pkg/analyzer/test/src/diagnostics/ambiguous_extension_member_access_test.dart - sdk - Git at Google

 // Copyright (c) 2019, 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.

 import 'package:test_reflective_loader/test_reflective_loader.dart';

 import '../dart/resolution/context_collection_resolution.dart';
 import '../dart/resolution/node_text_expectations.dart';

 main() {
   defineReflectiveSuite(() {
     defineReflectiveTests(AmbiguousExtensionMemberAccessTest);
     defineReflectiveTests(UpdateNodeTextExpectations);
   });
 }

 @reflectiveTest
 class AmbiguousExtensionMemberAccessTest extends PubPackageResolutionTest {
   test_call() async {
     await resolveTestCodeWithDiagnostics(r'''
 class A {}

 extension E1 on A {
   int call() => 0;
 }

 extension E2 on A {
   int call() => 0;
 }

 int f(A a) => a();
 //            ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'call' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
 ''');
   }

   test_getter_getter() async {
     var result = await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int {
   void get a => 1;
 }

 extension E2 on int {
   void get a => 2;
 }

 f() {
   0.a;
 //  ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');

     var node = result.findNode.propertyAccess('0.a');
     assertResolvedNodeText(node, r'''
 PropertyAccess
   target: IntegerLiteral
     literal: 0
     staticType: int
   operator: .
   propertyName: SimpleIdentifier
     token: a
     element: <null>
     staticType: InvalidType
   staticType: InvalidType
 ''');
   }

   test_getter_getterStatic() async {
     var result = await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int {
   void get a => 1;
 }

 extension E2 on int {
   static void get a => 2;
 }

 f() {
   0.a;
 }
 ''');

     var node = result.findNode.propertyAccess('0.a');
     assertResolvedNodeText(node, r'''
 PropertyAccess
   target: IntegerLiteral
     literal: 0
     staticType: int
   operator: .
   propertyName: SimpleIdentifier
     token: a
     element: <testLibrary>::@extension::E1::@getter::a
     staticType: void
   staticType: void
 ''');
   }

   test_getter_method() async {
     var result = await resolveTestCodeWithDiagnostics(r'''
 extension E on int {
   int get a => 1;
 }

 extension E2 on int {
   void a() {}
 }

 f() {
   0.a;
 //  ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');

     var node = result.findNode.propertyAccess('0.a');
     assertResolvedNodeText(node, r'''
 PropertyAccess
   target: IntegerLiteral
     literal: 0
     staticType: int
   operator: .
   propertyName: SimpleIdentifier
     token: a
     element: <null>
     staticType: InvalidType
   staticType: InvalidType
 ''');
   }

   test_getter_setter() async {
     var result = await resolveTestCodeWithDiagnostics(r'''
 extension E on int {
   int get a => 1;
 }

 extension E2 on int {
   set a(int v) { }
 }

 f() {
   0.a;
 //  ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');

     var node = result.findNode.propertyAccess('0.a');
     assertResolvedNodeText(node, r'''
 PropertyAccess
   target: IntegerLiteral
     literal: 0
     staticType: int
   operator: .
   propertyName: SimpleIdentifier
     token: a
     element: <null>
     staticType: InvalidType
   staticType: InvalidType
 ''');
   }

   test_method_conflict_conflict_notSpecific() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int { void foo() {} }
 extension E2 on int { void foo() {} }
 extension E on int? { void foo() {} }
 void f() {
   0.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');
   }

   test_method_conflict_conflict_notSpecific_sameName() async {
     var one = getFile('$testPackageLibPath/one.dart');
     var two = getFile('$testPackageLibPath/two.dart');

     await resolveFilesWithDiagnostics({
       one: '''
 extension E on int { void foo() {} }
 //        ^
 // [context 1] E is defined in /home/test/lib/one.dart
 ''',
       two: '''
 extension E on int { void foo() {} }
 //        ^
 // [context 2] E is defined in /home/test/lib/two.dart
 ''',
       testFile: '''
 // ignore_for_file: unused_import
 import 'one.dart';
 import 'two.dart';
 void f() {
   0.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessTwo][context 1][context 2] A member named 'foo' is defined in 'extension E on int (where E is defined in /home/test/lib/one.dart)' and 'extension E on int (where E is defined in /home/test/lib/two.dart)', and neither is more specific.
 }
 ''',
     });
   }

