From 91c05b2bbbc22753e548e528f20f90e1e7b6afb4 Mon Sep 17 00:00:00 2001
From: Danny Tuppeny <danny@tuppeny.com>
Date: Mon, 2 Dec 2024 18:26:34 +0000
Subject: [PATCH] [analysis_server] Use generic function syntax for function
 parameters in "Extract Method"

This fixes an issue where parameters that used the new function syntax and had no parameter names would produce code like `void f(String )` where the type would be interpreted as a parameter name and typed `dynamic`.

Fixes https://github.com/Dart-Code/Dart-Code/issues/5350

Change-Id: Ifcbe64dadb88cc0fd9b4fa3637045bcdc343f3f7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/397900
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Commit-Queue: Brian Wilkerson <brianwilkerson@google.com>
---
 .../refactoring/legacy/extract_method.dart    | 12 +++--
 .../legacy/extract_method_test.dart           | 49 ++++++++++++++++++-
 2 files changed, 56 insertions(+), 5 deletions(-)

diff --git a/pkg/analysis_server/lib/src/services/refactoring/legacy/extract_method.dart b/pkg/analysis_server/lib/src/services/refactoring/legacy/extract_method.dart
index 1b5ca5cebea9..d7c2e17213b6 100644
--- a/pkg/analysis_server/lib/src/services/refactoring/legacy/extract_method.dart
+++ b/pkg/analysis_server/lib/src/services/refactoring/legacy/extract_method.dart
@@ -353,12 +353,14 @@ final class ExtractMethodRefactoringImpl extends RefactoringImpl
             sb.write(' ');
           }
         }
-        // name
-        sb.write(parameter.name);
         // optional function-typed parameter parameters
         if (parameter.parameters != null) {
+          sb.write('Function');
           sb.write(parameter.parameters);
+          sb.write(' ');
         }
+        // name
+        sb.write(parameter.name);
       }
       sb.write(')');
     }
@@ -1849,8 +1851,10 @@ extension on LibraryElement {
           parametersBuffer.write(', ');
         }
         parametersBuffer.write(parameterType);
-        parametersBuffer.write(' ');
-        parametersBuffer.write(parameter.name);
+        if (parameter.name.isNotEmpty) {
+          parametersBuffer.write(' ');
+          parametersBuffer.write(parameter.name);
+        }
       }
       parametersBuffer.write(')');
       return getTypeSource(type.returnType, librariesToImport);
diff --git a/pkg/analysis_server/test/services/refactoring/legacy/extract_method_test.dart b/pkg/analysis_server/test/services/refactoring/legacy/extract_method_test.dart
index cfa809a5ca4d..95ee7323b85c 100644
--- a/pkg/analysis_server/test/services/refactoring/legacy/extract_method_test.dart
+++ b/pkg/analysis_server/test/services/refactoring/legacy/extract_method_test.dart
@@ -3377,7 +3377,7 @@ class C {
     return d;
   }
 
-  int res(int callback(int x, int y), int b) {
+  int res(int Function(int x, int y) callback, int b) {
     int c = callback(b, 2);
     return c;
   }
@@ -3604,6 +3604,53 @@ int res() {
 ''');
   }
 
+  Future<void> test_statements_topFunction_parameters_function() async {
+    await indexTestUnit('''
+Future<void> f(void f(String x), String a) async {
+// start
+  f(a);
+// end
+}
+''');
+    _createRefactoringForStartEndComments();
+    // apply refactoring
+    return _assertSuccessfulRefactoring('''
+Future<void> f(void f(String x), String a) async {
+// start
+  res(f, a);
+// end
+}
+
+void res(void Function(String x) f, String a) {
+  f(a);
+}
+''');
+  }
+
+  Future<void>
+  test_statements_topFunction_parameters_function_functionSyntax() async {
+    await indexTestUnit('''
+Future<void> f(void Function(String) f, String a) async {
+// start
+  f(a);
+// end
+}
+''');
+    _createRefactoringForStartEndComments();
+    // apply refactoring
+    return _assertSuccessfulRefactoring('''
+Future<void> f(void Function(String) f, String a) async {
+// start
+  res(f, a);
+// end
+}
+
+void res(void Function(String) f, String a) {
+  f(a);
+}
+''');
+  }
+
   Future<void> test_statements_topFunction_parameters_recordType() async {
     await indexTestUnit('''
 void f((int, String) r) {