From 940d7effbdab047afd0122b5d9bab6fdbbf48dd7 Mon Sep 17 00:00:00 2001
From: Konstantin Shcheglov <scheglov@google.com>
Date: Sat, 8 Aug 2020 01:22:53 +0000
Subject: [PATCH] Fix for crash in AddMissingEnumCaseClauses.

R=brianwilkerson@google.com, pquitslund@google.com

Change-Id: I0dc8c3158eb4b46247e415ff36c33991598bce9c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/157861
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
---
 .../dart/add_missing_enum_case_clauses.dart   |  4 +++
 .../add_missing_enum_case_clauses_test.dart   | 28 +++++++++++++++----
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/pkg/analysis_server/lib/src/services/correction/dart/add_missing_enum_case_clauses.dart b/pkg/analysis_server/lib/src/services/correction/dart/add_missing_enum_case_clauses.dart
index 77d58d7849e..d4426a0e717 100644
--- a/pkg/analysis_server/lib/src/services/correction/dart/add_missing_enum_case_clauses.dart
+++ b/pkg/analysis_server/lib/src/services/correction/dart/add_missing_enum_case_clauses.dart
@@ -16,7 +16,11 @@ class AddMissingEnumCaseClauses extends CorrectionProducer {
 
   @override
   Future<void> compute(ChangeBuilder builder) async {
+    if (node is! SwitchStatement) {
+      return;
+    }
     var statement = node as SwitchStatement;
+
     String enumName;
     var enumConstantNames = <String>[];
     var expressionType = statement.expression.staticType;
diff --git a/pkg/analysis_server/test/src/services/correction/fix/add_missing_enum_case_clauses_test.dart b/pkg/analysis_server/test/src/services/correction/fix/add_missing_enum_case_clauses_test.dart
index 41407c019b2..09f61edd534 100644
--- a/pkg/analysis_server/test/src/services/correction/fix/add_missing_enum_case_clauses_test.dart
+++ b/pkg/analysis_server/test/src/services/correction/fix/add_missing_enum_case_clauses_test.dart
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'package:analysis_server/src/services/correction/fix.dart';
+import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
 import 'package:test_reflective_loader/test_reflective_loader.dart';
@@ -20,17 +21,21 @@ class AddMissingEnumCaseClausesTest extends FixProcessorTest {
   @override
   FixKind get kind => DartFixKind.ADD_MISSING_ENUM_CASE_CLAUSES;
 
-  Future<void> assertHasFixWithFilter(String expected) async {
-    var noError = true;
-    await assertHasFix(expected, errorFilter: (error) {
-      if (noError &&
+  bool Function(AnalysisError) get _filter {
+    var hasError = false;
+    return (error) {
+      if (!hasError &&
           error.errorCode ==
               StaticWarningCode.MISSING_ENUM_CONSTANT_IN_SWITCH) {
-        noError = false;
+        hasError = true;
         return true;
       }
       return false;
-    });
+    };
+  }
+
+  Future<void> assertHasFixWithFilter(String expected) async {
+    await assertHasFix(expected, errorFilter: _filter);
   }
 
   Future<void> test_empty() async {
@@ -59,6 +64,17 @@ void f(E e) {
 ''');
   }
 
+  Future<void> test_incomplete_switchStatement() async {
+    await resolveTestUnit(r'''
+enum E {a, b, c}
+
+void f(E e) {
+  switch(e
+}
+''');
+    await assertNoFix(errorFilter: _filter);
+  }
+
   Future<void> test_nonEmpty() async {
     await resolveTestUnit('''
 enum E {a, b, c}