sebastienros.jint/Jint.Tests/Runtime/InteropTests.MemberAccess.cs

using System.Collections;
using System.Diagnostics.CodeAnalysis;
using Jint.Native;
using Jint.Runtime;
using Jint.Runtime.Interop;
using Jint.Tests.Runtime.Domain;

namespace Jint.Tests.Runtime;

public partial class InteropTests
{
    [Fact]
    public void ShouldHideSpecificMembers()
    {
        var engine = new Engine(options => options.SetMemberAccessor((e, target, member) =>
        {
            if (target is HiddenMembers)
            {
                if (member == nameof(HiddenMembers.Member2) || member == nameof(HiddenMembers.Method2))
                {
                    return JsValue.Undefined;
                }
            }

            return null;
        }));

        engine.SetValue("m", new HiddenMembers());

        Assert.Equal("Member1", engine.Evaluate("m.Member1").ToString());
        Assert.Equal("undefined", engine.Evaluate("m.Member2").ToString());
        Assert.Equal("Method1", engine.Evaluate("m.Method1()").ToString());
        // check the method itself, not its invokation as it would mean invoking "undefined"
        Assert.Equal("undefined", engine.Evaluate("m.Method2").ToString());
    }

    [Fact]
    public void ShouldOverrideMembers()
    {
        var engine = new Engine(options => options.SetMemberAccessor((e, target, member) =>
        {
            if (target is HiddenMembers && member == nameof(HiddenMembers.Member1))
            {
                return "Orange";
            }

            return null;
        }));

        engine.SetValue("m", new HiddenMembers());

        Assert.Equal("Orange", engine.Evaluate("m.Member1").ToString());
    }

    [Fact]
    public void ShouldBeAbleToFilterMembers()
    {
        var engine = new Engine(options => options
            .SetTypeResolver(new TypeResolver
            {
                MemberFilter = member => !Attribute.IsDefined(member, typeof(ObsoleteAttribute))
            })
        );

        engine.SetValue("m", new HiddenMembers());

        Assert.True(engine.Evaluate("m.Field1").IsUndefined());
        Assert.True(engine.Evaluate("m.Member1").IsUndefined());
        Assert.True(engine.Evaluate("m.Method1").IsUndefined());

        Assert.True(engine.Evaluate("m.Field2").IsString());
        Assert.True(engine.Evaluate("m.Member2").IsString());
        Assert.True(engine.Evaluate("m.Method2()").IsString());

        // we forbid GetType by default
        Assert.True(engine.Evaluate("m.GetType").IsUndefined());
    }

    [Fact]
    public void ShouldBeAbleToExposeGetType()
    {
        var engine = new Engine(options =>
        {
            options.Interop.AllowGetType = true;
            options.Interop.AllowSystemReflection = true;
        });
        engine.SetValue("m", new HiddenMembers());
        Assert.True(engine.Evaluate("m.GetType").IsCallable);

        // reflection could bypass some safeguards
        Assert.Equal("Method1", engine.Evaluate("m.GetType().GetMethod('Method1').Invoke(m, [])").AsString());
    }

    [Fact]
    public void ShouldBeAbleToVaryGetTypeConfigurationBetweenEngines()
    {
        static string TestAllowGetTypeOption(bool allowGetType)
        {
            var uri = new Uri("https://github.com/sebastienros/jint");
            const string Input = nameof(uri) + ".GetType();";

            using var engine = new Engine(options => options.Interop.AllowGetType = allowGetType);
            engine.SetValue(nameof(uri), JsValue.FromObject(engine, uri));
            var result = engine.Evaluate(Input).ToString();
            return result;
        }

        Assert.Equal("System.Uri", TestAllowGetTypeOption(allowGetType: true));

        var ex = Assert.Throws<JavaScriptException>(() => TestAllowGetTypeOption(allowGetType: false));
        Assert.Equal("Property 'GetType' of object is not a function", ex.Message);
    }

    [Fact]
    public void ShouldProtectFromReflectionServiceUsage()
    {
        var engine = new Engine();
        engine.SetValue("m", new HiddenMembers());

        // we can get a type reference if it's exposed via property, bypassing GetType
        var type = engine.Evaluate("m.Type");
        Assert.IsType<ObjectWrapper>(type);

        var ex = Assert.Throws<InvalidOperationException>(() => engine.Evaluate("m.Type.Module.GetType().Module.GetType('System.DateTime')"));
        Assert.Equal("Cannot access System.Reflection namespace, check Engine's interop options", ex.Message);
    }

    [Fact]
    public void TypeReferenceShouldUseTypeResolverConfiguration()
    {
        var engine = new Engine(options =>
        {
            options.SetTypeResolver(new TypeResolver
            {
                MemberFilter = member => !Attribute.IsDefined(member, typeof(ObsoleteAttribute))
            });
        });
        engine.SetValue("EchoService", TypeReference.CreateTypeReference(engine, typeof(EchoService)));
        Assert.Equal("anyone there", engine.Evaluate("EchoService.Echo('anyone there')").AsString());
        Assert.Equal("anyone there", engine.Evaluate("EchoService.echo('anyone there')").AsString());
        Assert.True(engine.Evaluate("EchoService.ECHO").IsUndefined());