   test_method_conflict_conflict_notSpecific_sameName_invalidType() async {
     await resolveTestCodeWithDiagnostics(r'''
 // ignore_for_file: unused_element
 void f(Iterable<void> p) {
   p.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessTwo][context 1][context 2] A member named 'foo' is defined in 'extension on Iterable<InvalidType> (where <unnamed extension> is defined in /home/test/lib/test.dart)' and 'extension on Iterable<InvalidType> (where <unnamed extension> is defined in /home/test/lib/test.dart)', and neither is more specific.
 }
 extension on Iterable<Undef1> { void foo() {} }
 // [context 1][column 1][length 0] <unnamed extension> is defined in /home/test/lib/test.dart
 //                    ^^^^^^
 // [diag.nonTypeAsTypeArgument] The name 'Undef1' isn't a type, so it can't be used as a type argument.
 extension on Iterable<Undef2> { void foo() {} }
 // [context 2][column 1][length 0] <unnamed extension> is defined in /home/test/lib/test.dart
 //                    ^^^^^^
 // [diag.nonTypeAsTypeArgument] The name 'Undef2' isn't a type, so it can't be used as a type argument.
 ''');
   }

   test_method_conflict_conflict_specific() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int? { void foo() {} }
 extension E2 on int? { void foo() {} }
 extension E on int { void foo() {} }
 void f() {
   0.foo();
 }
 ''');
   }

   test_method_conflict_notSpecific_conflict() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int { void foo() {} }
 extension E on int? { void foo() {} }
 extension E2 on int { void foo() {} }
 void f() {
   0.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');
   }

   test_method_conflict_specific_conflict() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int? { void foo() {} }
 extension E on int { void foo() {} }
 extension E2 on int? { void foo() {} }
 void f() {
   0.foo();
 }
 ''');
   }

   test_method_method() async {
     var result = await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int {
   void a() {}
 }

 extension E2 on int {
   void a() {}
 }

 f() {
   0.a();
 //  ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');

     var node = result.findNode.methodInvocation('0.a()');
     assertResolvedNodeText(node, r'''
 MethodInvocation
   target: IntegerLiteral
     literal: 0
     staticType: int
   operator: .
   methodName: SimpleIdentifier
     token: a
     element: <null>
     staticType: InvalidType
   argumentList: ArgumentList
     leftParenthesis: (
     rightParenthesis: )
   staticInvokeType: InvalidType
   staticType: InvalidType
 ''');
   }

   test_method_notSpecific_conflict_conflict() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E on int? { void foo() {} }
 extension E1 on int { void foo() {} }
 extension E2 on int { void foo() {} }
 void f() {
   0.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');
   }

   test_method_notSpecific_conflict_conflict_conflict() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E on int? { void foo() {} }
 extension E1 on int { void foo() {} }
 extension E2 on int { void foo() {} }
 extension E3 on int { void foo() {} }
 void f() {
   0.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessThreeOrMore] A member named 'foo' is defined in extension 'E1', extension 'E2', and extension 'E3', and none are more specific.
 }
 ''');
   }

   test_method_specific_conflict_conflict() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E on int { void foo() {} }
 extension E1 on int? { void foo() {} }
 extension E2 on int? { void foo() {} }
 void f() {
   0.foo();
 }
 ''');
   }

   test_method_triple_conflict_sameName() async {
     var one = getFile('$testPackageLibPath/one.dart');
     var two = getFile('$testPackageLibPath/two.dart');
     var three = getFile('$testPackageLibPath/three.dart');

     await resolveFilesWithDiagnostics({
       one: '''
 extension E on int { void foo() {} }
 //        ^
 // [context 1] E is defined in /home/test/lib/one.dart
 ''',
       two: '''
 extension E on int { void foo() {} }
 //        ^
 // [context 2] E is defined in /home/test/lib/two.dart
 ''',
       three: '''
 extension E1 on int { void foo() {} }
 ''',
       testFile: '''
 // ignore_for_file: unused_import
 import 'one.dart';
 import 'two.dart';
 import 'three.dart';
 void f() {
   0.foo();
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessThreeOrMore][context 1][context 2] A member named 'foo' is defined in extension 'E', extension 'E', and extension 'E1', and none are more specific.
 }
 ''',
     });
   }

