Add tests for new mixin declaration syntax.

The tests are not exhaustive, but they can hopefully be a good start when implementing the feature.

The test are not *checked* since there is currently no implementation of the feature, or even the syntax.
They should be expected to contain some errors.

Bug: dart-lang/language#7
Change-Id: I4a5364566aeba9de036e56ae188205337575154c
Reviewed-on: https://dart-review.googlesource.com/70509
Commit-Queue: Lasse R.H. Nielsen <[email protected]>
Reviewed-by: Leaf Petersen <[email protected]>

Author: lrhn

tests/language_2/language_2.status

@@ -13,21 +13,25 @@ deferred_inheritance_constraints_test/redirecting_constructor: Crash
 
 [ $compiler == dart2analyzer ]
 double_literals/*: Skip # https://github.com/dart-lang/sdk/issues/34360
+mixin_declaration/*: Skip  # See https://github.com/dart-lang/language/issues/7
 
 [ $compiler != dart2analyzer ]
 switch_case_warn_test: Skip # Analyzer only, see language_analyzer2.status
 
 [ $compiler == dart2js ]
 double_literals/*: Skip # https://github.com/dart-lang/sdk/issues/34356
 invalid_returns/*: Skip # https://github.com/dart-lang/sdk/issues/34011
+mixin_declaration/*: Skip  # See https://github.com/dart-lang/language/issues/7
 void/*: Skip # https://github.com/dart-lang/sdk/issues/34011
 
 [ $compiler == fasta ]
 double_literals/*: Skip # https://github.com/dart-lang/sdk/issues/34357
+mixin_declaration/*: Skip  # See https://github.com/dart-lang/language/issues/7
 
 [ $compiler == spec_parser ]
 double_literals/*: Skip # https://github.com/dart-lang/sdk/issues/34355
 invalid_returns/*: Skip # https://github.com/dart-lang/sdk/issues/34015
+mixin_declaration/*: Skip  # See https://github.com/dart-lang/language/issues/7
 void/*: Skip # https://github.com/dart-lang/sdk/issues/34015
 
 [ $mode == debug ]
@@ -222,6 +226,7 @@ type_parameter_test/05: Pass
 
 [ $compiler == app_jit || $compiler == app_jitk || $compiler == dartk || $compiler == dartkb || $compiler == dartkp || $compiler == none || $compiler == precompiler ]
 double_literals/*: Skip # https://github.com/dart-lang/sdk/issues/34358
+mixin_declaration/*: Skip  # See https://github.com/dart-lang/language/issues/7
 
 [ $compiler == app_jit || $compiler == none ]
 invalid_returns/*: Skip # https://github.com/dart-lang/sdk/issues/34013
@@ -230,6 +235,7 @@ void/*: Skip # https://github.com/dart-lang/sdk/issues/34013
 
 [ $compiler == dartdevc || $compiler == dartdevk ]
 double_literals/*: Skip # https://github.com/dart-lang/sdk/issues/34359
+mixin_declaration/*: Skip  # See https://github.com/dart-lang/language/issues/7
 
 [ $hot_reload || $hot_reload_rollback ]
 cha_deopt1_test: Crash # Requires deferred libraries

tests/language_2/mixin_declaration/mixin_declaration_invalid_application_supertype_test.dart

@@ -0,0 +1,33 @@
+// Copyright (c) 2018, 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:expect/expect.dart";
+
+// Test various invalid mixin applications where the supertype doesn't
+// implement the super-interfaces.
+
+abstract class UnaryNum {
+  num foo(num x) => x;
+}
+
+abstract class UnaryInt {
+  num foo(int x) => x;
+}
+
+mixin M1 on UnaryNum {}
+
+class _ = Object with M1; //# 01: compile-time error
+class _ = Null with M1; //# 02: compile-time error
+class _ = UnaryInt with M1;  //# 03: compile-time error.
+
+mixin M2 on UnaryNum, UnaryInt {}
+
+class _ = UnaryInt with M2;  //# 04: compile-time error.
+class _ = UnaryNum with M2;  //# 05: compile-time error.
+
+main() {
+  // M1 and M2 are valid types.
+  Expect.isNotType<M1>(null);
+  Expect.isNotType<M2>(null);
+}

