fix generic function expressions, part of #25175

pkg/analyzer/test/generated/resolver_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 analyzer.test.generated.resolver_test;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
@@ skipping 13025 matching lines @@
   /*=T*/ f/*<T>*/(/*=T*/ e) => null;
   static /*=T*/ g/*<T>*/(/*=T*/ e) => null;
   static final h = g;
 }
 
 /*=T*/ topF/*<T>*/(/*=T*/ e) => null;
 var topG = topF;
 void test/*<S>*/(/*=T*/ pf/*<T>*/(/*=T*/ e)) {
   var c = new C<int>();
   /*=T*/ lf/*<T>*/(/*=T*/ e) => null;
+
+  var lambdaCall = (/*<E>*/(/*=E*/ e) => e)/*<int>*/(3);
   var methodCall = (c.f)/*<int>*/(3);
   var staticCall = (C.g)/*<int>*/(3);
   var staticFieldCall = (C.h)/*<int>*/(3);
   var topFunCall = (topF)/*<int>*/(3);
   var topFieldCall = (topG)/*<int>*/(3);
   var localCall = (lf)/*<int>*/(3);
   var paramCall = (pf)/*<int>*/(3);
 }
 ''');
     expect(_findIdentifier('methodCall').staticType.toString(), "int");
     expect(_findIdentifier('staticCall').staticType.toString(), "int");
     expect(_findIdentifier('staticFieldCall').staticType.toString(), "int");
     expect(_findIdentifier('topFunCall').staticType.toString(), "int");
     expect(_findIdentifier('topFieldCall').staticType.toString(), "int");
     expect(_findIdentifier('localCall').staticType.toString(), "int");
     expect(_findIdentifier('paramCall').staticType.toString(), "int");
+    expect(_findIdentifier('lambdaCall').staticType.toString(), "int");
   }
 
   void fail_genericMethod_functionExpressionInvocation_inferred() {
     _resolveTestUnit(r'''
 class C<E> {
   /*=T*/ f/*<T>*/(/*=T*/ e) => null;
   static /*=T*/ g/*<T>*/(/*=T*/ e) => null;
   static final h = g;
 }
 
 /*=T*/ topF/*<T>*/(/*=T*/ e) => null;
 var topG = topF;
 void test/*<S>*/(/*=T*/ pf/*<T>*/(/*=T*/ e)) {
   var c = new C<int>();
   /*=T*/ lf/*<T>*/(/*=T*/ e) => null;
+
+  var lambdaCall = (/*<E>*/(/*=E*/ e) => e)(3);
   var methodCall = (c.f)(3);
   var staticCall = (C.g)(3);
   var staticFieldCall = (C.h)(3);
   var topFunCall = (topF)(3);
   var topFieldCall = (topG)(3);
   var localCall = (lf)(3);
   var paramCall = (pf)(3);
 }
 ''');
     expect(_findIdentifier('methodCall').staticType.toString(), "int");
     expect(_findIdentifier('staticCall').staticType.toString(), "int");
     expect(_findIdentifier('staticFieldCall').staticType.toString(), "int");
     expect(_findIdentifier('topFunCall').staticType.toString(), "int");
     expect(_findIdentifier('topFieldCall').staticType.toString(), "int");
     expect(_findIdentifier('localCall').staticType.toString(), "int");
     expect(_findIdentifier('paramCall').staticType.toString(), "int");
+    expect(_findIdentifier('lambdaCall').staticType.toString(), "int");
   }
 
   void fail_genericMethod_functionInvocation_inferred() {
     _resolveTestUnit(r'''
 class C<E> {
   /*=T*/ f/*<T>*/(/*=T*/ e) => null;
   static /*=T*/ g/*<T>*/(/*=T*/ e) => null;
   static final h = g;
 }
 
@@ skipping 3577 matching lines @@
 
   void _resolveTestUnit(String code) {
     testCode = code;
     testSource = addSource(testCode);
     LibraryElement library = resolve2(testSource);
     assertNoErrors(testSource);
     verify([testSource]);
     testUnit = resolveCompilationUnit(testSource, library);
   }
 }