   test_noMoreSpecificExtension() async {
     await resolveTestCodeWithDiagnostics(r'''
 class Target<T> {}

 class SubTarget<T> extends Target<T> {}

 extension E1 on SubTarget<Object> {
   int get foo => 0;
 }

 extension E2<T> on Target<T> {
   int get foo => 0;
 }

 f(SubTarget<num> t) {
   // The instantiated on type of `E1(t)` is `SubTarget<Object>`.
   // The instantiated on type of `E2(t)` is `Target<num>`.
   // Neither is a subtype of the other, so the resolution is ambiguous.
   t.foo;
 //  ^^^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on SubTarget<Object>' and 'extension E2<T> on Target<T>', and neither is more specific.
 }
 ''');
   }

   test_operator_binary() async {
     await resolveTestCodeWithDiagnostics(r'''
 class A {}

 extension E1 on A {
   A operator +(A a) => a;
 }

 extension E2 on A {
   A operator +(A a) => a;
 }

 A f(A a) => a + a;
 //          ^^^^^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named '+' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
 ''');
   }

   test_operator_binary_compoundAssignment() async {
     await resolveTestCodeWithDiagnostics(r'''
 class A {}

 extension E1 on A {
   A operator +(_) => this;
 }

 extension E2 on A {
   A operator +(_) => this;
 }

 void f(A a) {
   a += 0;
 //  ^^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named '+' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
 }
 ''');
   }

   test_operator_index_index() async {
     await resolveTestCodeWithDiagnostics(r'''
 class A {}

 extension E1 on A {
   int operator [](int i) => 0;
 }

 extension E2 on A {
   int operator [](int i) => 0;
 }

 int f(A a) => a[0];
 //            ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named '[]' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
 ''');
   }

   test_operator_index_indexEq() async {
     await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int {
   int operator[](int index) => 0;
 }

 extension E2 on int {
   void operator[]=(int index, int value) {}
 }

 f() {
   0[1] += 2;
 //^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named '[]' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');
   }

   test_operator_unary() async {
     await resolveTestCodeWithDiagnostics(r'''
 class A {}

 extension E1 on A {
   int operator -() => 0;
 }

 extension E2 on A {
   int operator -() => 0;
 }

 int f(A a) => -a;
 //             ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'unary-' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
 ''');
   }

   test_setter_setter() async {
     var result = await resolveTestCodeWithDiagnostics(r'''
 extension E1 on int {
   set a(x) {}
 }

 extension E2 on int {
   set a(x) {}
 }

 f() {
   0.a = 3;
 //  ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
 }
 ''');

     var node = result.findNode.assignment('= 3');
     assertResolvedNodeText(node, r'''
 AssignmentExpression
   leftHandSide: PropertyAccess
     target: IntegerLiteral
       literal: 0
       staticType: int
     operator: .
     propertyName: SimpleIdentifier
       token: a
       element: <null>
       staticType: null
     staticType: null
   operator: =
   rightHandSide: IntegerLiteral
     literal: 3
     correspondingParameter: <null>
     staticType: int
   readElement: <null>
   readType: null
   writeElement: <null>
   writeType: InvalidType
   element: <null>
   staticType: int
 ''');
   }

   test_unnamed_extensions() async {
     await resolveTestCodeWithDiagnostics(r'''
 class A {}
 class B {}
 class C extends A implements B {}

 extension on List<A> {
   int call() => 0;
 }

 extension on List<B> {
   int call() => 0;
 }

 int f(List<C> x) => x();
 //                  ^
 // [diag.ambiguousExtensionMemberAccessTwo] A member named 'call' is defined in 'extension on List<A>' and 'extension on List<B>', and neither is more specific.