tests/language_2/mixin_declaration/mixin_declaration_invalid_override_test.dart

@@ -0,0 +1,64 @@
+// Copyright (c) 2018, 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:expect/expect.dart";
+
+// Test various invalid super-constraints for mixin declarations.
+
+abstract class UnaryNum {
+  num foo(num x);
+}
+
+// Overides must still be valid, wrt. signatures and types.
+
+mixin M3 on UnaryNum {
+  // M3.foo is a valid override of UnaryNum.foo
+  num foo(num x) => super.foo(x) * 2;
+}
+
+// Invalid signature override (overriding optional parameter with required).
+class C3 implements UnaryNum {
+  // C3.foo is a valid override of UnaryNum.foo
+  num foo([num x]) => x ?? 17;
+}
+// M3.foo is not a valid override for C3.foo.
+class A3 extends C3 //
+    with M3 //# 06: compile-time error
+{}
+
+// Invalid type override (overriding `int` return with `num` return).
+class C4 implements UnaryNum {
+  // C4.foo is a valid override of UnaryNum.foo
+  int foo(num x) => x.toInt();
+}
+// M3.foo is not a valid override for C4.foo.
+class A4 extends C4 //
+    with M3 //# 07: compile-time error
+{}
+
+// It's not required to have an implementation of members which are not super-
+// invoked, if the application class is abstract.
+abstract class C5 {
+  num foo(num x);
+  num bar(num x);
+}
+mixin M5 on C5 {
+  num baz(num x) => super.foo(x);
+}
+abstract class C5Foo implements C5 {
+  num foo(num x) => x;
+}
+abstract class C5Bar implements C5 {
+  num bar(num x) => x;
+}
+
+// Valid abstract class, super-invocation of foo hits implementation,
+// even if bar is still abstract.
+abstract class A5Foo = C5Foo with M5;
+// Invalid since super-invocaton of foo does not hit concrete implementation.
+abstract class _ = C5Bar with M5;  //# 08: compile-time error
+
+main() {
+  Expect.equals(42, A5Foo().baz(42));
+}

tests/language_2/mixin_declaration/mixin_declaration_invalid_superinvocation_test.dart

@@ -0,0 +1,61 @@
+// Copyright (c) 2018, 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.
+
+// Test various invalid super-invocations for mixin declarations.
+
+abstract class UnaryInt {
+  num foo(int x);
+}
+
+abstract class UnaryNum {
+  num foo(num x);
+}
+
+abstract class UnaryOptionalNum {
+  num foo([num x]);
+}
+
+// Mixins may contain super-invocations.
+// The super-invocation must be valid against the combined super-interfaces
+// (i.e., valid against the most specific of them for that method).
+
+mixin M1 on UnaryNum {
+  void bar() {
+    super.foo(); //# 01: compile-time error
+    super.foo(1, 2); //# 02: compile-time error
+    super.foo("not num"); //# 03: compile-time error
+    super.bar; //# 04: compile-time error
+    super + 2; //# 05: compile-time error
+  }
+}
+
+mixin M2 on UnaryNum, UnaryInt {
+  void bar() {
+    super.foo(4.2); // Allows most specific type.
+    super.foo(1, 2); //# 06: compile-time error
+    super.foo("not num"); //# 07: compile-time error
+  }
+}
+
+mixin M3 on UnaryNum, UnaryOptionalNum {
+  void bar() {
+    super.foo(4.2);
+    super.foo();
+    super.foo(1, 2); //# 08: compile-time error
+    super.foo("not num"); //# 09: compile-time error
+  }
+}
+
+class C1 implements UnaryNum, UnaryInt, UnaryOptionalNum {
+  num foo([num x]) => x ?? 37.0;
+}
+
+class A1 = C1 with M1;
+class A2 = C1 with M2;
+class A3 = C1 with M3;
+main() {
+  A1().bar();
+  A2().bar();
+  A3().bar();
+}

tests/language_2/mixin_declaration/mixin_declaration_invalid_syntax_test.dart

@@ -0,0 +1,64 @@
+// Copyright (c) 2018, 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:expect/expect.dart";
+
+// Test various invalid syntax combinations.
+
+// You cannot prefix "mixin" with anything.
+abstract //# 01: compile-time error
+static //# 02: compile-time error
+const //# 03: compile-time error
+mixin M0 {}
+
+// Cannot use "extends".
+mixin M1 //
+  extends A //# 04: compile-time error
+{}
+
+// On-clause must be before implements clause.
+mixin M2
+  implements B //# 05: compile-time error
+  on A
+{}
+
+// Cannot use "on" on class declarations.
+class C0 //
+  on A //# 06: compile-time error
+{}
+
+// Type parameters must not be empty.
+mixin M3 //
+  <> //# 07: compile-time error
+{}
+
+// Super-class restrictions and implements must be well-formed.
+mixin M4 on List
+  <UndeclaredType> //# 08: compile-time error
+{}
+mixin M5 implements List
+  <UndeclaredType> //# 09: compile-time error
+{}
+
+mixin M6 {
+  // Mixins cannot have constructors (or members with same name as mixin).
+  factory M6() {} //# 10: compile-time error
+  M6() {} //# 11: compile-time error
+  M6.foo(); //# 12: compile-time error
+  get M6 => 42; //# 13: compile-time error
+}
+
+// Cannot declare local mixins.
+class C {
+  static mixin M {}; //# 14: compile-time error
+  mixin M {} //# 15: compile-time error
+}
+
+// Just to have some types.
+class A {}
+class B {}
+
+main() {
+  new C();
+}

