LanguageFeatures/Records/record_expressions_A02_t03.dart

// Copyright (c) 2022, 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.

/// @assertion A record is created using a record expression. The grammar is:
///
/// literal      ::= record
///                | // Existing literal productions...
/// record       ::= 'const'? '(' recordField ( ',' recordField )* ','? ')'
/// recordField  ::= (identifier ':' )? expression
///
/// This is identical to the grammar for a function call argument list. There
/// are a couple of syntactic restrictions not captured by the grammar. It is a
/// compile-time error if a record has any of:
///
/// The same field name more than once.
///
/// Only one positional field and no trailing comma.
///
/// No fields and a trailing comma. The expression (,) isn't allowed.
///
/// A field named hashCode, runtimeType, noSuchMethod, or toString.
///
/// A field name that starts with an underscore.
///
/// A field name that collides with the synthesized getter name of a positional
/// field. For example: ('pos', $1: 'named') since the named field '$1' collides
/// with the getter for the first positional field.
///
/// @description Checks that it is no error if a record has trailing commas
/// @author sgrekhov22@gmail.com

import "../../Utils/expect.dart";

Record foo1() => (1, 2,);

Record foo2() => ((2), (3),);

Record foo3() => ((3, n: 4,), n2: "", true,);

dynamic bar(Record r) => r;

main() {
  var r1 = (1, n: "n",);
  var r2 = ((2), 3,);
  var r3 = ((3,), n: (), (4),);

  Expect.equals(1, r1.$1);
  Expect.equals("n", r1.n);
  Expect.equals(2, r2.$1);
  Expect.equals(3, r2.$2);
  Expect.equals(3, r3.$1.$1);
  Expect.equals(4, r3.$2);
  Expect.equals((), r3.n);

  Expect.equals((1, 2), foo1());
  Expect.equals((2, 3), foo2());
  Expect.equals(((3, n: 4), n2: "", true), foo3());
  Expect.equals(("Hello", 1), bar(("Hello", 1,)));
  Expect.equals((n1: "n1", n2: "n2"), bar((n1: "n1", n2: "n2",)));
}