When target requires a function, propose a function reference, not an invocation

pkg/analysis_server/test/services/completion/completion_target_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.target;
 
 import 'package:analysis_server/src/services/completion/completion_target.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:unittest/unittest.dart';
 
 import '../../abstract_context.dart';
 import '../../reflective_tests.dart';
 
 main() {
   groupSep = ' | ';
   runReflectiveTests(CompletionTargetTest);
 }
 
 @reflectiveTest
 class CompletionTargetTest extends AbstractContextTest {
+  Source testSource;
   int completionOffset;
   CompletionTarget target;
 
   void addTestSource(String content) {
     expect(completionOffset, isNull, reason: 'Call addTestSource exactly once');
     completionOffset = content.indexOf('^');
     expect(completionOffset, isNot(equals(-1)), reason: 'missing ^');
     int nextOffset = content.indexOf('^', completionOffset + 1);
     expect(nextOffset, equals(-1), reason: 'too many ^');
     content = content.substring(0, completionOffset) +
         content.substring(completionOffset + 1);
-    Source testSource = addSource('/test.dart', content);
+    testSource = addSource('/test.dart', content);
     CompilationUnit unit = context.parseCompilationUnit(testSource);
     target = new CompletionTarget.forOffset(unit, completionOffset);
   }
 
+  void assertTarget(entityText, nodeText,
+      {int argIndex: null, bool isFunctionalArgument: false}) {
+    void assertCommon() {
+      expect(target.entity.toString(), entityText);
+      expect(target.containingNode.toString(), nodeText);
+      expect(target.argIndex, argIndex);
+    }
+    // Assert with parsed unit
+    assertCommon();
+    CompilationUnit unit =
+        context.resolveCompilationUnit2(testSource, testSource);
+    target = new CompletionTarget.forOffset(unit, completionOffset);
+    // Assert more with resolved unit
+    assertCommon();
+    expect(target.isFunctionalArgument(), isFunctionalArgument);
+  }
+
+  test_ArgumentList_InstanceCreationExpression() {
+    // ArgumentList  InstanceCreationExpression  Block
+    addTestSource('main() {new Foo(^)}');
+    assertTarget(')', '()', argIndex: 0);
+  }
+
+  test_ArgumentList_MethodInvocation() {
+    // ArgumentList  MethodInvocation  Block
+    addTestSource('main() {foo(^)}');
+    assertTarget(')', '()', argIndex: 0);
+  }
+
+  test_ArgumentList_MethodInvocation2() {
+    // ArgumentList  MethodInvocation  Block
+    addTestSource('main() {foo(^n)}');
+    assertTarget('n', '(n)', argIndex: 0);
+  }
+
+  test_ArgumentList_MethodInvocation3() {
+    // ArgumentList  MethodInvocation  Block
+    addTestSource('main() {foo(n^)}');
+    assertTarget('n', '(n)', argIndex: 0);
+  }
+
+  test_ArgumentList_MethodInvocation4() {
+    // ArgumentList  MethodInvocation  Block
+    addTestSource('main() {foo(n,^)}');
+    assertTarget('', '(n, )', argIndex: 1);
+  }
+
+  test_ArgumentList_MethodInvocation_functionArg() {
+    // ArgumentList  MethodInvocation  Block
+    addTestSource('main() {foo(^)} foo(f()) {}');
+    assertTarget(')', '()', argIndex: 0, isFunctionalArgument: true);
+  }
+
+  test_ArgumentList_MethodInvocation_functionArg2() {
+    // ArgumentList  MethodInvocation  Block
+    addTestSource('main() {new B().boo(^)} class B{boo(f()){}}');
+    assertTarget(')', '()', argIndex: 0, isFunctionalArgument: true);
+  }
+
+  test_ArgumentList_InstanceCreationExpression_functionArg2() {
+    // ArgumentList  InstanceCreationExpression  Block
+    addTestSource('main() {new B(^)} class B{B(f()){}}');
+    assertTarget(')', '()', argIndex: 0, isFunctionalArgument: true);
+  }
+
   test_AsExpression_identifier() {
     // SimpleIdentifier  TypeName  AsExpression
     addTestSource('class A {var b; X _c; foo() {var a; (a^ as String).foo();}');
-    expect(target.entity.toString(), 'a as String');
-    expect(target.containingNode.toString(), '(a as String)');
+    assertTarget('a as String', '(a as String)');
   }
 