 // Additional calls to avoid UNUSED_ELEMENT
 int g(List<A> x) => x();
 int h(List<B> x) => x();
 ''');
   }
 }
	// Copyright (c) 2019, 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.

	import 'package:test_reflective_loader/test_reflective_loader.dart';

	import '../dart/resolution/context_collection_resolution.dart';
	import '../dart/resolution/node_text_expectations.dart';

	main() {
	defineReflectiveSuite(() {
	defineReflectiveTests(AmbiguousExtensionMemberAccessTest);
	defineReflectiveTests(UpdateNodeTextExpectations);
	});
	}

	@reflectiveTest
	class AmbiguousExtensionMemberAccessTest extends PubPackageResolutionTest {
	test_call() async {
	await resolveTestCodeWithDiagnostics(r'''
	class A {}

	extension E1 on A {
	int call() => 0;
	}

	extension E2 on A {
	int call() => 0;
	}

	int f(A a) => a();
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'call' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
	''');
	}

	test_getter_getter() async {
	var result = await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int {
	void get a => 1;
	}

	extension E2 on int {
	void get a => 2;
	}

	f() {
	0.a;
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');

	var node = result.findNode.propertyAccess('0.a');
	assertResolvedNodeText(node, r'''
	PropertyAccess
	target: IntegerLiteral
	literal: 0
	staticType: int
	operator: .
	propertyName: SimpleIdentifier
	token: a
	element: <null>
	staticType: InvalidType
	staticType: InvalidType
	''');
	}

	test_getter_getterStatic() async {
	var result = await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int {
	void get a => 1;
	}

	extension E2 on int {
	static void get a => 2;
	}

	f() {
	0.a;
	}
	''');

	var node = result.findNode.propertyAccess('0.a');
	assertResolvedNodeText(node, r'''
	PropertyAccess
	target: IntegerLiteral
	literal: 0
	staticType: int
	operator: .
	propertyName: SimpleIdentifier
	token: a
	element: <testLibrary>::@extension::E1::@getter::a
	staticType: void
	staticType: void
	''');
	}

	test_getter_method() async {
	var result = await resolveTestCodeWithDiagnostics(r'''
	extension E on int {
	int get a => 1;
	}

	extension E2 on int {
	void a() {}
	}

	f() {
	0.a;
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E on int' and 'extension E2 on int', and neither is more specific.
	}
	''');

	var node = result.findNode.propertyAccess('0.a');
	assertResolvedNodeText(node, r'''
	PropertyAccess
	target: IntegerLiteral
	literal: 0
	staticType: int
	operator: .
	propertyName: SimpleIdentifier
	token: a
	element: <null>
	staticType: InvalidType
	staticType: InvalidType
	''');
	}

	test_getter_setter() async {
	var result = await resolveTestCodeWithDiagnostics(r'''
	extension E on int {
	int get a => 1;
	}

	extension E2 on int {
	set a(int v) { }
	}

	f() {
	0.a;
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E on int' and 'extension E2 on int', and neither is more specific.
	}
	''');

	var node = result.findNode.propertyAccess('0.a');
	assertResolvedNodeText(node, r'''
	PropertyAccess
	target: IntegerLiteral
	literal: 0
	staticType: int
	operator: .
	propertyName: SimpleIdentifier
	token: a
	element: <null>
	staticType: InvalidType
	staticType: InvalidType
	''');
	}

	test_method_conflict_conflict_notSpecific() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int { void foo() {} }
	extension E2 on int { void foo() {} }
	extension E on int? { void foo() {} }
	void f() {
	0.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');
	}

	test_method_conflict_conflict_notSpecific_sameName() async {
	var one = getFile('$testPackageLibPath/one.dart');
	var two = getFile('$testPackageLibPath/two.dart');

	await resolveFilesWithDiagnostics({
	one: '''
	extension E on int { void foo() {} }
	// ^
	// [context 1] E is defined in /home/test/lib/one.dart
	''',
	two: '''
	extension E on int { void foo() {} }
	// ^
	// [context 2] E is defined in /home/test/lib/two.dart
	''',
	testFile: '''
	// ignore_for_file: unused_import
	import 'one.dart';
	import 'two.dart';
	void f() {
	0.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessTwo][context 1][context 2] A member named 'foo' is defined in 'extension E on int (where E is defined in /home/test/lib/one.dart)' and 'extension E on int (where E is defined in /home/test/lib/two.dart)', and neither is more specific.
	}
	''',
	});
	}

