Constructing object/array literals eat up significant time, to improve speed, we can lift such literals out side of function, thus by creating a closure, will remove need of initialization. And instances will be kept alive as long as the function capturing them is alive.

• The literal should not be returned
• It should not be modified in the scope of the function

        //Not working as on 11/23/2020 - Should work!!!
        //Assert.AreEqual("first", Evaluate(@"
        //    obj1 = { toString: function() { throw 'first' } };
        //    obj2 = { toString: function() { throw 'second' } };
        //    obj1.concat = String.prototype.concat;
        //    try {
        //        obj1.concat(obj2);
        //    }
        //    catch (e) {
        //        e;
        //    }"));

Actual Result:
Assert.AreEqual failed. Expected:<first (System.String)>. Actual:<[object Object] (YantraJS.Core.JSError)>
Expected: first

// Deleting variables defined within an eval statement inside a global scope succeeds.
//Assert.AreEqual(true, Evaluate("abcdefg = 1; delete abcdefg"));
//Assert.AreEqual(false, Evaluate("abcdefg = 1; delete abcdefg; this.hasOwnProperty('abcdefg')"));
//Assert.AreEqual("ReferenceError", EvaluateExceptionType("x = 5; delete x; x"));

        // Deleting variables defined within an eval statement inside a function scope succeeds.
        //Assert.AreEqual(true, Evaluate("(function() { var a = 5; return eval('var b = a; delete b'); })()"));
        //Assert.AreEqual(true, Evaluate("b = 1; (function() { var a = 5; eval('var b = a'); return delete b; })()"));
        //Assert.AreEqual(1, Evaluate("b = 1; (function() { var a = 5; eval('var b = a'); delete b; })(); b;"));
        //Assert.AreEqual(1, Evaluate("b = 1; (function() { var a = 5; eval('var b = a'); delete b; return b; })()"));

Hello again
i am trying to implement "moduleBuilder" like jint

   _context.RegisterModule("test", builder =>
            {
                builder.ExportType<TestClass>()
                    .ExportFunction("testFunc", TestMethod);
            } );

And when i try to create TestClass instance

 var barfromclass = await _context
                .RunScriptAsync("import {TestClass} from \"test\"\n export default new TestClass();",
                    String.Empty) as JSObject; 
            Assert.AreEqual("bar", barfromclass["Foo"].InvokeFunction(new Arguments()));

I am get exception

YantraJS.Core.JSException: undefined is not a function 

TestClass implementation

 public class TestClass
    {
        public string Foo() => "bar";
    }

ModuleBuilder implementation

public class ModuleBuilder
{
    private readonly KeyString _moduleName;
    private readonly JSModuleContext _moduleContext;
    private readonly JSObject _exportobj;

    internal ModuleBuilder(KeyString moduleName,JSModuleContext moduleContext)
    {
        _moduleName = moduleName;
        _moduleContext = moduleContext;
        _exportobj = new JSObject();
    }

    public ModuleBuilder ExportType<T>()
    {
        string name = typeof(T).Name;
        var type = ClrType.From(typeof(T));
        _exportobj[name] = type;
        return this;
    }

    public ModuleBuilder ExportValue(in KeyString name, object value)
    {
        _exportobj[name] = value.Marshal();
        return this;
    }

    public ModuleBuilder ExportFunction(in KeyString name, JSFunctionDelegate func)
    {
        _exportobj[name] = new JSFunction(func);
        return this;
    }

    internal void Build()
    {
        _moduleContext.RegisterModule(_moduleName, _exportobj);
    }

/// in JSModuleContext

 public void RegisterModule(in KeyString name, Action<ModuleBuilder> builder)
        {
            var modulebuilder = new ModuleBuilder(name ,this);
            builder.Invoke(modulebuilder);
            modulebuilder.Build();
        }

Maybe you can help what i do wrong?

upd some intresting information

ClrType return function() { [clr-native]}

On runing this return a VoidValueTask

When i call testFunc() this is called but dont return value

var barfromclass = await _context
                .RunScriptAsync("import {testFunc} from \"test\"\n export default testFunc();",
                    String.Empty);

Assert.AreEqual("twenty", Evaluate("array['20']")); this should return twenty but returns undefined.

I was trying to figure out how to import and use the clr module within JavaScript but I am getting an null reference exception.

                var context = new JSModuleContext();
                var r = context.Eval("import clr from \"clr\"");

i want to return an int as object in my function, but i got several false results

YConstantExpression yconstant0 = new YConstantExpression(0, typeof(int));
YExpression.TypeAs(YExpression.Box(yconstant0), typeof(object)) // Fatal error. System.AccessViolationException: Attempted to read or write protected memory.
YExpression.Convert(YExpression.Box(yconstant0), typeof(object)) // Fatal error. System.AccessViolationException: Attempted to read or write protected memory.
YExpression.Convert(YExpression.Box(yconstant0), typeof(object), true) // Fatal error. System.AccessViolationException: Attempted to read or write protected memory.
YExpression.TypeAs(yconstant0, typeof(object)) // Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
YExpression.Convert(yconstant0, typeof(object)) // Unhandled exception. System.NullReferenceException: Object reference not set to an instance of an object.
YExpression.Convert(yconstant0, typeof(object), true) // got a null object
YExpression.Box(yconstant0) // Fatal error. System.AccessViolationException: Attempted to read or write protected memory.

