pkg/compiler/test/codegen/simple_inferrer_relations_test.dart

// Copyright (c) 2013, 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.

// @dart = 2.7

/// TODO(johnniwinther): Port this test to use the equivalence framework.

import 'package:async_helper/async_helper.dart';
import 'package:expect/expect.dart';

import '../helpers/compiler_helper.dart';

// Test that if (x == y) where we know nothing about x and y will get optimized
// to if ($.$eq(x, y)) and not
// to if ($.$eq(x, y) == true)
// This is an optimization based on seeing that all the relational operators,
// ==, <, >, <=, >= only have implementations that return bool.

const String TEST = """
int inscrutable(int x) => x == 0 ? 0 : x | inscrutable(x & (x - 1));

class A {
  A(this.foo);
  int foo;
  operator==(other) {
    // Make the source size and AST size bigger so that it is not analyzed
    // first.
    1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+1+11+1+1+1+11+1+1+11+1+1;
    return this.foo == other.foo;
  }
}

class B extends A {
  B(int foo, this.bar) : super(foo);
  int bar;
  operator==(other) {
    if (other.bar != bar) return false;
    return other.foo == foo;
  }
}

main() {
  var a = new A(inscrutable(0) == 0 ? 42 : "fish");
  var b = new B(0, inscrutable(0) == 0 ? 2 : "horse");
  var c = inscrutable(0) == 0 ? a : "kurt";
  var d = inscrutable(0) == 0 ? b : "gert";
  if (c == d) {
    print("hestfisk");
  }
}
""";

void main() {
  runTest() async {
    String generated = await compileAll(TEST);
    if (generated.contains(r'=== true')) {
      print(generated);
      Expect.fail("missing elision of '=== true'");
    }
  }

  asyncTest(() async {
    print('--test from kernel------------------------------------------------');
    await runTest();
  });
}