Issue 39028. Guard against mixin constructor in FieldFormalParameter completion.

scheglov · commit-bot@chromium.org · commit 3a17bebf9c9a · 2019-11-18T15:36:48.000Z
R=brianwilkerson@google.com Bug: #39028 Change-Id: I78e4df6baa8424231aeb2c8044d9cb5c685dcdbe Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/125524 Reviewed-by: Brian Wilkerson <brianwilkerson@google.com> Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analysis_server/lib/src/services/completion/dart/field_formal_contributor.dart b/pkg/analysis_server/lib/src/services/completion/dart/field_formal_contributor.dart
@@ -25,17 +25,14 @@ class FieldFormalContributor extends DartCompletionContributor {
       return const <CompletionSuggestion>[];
     }
 
-    // If this is a constructor declaration
-    // then compute fields already referenced
-    ConstructorDeclaration constructorDecl =
-        node.thisOrAncestorOfType<ConstructorDeclaration>();
-    if (constructorDecl == null) {
+    ConstructorDeclaration constructor = node.thisOrAncestorOfType();
+    if (constructor == null) {
       return const <CompletionSuggestion>[];
     }
 
     // Compute the list of fields already referenced in the constructor
     List<String> referencedFields = new List<String>();
-    for (FormalParameter param in constructorDecl.parameters.parameters) {
+    for (FormalParameter param in constructor.parameters.parameters) {
       if (param is DefaultFormalParameter &&
           param.parameter is FieldFormalParameter) {
         param = (param as DefaultFormalParameter).parameter;
@@ -51,11 +48,14 @@ class FieldFormalContributor extends DartCompletionContributor {
       }
     }
 
+    ClassDeclaration class_ = constructor.thisOrAncestorOfType();
+    if (class_ == null) {
+      return const <CompletionSuggestion>[];
+    }
+
     // Add suggestions for fields that are not already referenced
-    ClassDeclaration classDecl =
-        constructorDecl.thisOrAncestorOfType<ClassDeclaration>();
     List<CompletionSuggestion> suggestions = <CompletionSuggestion>[];
-    for (ClassMember member in classDecl.members) {
+    for (ClassMember member in class_.members) {
       if (member is FieldDeclaration && !member.isStatic) {
         for (VariableDeclaration varDecl in member.fields.variables) {
           SimpleIdentifier fieldId = varDecl.name;
diff --git a/pkg/analysis_server/test/services/completion/dart/field_formal_contributor_test.dart b/pkg/analysis_server/test/services/completion/dart/field_formal_contributor_test.dart
@@ -22,6 +22,17 @@ class FieldFormalContributorTest extends DartCompletionContributorTest {
     return new FieldFormalContributor();
   }
 
+  /// https://github.com/dart-lang/sdk/issues/39028
+  test_mixin_constructor() async {
+    addTestSource('''
+mixin M {
+  M(this.^);
+}
+''');
+    await computeSuggestions();
+    expect(suggestions, isEmpty);
+  }
+
   test_ThisExpression_constructor_param() async {
     // SimpleIdentifier  FieldFormalParameter  FormalParameterList
     addTestSource('''
