPath ?? path,
+              buildFileEdit,
+            )
           : _innerChangeBuilder.addDartFileEdit(
-              path,
+              customPath ?? path,
               buildFileEdit,
               importPrefixGenerator: importPrefixGenerator,
             ),
@@ -124,19 +140,21 @@ class _ChangeBuilderImpl implements ChangeBuilder {
 
   @override
   void addGenericFileEdit(
-    void Function(analyzer_plugin.FileEditBuilder builder) buildFileEdit,
-  ) {
+    void Function(analyzer_plugin.FileEditBuilder builder) buildFileEdit, {
+    String? customPath,
+  }) {
     _operations.add(
-      _innerChangeBuilder.addGenericFileEdit(path, buildFileEdit),
+      _innerChangeBuilder.addGenericFileEdit(customPath ?? path, buildFileEdit),
     );
   }
 
   @override
   void addYamlFileEdit(
     void Function(YamlFileEditBuilder builder) buildFileEdit,
+    String? customPath,
   ) {
     _operations.add(
-      _innerChangeBuilder.addYamlFileEdit(path, buildFileEdit),
+      _innerChangeBuilder.addYamlFileEdit(customPath ?? path, buildFileEdit),
     );
   }
 

packages/custom_lint_core/test/assist_test.dart

@@ -4,6 +4,7 @@ import 'dart:io';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/analysis/utilities.dart';
 import 'package:analyzer/source/source_range.dart';
+import 'package:analyzer_plugin/protocol/protocol_generated.dart';
 import 'package:custom_lint_core/src/assist.dart';
 import 'package:custom_lint_core/src/change_reporter.dart';
 import 'package:custom_lint_core/src/lint_rule.dart';
@@ -58,6 +59,50 @@ void main() {
     );
   });
 
+  // Extract the name of the changed file and makes the test failing if the internal structure is not the expected one
+  String _extractFileName(PrioritizedSourceChange change) {
+    final map = change.toJson();
+
+    expect(map.containsKey('change'), true);
+    final changes = map['change']! as Map;
+
+    expect(changes.containsKey('edits'), true);
+    final edits = changes['edits']! as List;
+
+    expect(edits.length, 1);
+    final edit = edits[0]! as Map;
+
+    expect(edit.containsKey('file'), true);
+    final fileName = edit['file'] as String;
+
+    return fileName;
+  }
+
+  test('CustomAssist.testRun', () async {
+    final assist1 = MyCustomAssist('CustomAssist', 'custom_1.txt');
+    final assist2 = MyCustomAssist('AnotherCustom', 'custom_2.txt');
+
+    final file = writeToTemporaryFile('''
+void main() {
+  print('Custom world');
+}
+''');
+    final result = await resolveFile2(path: file.path);
+    result as ResolvedUnitResult;
+
+    final changeList1 = await assist1.testRun(result, SourceRange.EMPTY);
+    final changeList2 = await assist2.testRun(result, SourceRange.EMPTY);
+
+    final change1 = changeList1[0];
+    final change2 = changeList2[0];
+
+    final file1 = _extractFileName(change1);
+    final file2 = _extractFileName(change2);
+
+    expect(file1, 'custom_1.txt');
+    expect(file2, 'custom_2.txt');
+  });
+
   test('Assist.testAnalyzeAndRun', () async {
     final assist = MyAssist('MyAssist');
     final assist2 = MyAssist('Another');
@@ -115,3 +160,32 @@ class MyAssist extends DartAssist {
     });
   }
 }
+
+class MyCustomAssist extends DartAssist {
+  MyCustomAssist(this.name, this.customPath);
+
+  final String name;
+  final String customPath;
+
+  @override
+  void run(
+    CustomLintResolver resolver,
+    ChangeReporter reporter,
+    CustomLintContext context,
+    SourceRange target,
+  ) {
+    context.registry.addMethodInvocation((node) {
+      final changebuilder = reporter.createChangeBuilder(
+        message: name,
+        priority: 1,
+      );
+
+      changebuilder.addGenericFileEdit(
+        (builder) {
+          builder.addSimpleInsertion(node.offset, 'Custom 2023');
+        },
+        customPath: customPath,
+      );
+    });
+  }
+}