	test_method_conflict_conflict_notSpecific_sameName_invalidType() async {
	await resolveTestCodeWithDiagnostics(r'''
	// ignore_for_file: unused_element
	void f(Iterable<void> p) {
	p.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessTwo][context 1][context 2] A member named 'foo' is defined in 'extension on Iterable<InvalidType> (where <unnamed extension> is defined in /home/test/lib/test.dart)' and 'extension on Iterable<InvalidType> (where <unnamed extension> is defined in /home/test/lib/test.dart)', and neither is more specific.
	}
	extension on Iterable<Undef1> { void foo() {} }
	// [context 1][column 1][length 0] <unnamed extension> is defined in /home/test/lib/test.dart
	// ^^^^^^
	// [diag.nonTypeAsTypeArgument] The name 'Undef1' isn't a type, so it can't be used as a type argument.
	extension on Iterable<Undef2> { void foo() {} }
	// [context 2][column 1][length 0] <unnamed extension> is defined in /home/test/lib/test.dart
	// ^^^^^^
	// [diag.nonTypeAsTypeArgument] The name 'Undef2' isn't a type, so it can't be used as a type argument.
	''');
	}

	test_method_conflict_conflict_specific() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int? { void foo() {} }
	extension E2 on int? { void foo() {} }
	extension E on int { void foo() {} }
	void f() {
	0.foo();
	}
	''');
	}

	test_method_conflict_notSpecific_conflict() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int { void foo() {} }
	extension E on int? { void foo() {} }
	extension E2 on int { void foo() {} }
	void f() {
	0.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');
	}

	test_method_conflict_specific_conflict() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int? { void foo() {} }
	extension E on int { void foo() {} }
	extension E2 on int? { void foo() {} }
	void f() {
	0.foo();
	}
	''');
	}

	test_method_method() async {
	var result = await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int {
	void a() {}
	}

	extension E2 on int {
	void a() {}
	}

	f() {
	0.a();
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');

	var node = result.findNode.methodInvocation('0.a()');
	assertResolvedNodeText(node, r'''
	MethodInvocation
	target: IntegerLiteral
	literal: 0
	staticType: int
	operator: .
	methodName: SimpleIdentifier
	token: a
	element: <null>
	staticType: InvalidType
	argumentList: ArgumentList
	leftParenthesis: (
	rightParenthesis: )
	staticInvokeType: InvalidType
	staticType: InvalidType
	''');
	}

	test_method_notSpecific_conflict_conflict() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E on int? { void foo() {} }
	extension E1 on int { void foo() {} }
	extension E2 on int { void foo() {} }
	void f() {
	0.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');
	}

	test_method_notSpecific_conflict_conflict_conflict() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E on int? { void foo() {} }
	extension E1 on int { void foo() {} }
	extension E2 on int { void foo() {} }
	extension E3 on int { void foo() {} }
	void f() {
	0.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessThreeOrMore] A member named 'foo' is defined in extension 'E1', extension 'E2', and extension 'E3', and none are more specific.
	}
	''');
	}

	test_method_specific_conflict_conflict() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E on int { void foo() {} }
	extension E1 on int? { void foo() {} }
	extension E2 on int? { void foo() {} }
	void f() {
	0.foo();
	}
	''');
	}

	test_method_triple_conflict_sameName() async {
	var one = getFile('$testPackageLibPath/one.dart');
	var two = getFile('$testPackageLibPath/two.dart');
	var three = getFile('$testPackageLibPath/three.dart');

	await resolveFilesWithDiagnostics({
	one: '''
	extension E on int { void foo() {} }
	// ^
	// [context 1] E is defined in /home/test/lib/one.dart
	''',
	two: '''
	extension E on int { void foo() {} }
	// ^
	// [context 2] E is defined in /home/test/lib/two.dart
	''',
	three: '''
	extension E1 on int { void foo() {} }
	''',
	testFile: '''
	// ignore_for_file: unused_import
	import 'one.dart';
	import 'two.dart';
	import 'three.dart';
	void f() {
	0.foo();
	// ^^^
	// [diag.ambiguousExtensionMemberAccessThreeOrMore][context 1][context 2] A member named 'foo' is defined in extension 'E', extension 'E', and extension 'E1', and none are more specific.
	}
	''',
	});
	}

