blob: e88235359383b49346bef7ccc493614d280689e2 [file] [log] [blame]
// Copyright (c) 2015, 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.
// Verify semantics of the ?. operator when it is used to invoke a method.
import "package:expect/expect.dart";
import "conditional_access_helper.dart" as h;
bad() {
Expect.fail('Should not be executed');
}
class B {}
class C extends B {
f(callback()) => callback();
int g(int callback()) => callback();
static staticF(callback()) => callback();
static int staticG(int callback()) => callback();
}
C nullC() => null;
main() {
// Make sure the "none" test fails if method invocation using "?." is not
// implemented. This makes status files easier to maintain.
nullC()?.f(null);
// o?.m(...) is equivalent to ((x) => x == null ? null : x.m(...))(o).
Expect.equals(null, nullC()?.f(bad()));
Expect.equals(1, new C()?.f(() => 1));
// C?.m(...) is equivalent to C.m(...).
Expect.equals(1, C?.staticF(() => 1));
Expect.equals(1, h.C?.staticF(() => 1));
// The static type of o?.m(...) is the same as the static type of
// o.m(...).
{ int i = nullC()?.g(bad()); Expect.equals(null, i); }
{ int i = new C()?.g(() => 1); Expect.equals(1, i); }
{ String s = nullC()?.g(bad()); Expect.equals(null, s); }
// ^^^^^^^^^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.INVALID_ASSIGNMENT
// [cfe] A value of type 'int' can't be assigned to a variable of type 'String'.
{ String s = new C()?.g(() => null); Expect.equals(null, s); }
// ^^^^^^^^^^^^^^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.INVALID_ASSIGNMENT
// ^
// [cfe] A value of type 'int' can't be assigned to a variable of type 'String'.
{ int i = C?.staticG(() => 1); Expect.equals(1, i); }
{ int i = h.C?.staticG(() => 1); Expect.equals(1, i); }
{ String s = C?.staticG(() => null); Expect.equals(null, s); }
// ^^^^^^^^^^^^^^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.INVALID_ASSIGNMENT
// ^
// [cfe] A value of type 'int' can't be assigned to a variable of type 'String'.
{ String s = h.C?.staticG(() => null); Expect.equals(null, s); }
// ^^^^^^^^^^^^^^^^^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.INVALID_ASSIGNMENT
// ^
// [cfe] A value of type 'int' can't be assigned to a variable of type 'String'.
// Let T be the static type of o and let y be a fresh variable of type T.
// Exactly the same static warnings that would be caused by y.m(...) are also
// generated in the case of o?.m(...).
{ B b = new C(); Expect.equals(1, b?.f(() => 1)); }
// ^
// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_METHOD
// [cfe] The method 'f' isn't defined for the class 'B'.
{ int i = 1; Expect.equals(null, nullC()?.f(i)); }
// ^
// [analyzer] COMPILE_TIME_ERROR.ARGUMENT_TYPE_NOT_ASSIGNABLE
// [cfe] The argument type 'int' can't be assigned to the parameter type 'dynamic Function()'.
// '?.' can't be used to access toplevel functions in libraries imported via
// prefix.
h?.topLevelFunction();
//^
// [analyzer] COMPILE_TIME_ERROR.PREFIX_IDENTIFIER_NOT_FOLLOWED_BY_DOT
// [cfe] A prefix can't be used with null-aware operators.
// Nor can it be used to access the toString method on the class Type.
Expect.throwsNoSuchMethodError(() => C?.toString());
// ^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_METHOD
// [cfe] Method not found: 'C.toString'.
Expect.throwsNoSuchMethodError(() => h.C?.toString());
// ^^^^^^^^
// [analyzer] COMPILE_TIME_ERROR.UNDEFINED_METHOD
// [cfe] Method not found: 'C.toString'.
}