os: win10 x64
dotnet: net6.0 x64
code:

static Func<int, object> TestFib()
{
    var ymethod = YExpression.Lambda<Func<int, object>>(
        "ymethod",
        YExpression.Condition(
            // if (n < 2)
            ynParamI0 < yconstant2,
            // return n;
            // YExpression.TypeAs(YExpression.Box(ynParamI0), typeof(object)),
            // YExpression.Convert(YExpression.Box(ynParamI0), typeof(object)),
            // YExpression.TypeAs(ynParamI0, typeof(object)),
            // YExpression.Convert(ynParamI0, typeof(object)),

            // YExpression.TypeAs(YExpression.Box(yconstant0), typeof(object)),
            // YExpression.Convert(YExpression.Box(yconstant0), typeof(object)),
            // YExpression.Convert(YExpression.Box(yconstant0), typeof(object), true),
            // YExpression.TypeAs(yconstant0, typeof(object)),
            // YExpression.Convert(yconstant0, typeof(object)),
            // YExpression.Convert(yconstant0, typeof(object), true),
            YExpression.Box(yconstant0),

            // new YConstantExpression(0, typeof(object)),

            // else return (int)method(n - 1) + (int)method(n - 2);
            YExpression.TypeAs(
                YExpression.Unbox(YExpression.Invoke(ymethodInvokeIO, ynParamI0 - yconstant1), typeof(int)) +
                    YExpression.Unbox(YExpression.Invoke(ymethodInvokeIO, ynParamI0 - yconstant2), typeof(int)),
                typeof(object)
            )
        ),
        ynParamI0
    );
    var ypackExpr = YExpression.Lambda<Func<Func<int, object>>>(
        "ypackExpr",
        YExpression.Block(
            // Func<int, object> fibC0 = null;
            new[] { ymethodInvokeIO }.AsSequence(),
            YExpression.Assign(ymethodInvokeIO, ymethod),
            ymethodInvokeIO
        )
    );
    return ypackExpr.CompileWithNestedLambdas()();
}

Test and fix Switch Case

Assert.AreEqual(@"one\r\ntwo\r\nthree", Evaluate(@"String.rawone\r\n${'two'}\r\nthree"));
StringTests.cs -> raw()

Assert.AreEqual("1,two,3", Evaluate("array.toString()"));

Evaluate("var array = [1, ,3]");
Evaluate("Array.prototype[1] = 'two'");
Evaluate("Array.prototype[20] = 'twenty'");

output should be 1,two,3 but it gives only 1,,3; as this doesn't take two - as 2

To support IFastEnumerable<out T> add EnumeratedResult with boolean implicit and remove MoveNext methods.

Hi

I have been working with YantraJS in an experimental .NET MAUI project. I have been using version 1.2.59 and have had things working well on Windows, Android and iOS.

When attempting to update to a version later than 1.2.59, my app crashes on Android and iOS but works as before on Windows.

Only a single line of code in my app was needed to be changed to use a later version which was -

jsContext["__dataContext"] = new ClrProxy(dataContext);
to
jsContext["__dataContext"] = ClrProxy.From(dataContext);

Note that this line of code is not reached before that crash occurs.

In analyzing the problem, I have found that the crash occurs from version 1.2.93 onwards, and still occurs in the latest version as of today - 1.2.106.

On Android the last debug console output shows the following before the crash -

[monodroid-assembly] open_from_bundles: failed to load assembly YantraJS.Core.dll
Loaded assembly: /data/data/com.myapp.net/files/.__override__/YantraJS.Core.dll [External]
[monodroid-assembly] open_from_bundles: failed to load assembly YantraJS.ExpressionCompiler.dll
Loaded assembly: /data/data/com.myapp.net/files/.__override__/YantraJS.ExpressionCompiler.dll [External]
[i.myapp.ne] Closures.set dateTimeFormat-:0,0: not enough values (1 < 2) on stack at 0008
[i.myapp.ne] * Assertion at /__w/1/s/src/mono/mono/mini/interp/transform.c:4488, condition `td->sp >= td->stack' not met
[libc] Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 14573 (i.myapp.net), pid 14573 (i.myapp.net)

On iOS there is less output available but what is reported is similar in nature -

2023-01-20 15:48:49.088647+1100 MobileApp[81252:2402105] warning: Closures.set dateTimeFormat-:0,0: not enough values (1 < 2) on stack at 0008
2023-01-20 15:48:49.088965+1100 MobileApp[81252:2402105] error: * Assertion at /Users/runner/work/1/s/src/mono/mono/mini/interp/transform.c:4488, condition `td->sp >= td->stack' not met

As previously mentioned, there was no change in behavior on Windows and the app is working as before.