	test_noMoreSpecificExtension() async {
	await resolveTestCodeWithDiagnostics(r'''
	class Target<T> {}

	class SubTarget<T> extends Target<T> {}

	extension E1 on SubTarget<Object> {
	int get foo => 0;
	}

	extension E2<T> on Target<T> {
	int get foo => 0;
	}

	f(SubTarget<num> t) {
	// The instantiated on type of `E1(t)` is `SubTarget<Object>`.
	// The instantiated on type of `E2(t)` is `Target<num>`.
	// Neither is a subtype of the other, so the resolution is ambiguous.
	t.foo;
	// ^^^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'foo' is defined in 'extension E1 on SubTarget<Object>' and 'extension E2<T> on Target<T>', and neither is more specific.
	}
	''');
	}

	test_operator_binary() async {
	await resolveTestCodeWithDiagnostics(r'''
	class A {}

	extension E1 on A {
	A operator +(A a) => a;
	}

	extension E2 on A {
	A operator +(A a) => a;
	}

	A f(A a) => a + a;
	// ^^^^^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named '+' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
	''');
	}

	test_operator_binary_compoundAssignment() async {
	await resolveTestCodeWithDiagnostics(r'''
	class A {}

	extension E1 on A {
	A operator +(_) => this;
	}

	extension E2 on A {
	A operator +(_) => this;
	}

	void f(A a) {
	a += 0;
	// ^^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named '+' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
	}
	''');
	}

	test_operator_index_index() async {
	await resolveTestCodeWithDiagnostics(r'''
	class A {}

	extension E1 on A {
	int operator [](int i) => 0;
	}

	extension E2 on A {
	int operator [](int i) => 0;
	}

	int f(A a) => a[0];
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named '[]' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
	''');
	}

	test_operator_index_indexEq() async {
	await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int {
	int operator[](int index) => 0;
	}

	extension E2 on int {
	void operator[]=(int index, int value) {}
	}

	f() {
	0[1] += 2;
	//^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named '[]' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');
	}

	test_operator_unary() async {
	await resolveTestCodeWithDiagnostics(r'''
	class A {}

	extension E1 on A {
	int operator -() => 0;
	}

	extension E2 on A {
	int operator -() => 0;
	}

	int f(A a) => -a;
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'unary-' is defined in 'extension E1 on A' and 'extension E2 on A', and neither is more specific.
	''');
	}

	test_setter_setter() async {
	var result = await resolveTestCodeWithDiagnostics(r'''
	extension E1 on int {
	set a(x) {}
	}

	extension E2 on int {
	set a(x) {}
	}

	f() {
	0.a = 3;
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'a' is defined in 'extension E1 on int' and 'extension E2 on int', and neither is more specific.
	}
	''');

	var node = result.findNode.assignment('= 3');
	assertResolvedNodeText(node, r'''
	AssignmentExpression
	leftHandSide: PropertyAccess
	target: IntegerLiteral
	literal: 0
	staticType: int
	operator: .
	propertyName: SimpleIdentifier
	token: a
	element: <null>
	staticType: null
	staticType: null
	operator: =
	rightHandSide: IntegerLiteral
	literal: 3
	correspondingParameter: <null>
	staticType: int
	readElement: <null>
	readType: null
	writeElement: <null>
	writeType: InvalidType
	element: <null>
	staticType: int
	''');
	}

	test_unnamed_extensions() async {
	await resolveTestCodeWithDiagnostics(r'''
	class A {}
	class B {}
	class C extends A implements B {}

	extension on List<A> {
	int call() => 0;
	}

	extension on List<B> {
	int call() => 0;
	}

	int f(List<C> x) => x();
	// ^
	// [diag.ambiguousExtensionMemberAccessTwo] A member named 'call' is defined in 'extension on List<A>' and 'extension on List<B>', and neither is more specific.

	// Additional calls to avoid UNUSED_ELEMENT
	int g(List<A> x) => x();
	int h(List<B> x) => x();
	''');
	}
	}