Propertly summarize LUB function types.

pkg/analyzer/test/src/summary/resynthesize_test.dart

Index: pkg/analyzer/test/src/summary/resynthesize_test.dart
diff --git a/pkg/analyzer/test/src/summary/resynthesize_test.dart b/pkg/analyzer/test/src/summary/resynthesize_test.dart
index 8b1e4dd45c46111d0f37b176df389705e0e567cc..367d5b6313ffdc1e05f1f3adc34559751a221e0d 100644
--- a/pkg/analyzer/test/src/summary/resynthesize_test.dart
+++ b/pkg/analyzer/test/src/summary/resynthesize_test.dart
@@ -642,14 +642,17 @@ class ResynthTest extends ResolverTestCase {
     }
   }
 
-  void compareExecutableElements(ExecutableElement resynthesized,
-      ExecutableElement original, String desc) {
+  void compareExecutableElements(
+      ExecutableElement resynthesized, ExecutableElement original, String desc,
+      {bool shallow: false}) {
     compareElements(resynthesized, original, desc);
     compareParameterElementLists(
         resynthesized.parameters, original.parameters, desc);
     compareTypes(
         resynthesized.returnType, original.returnType, '$desc return type');
-    compareTypes(resynthesized.type, original.type, desc);
+    if (!shallow) {
+      compareTypes(resynthesized.type, original.type, desc);
+    }
     expect(resynthesized.typeParameters.length, original.typeParameters.length);
     for (int i = 0; i < resynthesized.typeParameters.length; i++) {
       compareTypeParameterElements(
@@ -704,12 +707,13 @@ class ResynthTest extends ResolverTestCase {
   }
 
   void compareFunctionElements(
-      FunctionElement resynthesized, FunctionElement original, String desc) {
+      FunctionElement resynthesized, FunctionElement original, String desc,
+      {bool shallow: false}) {
     if (original == null && resynthesized == null) {
       return;
     }
     expect(resynthesized, isNotNull, reason: desc);
-    compareExecutableElements(resynthesized, original, desc);
+    compareExecutableElements(resynthesized, original, desc, shallow: shallow);
     checkPossibleLocalElements(resynthesized, original);
   }
 
@@ -937,6 +941,15 @@ class ResynthTest extends ResolverTestCase {
         compareFunctionTypeAliasElements(
             resynthesized.element, original.element, desc);
       }
+      if (original.element.enclosingElement == null &&
+          original.element is FunctionElement) {
+        expect(resynthesized.element, new isInstanceOf<FunctionElement>());
+        expect(resynthesized.element.enclosingElement, isNull, reason: desc);
+        compareFunctionElements(
+            resynthesized.element, original.element, '$desc element',
+            shallow: true);
+        expect(resynthesized.element.type, same(resynthesized));
+      }
       expect(resynthesized.typeArguments.length, original.typeArguments.length,
           reason: desc);
       for (int i = 0; i < resynthesized.typeArguments.length; i++) {
@@ -993,8 +1006,8 @@ class ResynthTest extends ResolverTestCase {
     VariableElementImpl resynthesizedActual =
         getActualElement(resynthesized, desc);
     VariableElementImpl originalActual = getActualElement(original, desc);
-    compareFunctionElements(
-        resynthesizedActual.initializer, originalActual.initializer, desc);
+    compareFunctionElements(resynthesizedActual.initializer,
+        originalActual.initializer, '$desc initializer');
     if (originalActual is ConstVariableElement) {
       Element oEnclosing = original.enclosingElement;
       if (oEnclosing is ClassElement && oEnclosing.isEnum) {
@@ -3632,6 +3645,70 @@ void set x(value) {}''');
     checkLibrary('void set x(int value) {} set y(value) {}');
   }
 
+  test_syntheticFunctionType_genericClosure() {
+    if (!options.strongMode) {
+      // The test below uses generic comment syntax because proper generic
+      // method syntax doesn't support generic closures.  So it can only run in
+      // strong mode.
+      // TODO(paulberry): once proper generic method syntax supports generic
+      // closures, rewrite the test below without using generic comment syntax,
+      // and remove this hack.  See dartbug.com/25819
+      return;
+    }
+    checkLibrary('''
+final v = f() ? /*<T>*/(T t) => 0 : /*<T>*/(T t) => 1;
+bool f() => true;
+''');
+  }
+
+  test_syntheticFunctionType_genericClosure_inGenericFunction() {
+    if (!options.strongMode) {
+      // The test below uses generic comment syntax because proper generic
+      // method syntax doesn't support generic closures.  So it can only run in
+      // strong mode.
+      // TODO(paulberry): once proper generic method syntax supports generic
+      // closures, rewrite the test below without using generic comment syntax,
+      // and remove this hack.  See dartbug.com/25819
+      return;
+    }
+    checkLibrary('''
+void f<T, U>(bool b) {
+  final v = b ? /*<V>*/(T t, U u, V v) => 0 : /*<V>*/(T t, U u, V v) => 1;
+}
+''');
+  }
+
+  test_syntheticFunctionType_inGenericClass() {
+    checkLibrary('''
+class C<T, U> {
+  var v = f() ? (T t, U u) => 0 : (T t, U u) => 1;
+}
+bool f() => false;
+''');
+  }
+
+  test_syntheticFunctionType_inGenericFunction() {
+    checkLibrary('''
+void f<T, U>(bool b) {
+  var v = b ? (T t, U u) => 0 : (T t, U u) => 1;
+}
+''');
+  }
+
+  test_syntheticFunctionType_noArguments() {
+    checkLibrary('''
+final v = f() ? () => 0 : () => 1;
+bool f() => true;
+''');
+  }
+
+  test_syntheticFunctionType_withArguments() {
+    checkLibrary('''
+final v = f() ? (int x, String y) => 0 : (int x, String y) => 1;
+bool f() => true;
+''');
+  }
+
   test_type_arguments_explicit_dynamic_dynamic() {
     checkLibrary('Map<dynamic, dynamic> m;');
   }