        Assert.True(engine.Evaluate("EchoService.Hidden").IsUndefined());
    }

    [Fact]
    public void CustomDictionaryPropertyAccessTests()
    {
        var engine = new Engine(options =>
        {
            options.AllowClr();
        });

        var dc = new CustomDictionary<float>();
        dc["a"] = 1;

        engine.SetValue("dc", dc);

        Assert.Equal(1, engine.Evaluate("dc.a"));
        Assert.Equal(1, engine.Evaluate("dc['a']"));
        Assert.NotEqual(JsValue.Undefined, engine.Evaluate("dc.Add"));
        Assert.NotEqual(0, engine.Evaluate("dc.Add"));
        Assert.Equal(JsValue.Undefined, engine.Evaluate("dc.b"));

        engine.Execute("dc.b = 5");
        engine.Execute("dc.Add('c', 10)");
        Assert.Equal(5, engine.Evaluate("dc.b"));
        Assert.Equal(10, engine.Evaluate("dc.c"));
    }

    [Fact]
    public void CanAccessBaseClassStaticFields()
    {
        var engine = new Engine(options =>
        {
            options.AllowClr();
        });

        engine.SetValue("B", TypeReference.CreateTypeReference(engine, typeof(InheritingFromClassWithStatics)));
        Assert.Equal(42, engine.Evaluate("B.a").AsNumber());
        Assert.Equal(24, engine.Evaluate("B.a = 24; B.a").AsNumber());
    }

    private class BaseClassWithStatics
    {
#pragma warning disable CS0414 // Field is assigned but its value is never used
        public static int a = 42;
#pragma warning restore CS0414 // Field is assigned but its value is never used
    }

    private class InheritingFromClassWithStatics : BaseClassWithStatics
    {
    }

    private static class EchoService
    {
        public static string Echo(string message) => message;

        [Obsolete]
        public static string Hidden(string message) => message;
    }

    private class CustomDictionary<TValue> : IDictionary<string, TValue>
    {
        readonly Dictionary<string, TValue> _dictionary = new Dictionary<string, TValue>();

        public TValue this[string key]
        {
            get
            {
                if (TryGetValue(key, out var val)) return val;

                // Normally, dictionary Item accessor throws an error when key does not exist
                // But this is a custom implementation
                return default;
            }
            set
            {
                _dictionary[key] = value;
            }
        }

        public ICollection<string> Keys => _dictionary.Keys;
        public ICollection<TValue> Values => _dictionary.Values;
        public int Count => _dictionary.Count;
        public bool IsReadOnly => false;
        public void Add(string key, TValue value) => _dictionary.Add(key, value);
        public void Add(KeyValuePair<string, TValue> item) => _dictionary.Add(item.Key, item.Value);
        public void Clear() => _dictionary.Clear();
        public bool Contains(KeyValuePair<string, TValue> item) => _dictionary.ContainsKey(item.Key);
        public bool ContainsKey(string key) => _dictionary.ContainsKey(key);
        public void CopyTo(KeyValuePair<string, TValue>[] array, int arrayIndex) => throw new NotImplementedException();
        public IEnumerator<KeyValuePair<string, TValue>> GetEnumerator() => _dictionary.GetEnumerator();
        public bool Remove(string key) => _dictionary.Remove(key);
        public bool Remove(KeyValuePair<string, TValue> item) => _dictionary.Remove(item.Key);
        public bool TryGetValue(string key, [MaybeNullWhen(false)] out TValue value) => _dictionary.TryGetValue(key, out value);
        IEnumerator IEnumerable.GetEnumerator() => _dictionary.GetEnumerator();
    }

    public class ClassWithData
    {
        public int Age => 42;

        public DataType Data { get; set; }

        public class DataType
        {
            public string Value { get; set; }
        }
    }

    [Fact]
    public void NewTypedObjectFromUntypedInitializerShouldBeMapped()
    {
        var engine = new Engine();

        engine.SetValue("obj", new ClassWithData());
        engine.Execute("obj.Data = { Value: '123' };");
        var obj = engine.Evaluate("obj").ToObject() as ClassWithData;

        Assert.Equal("123", obj?.Data.Value);
    }

    [Fact]
    public void CanConfigureStrictAccess()
    {
        var engine = new Engine();

        engine.SetValue("obj", new ClassWithData());
        engine.Evaluate("obj.Age").AsNumber().Should().Be(42);
        engine.Evaluate("obj.AgeMissing").Should().Be(JsValue.Undefined);

        engine = new Engine(options =>
        {
            options.Interop.ThrowOnUnresolvedMember = true;
        });

        engine.SetValue("obj", new ClassWithData());
        engine.Evaluate("obj.Age").AsNumber().Should().Be(42);

        engine.Invoking(e => e.Evaluate("obj.AgeMissing")).Should().Throw<MissingMemberException>();
    }
}