LanguageFeatures/Control-flow-collections/type_inference_A10_t03.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 set element type of e1 is S1 and the inferred set element
/// type of e2 is S2 then the inferred set element type of element is the least
/// upper bound of S1 and S2.
///
/// @description Checks that if the inferred set element type of e1 is S1 and the
/// inferred set element type of e2 is S2 then the inferred set element type of
/// element is the least upper bound of S1 and S2.
/// @author sgrekhov@unipro.ru

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

main() {
  var i = 1;
  var x = [1, 2, 3] as List<int>?;
  var y = [1.1, 2.2, 3.3] as List<double>?;
  var set1 = {
    if (i > 0) ...?x else ...?y,
  };
  Expect.isTrue(set1 is Set<num>);
  Expect.isFalse(set1 is Set<double>);
  Expect.isFalse(set1 is Set<int>);
  Expect.runtimeIsType<Set<num>>(set1);
  Expect.runtimeIsNotType<Set<int>>(set1);
  Expect.runtimeIsNotType<Set<double>>(set1);

  var set2 = {
    "",
    if (i < 0) ...?x else ...?y,
  };
  Expect.isTrue(set2 is Set<Object>);
  Expect.isFalse(set2 is Set<String>);
  Expect.isFalse(set2 is Set<num>);
  Expect.runtimeIsType<Set<Object>>(set2);
  Expect.runtimeIsNotType<Set<String>>(set2);
  Expect.runtimeIsNotType<Set<num>>(set2);
}