Fix exception in code completion (issue 23439)

pkg/analysis_server/test/services/completion/local_declaration_visitor_test.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library test.services.completion.local_declaration_visitor_test;
+
+import 'package:analysis_server/src/services/completion/local_declaration_visitor.dart';
+import 'package:analyzer/src/generated/ast.dart';
+import 'package:analyzer/src/generated/error.dart';
+import 'package:analyzer/src/generated/parser.dart';
+import 'package:analyzer/src/generated/scanner.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+import 'package:unittest/unittest.dart';
+
+main() {
+  groupSep = ' | ';
+  defineReflectiveTests(LocalDeclarationVisitorTest);
+}
+
+@reflectiveTest
+class LocalDeclarationVisitorTest {
+  CompilationUnit parseCompilationUnit(String source) {
+    AnalysisErrorListener listener = AnalysisErrorListener.NULL_LISTENER;
+    Scanner scanner =
+        new Scanner(null, new CharSequenceReader(source), listener);
+    Token token = scanner.tokenize();
+    Parser parser = new Parser(null, listener);
+    CompilationUnit unit = parser.parseCompilationUnit(token);
+    expect(unit, isNotNull);
+    return unit;
+  }
+
+  test_visitForEachStatement() {
+    CompilationUnit unit = parseCompilationUnit('''
+class MyClass {}
+f(List<MyClass> list) {
+  for(MyClas( x in list) {}
+}
+''');
+    NodeList<CompilationUnitMember> declarations = unit.declarations;
+    expect(declarations, hasLength(2));
+    FunctionDeclaration f = declarations[1];
+    expect(f, isNotNull);
+    BlockFunctionBody body = f.functionExpression.body;
+    Statement statement = body.block.statements[0];
+    expect(statement, new isInstanceOf<ForEachStatement>());
+    statement.accept(new TestVisitor(statement.offset));
+  }
+}
+
+class TestVisitor extends LocalDeclarationVisitor {
+  TestVisitor(int offset) : super(offset);
+
+  @override
+  void declaredClass(ClassDeclaration declaration) {}
+
+  @override
+  void declaredClassTypeAlias(ClassTypeAlias declaration) {}
+
+  @override
+  void declaredField(FieldDeclaration fieldDecl, VariableDeclaration varDecl) {}
+
+  @override
+  void declaredFunction(FunctionDeclaration declaration) {}
+
+  @override
+  void declaredFunctionTypeAlias(FunctionTypeAlias declaration) {}
+
+  @override
+  void declaredLabel(Label label, bool isCaseLabel) {}
+
+  @override
+  void declaredLocalVar(SimpleIdentifier name, TypeName type) {
+    expect(name, isNotNull);
+  }
+
+  @override
+  void declaredMethod(MethodDeclaration declaration) {}
+
+  @override
+  void declaredParam(SimpleIdentifier name, TypeName type) {}
+
+  @override
+  void declaredTopLevelVar(
+      VariableDeclarationList varList, VariableDeclaration varDecl) {}
+}