LanguageFeatures/Control-flow-collections/type_inference_A11_t02.dart

// 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.

/// @assertion If element is an ifElement with one element, p1, and no "else"
/// element:
/// ...
/// If the inferred key type of e1 is K1 and the inferred key type of e1 is V1
/// and the inferred key type of e2 is K2 and the inferred key type of e2 is V2
/// then the inferred key type of element is the least upper bound of K1 and K2
/// and the inferred value type is the least upper bound of V1 and V2.
///
/// @description Checks that if the inferred key type of e1 is K1 and the
/// inferred key type of e1 is V1 and the inferred key type of e2 is K2 and the
/// inferred key type of e2 is V2 then the inferred key type of element is the
/// least upper bound of K1 and K2 and the inferred value type is the least upper
/// bound of V1 and V2.
/// @author sgrekhov@unipro.ru

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

main() {
  var i = 1;
  var x = {1:1, 2:1, 3:3} as Map<int, int>?;
  var y = {1.1: 1.3, 2.2: 2.2, 3.3: 3.3} as Map<double, double>?;
  var map1 = {
    if (i > 0) ...?x else ...?y,
  };
  Expect.isTrue(map1 is Map<num, num>);
  Expect.isFalse(map1 is Map<int, num>);
  Expect.isFalse(map1 is Map<double, num>);
  Expect.isFalse(map1 is Map<num, int>);
  Expect.isFalse(map1 is Map<num, double>);

  var map2 = {
    "": 1,
    if (i < 0) ...?x else ...?y,
  };
  Expect.isTrue(map2 is Map<Object, num>);
  Expect.isFalse(map2 is Map<Object, int>);
  Expect.isFalse(map2 is Map<Object, double>);
  Expect.isFalse(map2 is Map<String, Object>);
  Expect.isFalse(map2 is Map<num, Object>);
}