[analysis_server] Account for late keyword in convert to getter assist

Change-Id: I421ec8c9393ba1f602eee98010f9e5b6114dd7a0
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/391060
Reviewed-by: Samuel Rawlins <[email protected]>
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>

Author: parlough

pkg/analysis_server/lib/src/services/correction/dart/convert_into_getter.dart

@@ -42,7 +42,7 @@ class ConvertIntoGetter extends ResolvedCorrectionProducer {
     if (fieldDeclaration == null) {
       return;
     }
-    // The field must be final and has only one variable.
+    // The field must be final and have only one variable.
     var fieldList = fieldDeclaration.fields;
     var finalKeyword = fieldList.keyword;
     if (finalKeyword == null || fieldList.variables.length != 1) {
@@ -64,7 +64,9 @@ class ConvertIntoGetter extends ResolvedCorrectionProducer {
     code += ' ${field.name.lexeme}';
     code += ' => ${utils.getNodeText(initializer)}';
     code += ';';
-    var replacementRange = range.startEnd(finalKeyword, fieldDeclaration);
+
+    var startingKeyword = fieldList.lateKeyword ?? finalKeyword;
+    var replacementRange = range.startEnd(startingKeyword, fieldDeclaration);
     await builder.addDartFileEdit(file, (builder) {
       builder.addSimpleReplacement(replacementRange, code);
     });

pkg/analysis_server/test/src/services/correction/assist/convert_into_getter_test.dart

@@ -19,6 +19,19 @@ class ConvertIntoGetterTest extends AssistProcessorTest {
   @override
   AssistKind get kind => DartAssistKind.CONVERT_INTO_GETTER;
 
+  Future<void> test_late() async {
+    await resolveTestCode('''
+class A {
+  late final int f = 1 + 2;
+}
+''');
+    await assertHasAssistAt('f =', '''
+class A {
+  int get f => 1 + 2;
+}
+''');
+  }
+
   Future<void> test_noInitializer() async {
     verifyNoTestUnitErrors = false;
     await resolveTestCode('''