tests/language_2/mixin_declaration/mixin_declaration_invalid_type_test.dart

@@ -0,0 +1,49 @@
+// Copyright (c) 2018, 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:expect/expect.dart";
+
+// Test various invalid type-declaration combinations.
+
+// Types must be class types.
+mixin M on void {} //# 01: compile-time error.
+mixin M on double {} //# 02: compile-time error.
+mixin M on FutureOr<int> {} //# 03: compile-time error.
+mixin M on FunType {} //# 04: compile-time error.
+
+mixin M implements void {} //# 05: compile-time error.
+mixin M implements double {} //# 06: compile-time error.
+mixin M implements FutureOr<int> {} //# 07: compile-time error.
+mixin M implements FunType {} //# 08: compile-time error.
+
+// Types must be extensible.
+mixin M on bool {} //# 09: compile-time error.
+mixin M on num {} //# 10: compile-time error.
+mixin M on int {} //# 11: compile-time error.
+mixin M on double {} //# 12: compile-time error.
+mixin M on Null {} //# 13: compile-time error.
+mixin M on String {} //# 14: compile-time error.
+mixin M implements bool {} //# 15: compile-time error.
+mixin M implements num {} //# 16: compile-time error.
+mixin M implements int {} //# 17: compile-time error.
+mixin M implements double {} //# 18: compile-time error.
+mixin M implements Null {} //# 19: compile-time error.
+mixin M implements String {} //# 20: compile-time error.
+
+// Mixin type cannot depend on itself
+mixin M on M {} //# 21: compile-time error.
+mixin M implements M {} //# 22: compile-time error
+
+// Types must exist and be valid
+mixin M on Undeclared {} //# 23: compile-time error
+mixin M on A<int> {} //# 24: compile-time error
+mixin M implements Undeclared {} //# 25: compile-time error
+mixin M implements A<int> {} //# 26: compile-time error
+
+main() {}
+
+// Just to have some types.
+class A {}
+class B {}
+typedef FuntType = int Function(int);

tests/language_2/mixin_declaration/mixin_declaration_invalid_usage_test.dart

@@ -0,0 +1,19 @@
+// Copyright (c) 2018, 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.
+
+mixin Mixin // cannot `extend` anything.
+  extends M //# 01: compile-time error
+  extends Object //# 02: compile-time error
+{}
+
+// You cannot extend a mixin.
+class Class // cannot extend a mixin
+  extends Mixin //# 03: compile-time error
+{}
+
+void main() {
+  // Cannot instantiate a mixin.
+  new Mixin();  //# 04: compile-time error
+  new Class();
+}

tests/language_2/mixin_declaration/mixin_declaration_nsm_test.dart

@@ -0,0 +1,39 @@
+// Copyright (c) 2018, 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:expect/expect.dart";
+
+abstract class Bar {
+  String bar();
+}
+
+abstract class Foo {
+  String foo();
+}
+
+mixin M implements Bar {
+  dynamic noSuchMethod(i) => "M${i.memberName == #foo ? "foo" : "bar"}";
+}
+
+abstract class C {
+  dynamic noSuchMethod(i) => "C${i.memberName == #foo ? "foo" : "bar"}";
+}
+
+abstract class D {
+  String foo() => "D:foo";
+  String bar() => "D:bar";
+}
+
+class A1 extends Foo with M {}
+class A2 extends C with M implements Foo {}
+class A3 extends D with M implements Foo {}
+
+main() {
+  Expect.equals("M:foo", A1().foo());
+  Expect.equals("M:bar", A1().bar());
+  Expect.equals("M:foo", A2().foo());
+  Expect.equals("M:bar", A2().bar());
+  Expect.equals("D:foo", A3().foo());
+  Expect.equals("D:bar", A3().bar());
+}