analyzer: Support implicit call tearoff from type variable

Fixes #54353

Change-Id: I0b7725efb6380de35832f1a713df3b4139990f0b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/346947
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Samuel Rawlins <[email protected]>

Author: srawlins

pkg/analyzer/lib/src/generated/error_detection_helpers.dart

@@ -293,6 +293,14 @@ mixin ErrorDetectionHelpers {
   /// > is a function type or the type `Function`, `e` is treated as `e.call`.
   MethodElement? getImplicitCallMethod(
       DartType type, DartType? context, SyntacticEntity errorNode) {
+    var visitedTypes = {type};
+    while (type is TypeParameterType) {
+      type = type.bound;
+      if (!visitedTypes.add(type)) {
+        // A cycle!
+        return null;
+      }
+    }
     if (context != null &&
         typeSystem.acceptsFunctionType(context) &&
         type is InterfaceType &&

pkg/analyzer/test/src/dart/resolution/ast_rewrite_test.dart

@@ -538,6 +538,68 @@ ImplicitCallReference
     staticType: C
   staticElement: self::@class::C::@method::call
   staticType: void Function(int)
+''');
+  }
+
+  test_simpleIdentifier_typeAlias() async {
+    await assertNoErrorsInCode('''
+class A {
+  void call() {}
+}
+typedef B = A;
+Function f(B b) => b;
+''');
+
+    final node = findNode.implicitCallReference('b;');
+    assertResolvedNodeText(node, r'''
+ImplicitCallReference
+  expression: SimpleIdentifier
+    token: b
+    staticElement: self::@function::f::@parameter::b
+    staticType: A
+      alias: self::@typeAlias::B
+  staticElement: self::@class::A::@method::call
+  staticType: void Function()
+''');
+  }
+
+  test_simpleIdentifier_typeVariable() async {
+    await assertNoErrorsInCode('''
+class A {
+  void call() {}
+}
+Function f<X extends A>(X x) => x;
+''');
+
+    final node = findNode.implicitCallReference('x;');
+    assertResolvedNodeText(node, r'''
+ImplicitCallReference
+  expression: SimpleIdentifier
+    token: x
+    staticElement: self::@function::f::@parameter::x
+    staticType: X
+  staticElement: self::@class::A::@method::call
+  staticType: void Function()
+''');
+  }
+
+  test_simpleIdentifier_typeVariable2() async {
+    await assertNoErrorsInCode('''
+class A {
+  void call() {}
+}
+Function f<X extends A, Y extends X>(Y y) => y;
+''');
+
+    final node = findNode.implicitCallReference('y;');
+    assertResolvedNodeText(node, r'''
+ImplicitCallReference
+  expression: SimpleIdentifier
+    token: y
+    staticElement: self::@function::f::@parameter::y
+    staticType: Y
+  staticElement: self::@class::A::@method::call
+  staticType: void Function()
 ''');
   }
 }