   test_AsExpression_keyword() {
     // SimpleIdentifier  TypeName  AsExpression
     addTestSource('class A {var b; X _c; foo() {var a; (a ^as String).foo();}');
-    expect(target.entity.toString(), 'as');
-    expect(target.containingNode.toString(), 'a as String');
+    assertTarget('as', 'a as String');
   }
 
   test_AsExpression_keyword2() {
     // SimpleIdentifier  TypeName  AsExpression
     addTestSource('class A {var b; X _c; foo() {var a; (a a^s String).foo();}');
-    expect(target.entity.toString(), 'as');
-    expect(target.containingNode.toString(), 'a as String');
+    assertTarget('as', 'a as String');
   }
 
   test_AsExpression_keyword3() {
     // SimpleIdentifier  TypeName  AsExpression
     addTestSource('class A {var b; X _c; foo() {var a; (a as^ String).foo();}');
-    expect(target.entity.toString(), 'as');
-    expect(target.containingNode.toString(), 'a as String');
+    assertTarget('as', 'a as String');
   }
 
   test_AsExpression_type() {
     // SimpleIdentifier  TypeName  AsExpression
     addTestSource('class A {var b; X _c; foo() {var a; (a as ^String).foo();}');
-    expect(target.entity.toString(), 'String');
-    expect(target.containingNode.toString(), 'a as String');
+    assertTarget('String', 'a as String');
+  }
+
+  test_Block() {
+    // Block
+    addTestSource('main() {^}');
+    assertTarget('}', '{}');
+  }
+
+  test_InstanceCreationExpression_identifier() {
+    // InstanceCreationExpression  ExpressionStatement  Block
+    addTestSource('class C {foo(){var f; {var x;} new ^C();}}');
+    assertTarget('C', 'new C()');
   }
 
   test_InstanceCreationExpression_keyword() {
     // InstanceCreationExpression  ExpressionStatement  Block
     addTestSource('class C {foo(){var f; {var x;} new^ }}');
-    expect(target.entity.toString(), 'new ();');
-    expect(target.containingNode.toString(), '{var f; {var x;} new ();}');
+    assertTarget('new ();', '{var f; {var x;} new ();}');
   }
 
   test_InstanceCreationExpression_keyword2() {
     // InstanceCreationExpression  ExpressionStatement  Block
     addTestSource('class C {foo(){var f; {var x;} new^ C();}}');
-    expect(target.entity.toString(), 'new C();');
-    expect(target.containingNode.toString(), '{var f; {var x;} new C();}');
-  }
-
-  test_InstanceCreationExpression_identifier() {
-    // InstanceCreationExpression  ExpressionStatement  Block
-    addTestSource('class C {foo(){var f; {var x;} new ^C();}}');
-    expect(target.entity.toString(), 'C');
-    expect(target.containingNode.toString(), 'new C()');
+    assertTarget('new C();', '{var f; {var x;} new C();}');
   }
 
   test_VariableDeclaration_lhs_identifier_after() {
     // VariableDeclaration  VariableDeclarationList
     addTestSource('main() {int b^ = 1;}');
-    expect(target.entity.toString(), 'b = 1');
-    expect(target.containingNode.toString(), 'int b = 1');
+    assertTarget('b = 1', 'int b = 1');
   }
 
   test_VariableDeclaration_lhs_identifier_before() {
     // VariableDeclaration  VariableDeclarationList
     addTestSource('main() {int ^b = 1;}');
-    expect(target.entity.toString(), 'b = 1');
-    expect(target.containingNode.toString(), 'int b = 1');
+    assertTarget('b = 1', 'int b = 1');
   }
 }