sebastienros.jint/Jint.Tests/Runtime/StringTests.cs

namespace Jint.Tests.Runtime;

public class StringTests
{
    public StringTests()
    {
        _engine = new Engine()
            .SetValue("log", new Action<object>(Console.WriteLine))
            .SetValue("assert", new Action<bool>(Assert.True))
            .SetValue("equal", new Action<object, object>(Assert.Equal));
    }

    private readonly Engine _engine;

    [Fact]
    public void StringConcatenationAndReferences()
    {
        const string script = @"
var foo = 'foo';
foo += 'foo';
var bar = foo;
bar += 'bar';
";
        var value = _engine.Execute(script);
        var foo = _engine.Evaluate("foo").AsString();
        var bar = _engine.Evaluate("bar").AsString();
        Assert.Equal("foofoo", foo);
        Assert.Equal("foofoobar", bar);
    }

    [Fact]
    public void TrimLeftRightShouldBeSameAsTrimStartEnd()
    {
        _engine.Execute(@"
                assert(''.trimLeft === ''.trimStart);
                assert(''.trimRight === ''.trimEnd);
");
    }

    [Fact]
    public void HasProperIteratorPrototypeChain()
    {
        const string Script = @"
        // Iterator instance
        var iterator = ''[Symbol.iterator]();
        // %StringIteratorPrototype%
        var proto1 = Object.getPrototypeOf(iterator);
        // %IteratorPrototype%
        var proto2 = Object.getPrototypeOf(proto1);";

        var engine = new Engine();
        engine.Execute(Script);
        Assert.True(engine.Evaluate("proto2.hasOwnProperty(Symbol.iterator)").AsBoolean());
        Assert.True(engine.Evaluate("!proto1.hasOwnProperty(Symbol.iterator)").AsBoolean());
        Assert.True(engine.Evaluate("!iterator.hasOwnProperty(Symbol.iterator)").AsBoolean());
        Assert.True(engine.Evaluate("iterator[Symbol.iterator]() === iterator").AsBoolean());
    }
}