In both cases it seems like something to do with setting the dateTimeFormat when the YantraJS module is initializing.

If the YantraJS package reference is reverted back to version 1.2.59 and the single line of code changed back to use new, everything works fine again.

//Assert.AreEqual(false, Evaluate("x.hasOwnProperty('0')")); -> This TC fails

    public static JSValue Reverse(in Arguments a) {

}

Assert.AreEqual(true, Evaluate("Array[Symbol.species] === Array"));

Hi I'm not sure if this library supports Xamarin but I tried the sample code

var context = new JSContext();

// create global function
context["add"] = new JSFunction((in Arguments a) => {
    return new JSNumber(
         (a[0]?.IntValue ?? 0) + (a[1]?.IntValue ?? 0)
    );
});

var result = context.Eval("add(4,5)", "script.js");

and got the following error

System.InvalidProgramException: 'Invalid IL code in (wrapper dynamic-method) YantraJS.Closures:body-:0,0 (YantraJS.Closures,YantraJS.Core.Arguments&): IL_00d0: pop       

The library doesn't seem to work when producing a self contained, trimmed, executable.
The code of the program is:

using YantraJS.Core;
using var ctx = new JSContext();

Console.WriteLine(ctx.Eval("'Hi'").ToString());

Running without trimming works, and prints Hi. When trimming is on, running said executable produces:

Unhandled exception. System.MissingMethodException: Cannot dynamically create an instance of type 'YantraJS.Core.JSJSON'. Reason: No parameterless constructor defined.
   at System.RuntimeType.ActivatorCache..ctor(RuntimeType)
   at System.RuntimeType.CreateInstanceOfT()
   at System.Activator.CreateInstance[T]()
   at YantraJS.Core.JSContext.<.ctor>g__CreateInternalObject|74_0[T](KeyString)
   at YantraJS.Core.JSContext..ctor(SynchronizationContext )
   at Program.<Main>$(String[]) in D:\Projects\GameEditor\GamePlayer.Desktop\Program.cs:line 2

For example,

			while (JSBoolean.True.BooleanValue)
			{
				JSVariable jSVariable12 = new JSVariable(JSUndefined.Value, "baseKey");
				JSVariable jSVariable13 = new JSVariable(JSUndefined.Value, "bp");

public void Properties()
Assert.AreEqual(true, Evaluate("new Number().constructor === Number"));

Hi there,

I've found another issue with javascript compilation. The following code, that runs ok in Chrome, won't compile:

(function foo(x) { return 0xffff & +x >>> 16; })(1234567)

Throws this exception:

YantraJS.Core.JSException
  HResult=0x80131500
  Message=Unexpected token UnsignedRightShift: >>> at 1, 39
  Source=YantraJS.Core
  StackTrace:
at Compile in Unknown:line 1

Steps to reproduce:

1. Run the following C# in net6 (Program.cs):

   using YantraJS;
   using YantraJS.Core;
   
   new JSContext();
   CoreScript.Evaluate("(function foo(x) { return 0xffff & +x >>> 16; })(1234567)");

I am trying to make some extensions and testing

When i try evaluate this code

import clr from "clr";

var Random = clr.getClass("System.Random");
var r = new Random(); // this will create instance of `System.Random`.
var n = r.next();

console.log(n)

i get exception
Object reference not set to an instance of an object

  at YantraJS.Core.FastParser.Compiler.FastCompiler.VisitImportStatement(AstImportStatement importStatement) in D:\projects\yantra\YantraJS.Core\FastParser\Compiler\FastCompiler.VisitImportStatement.cs:line 29
     at YantraJS.Utils.AstMapVisitor`1.Visit(AstNode node) in D:\projects\yantra\YantraJS.Core\FastParser\Ast\AstMapVisitor.cs:line 117
     at YantraJS.Core.FastParser.Compiler.FastCompiler.VisitProgram(AstProgram program) in D:\projects\yantra\YantraJS.Core\FastParser\Compiler\FastCompiler.VisitProgram.cs:line 58
     at YantraJS.Utils.AstMapVisitor`1.Visit(AstNode node) in D:\projects\yantra\YantraJS.Core\FastParser\Ast\AstMapVisitor.cs:line 45
     at YantraJS.Core.FastParser.Compiler.FastCompiler..ctor(StringSpan& code, String location, IList`1 argsList, ICodeCache codeCache) in D:\projects\yantra\YantraJS.Core\FastParser\Compiler\FastCompiler.cs:line 118
     at YantraJS.CoreScript.<>c__DisplayClass0_1.<Compile>b__0() in D:\projects\yantra\YantraJS.Core\CoreScript.cs:line 43
     at YantraJS.Emit.DictionaryCodeCache.<>c__DisplayClass2_0.<GetOrCreate>b__0(StringSpan k) in D:\projects\yantra\YantraJS.Core\Emit\DictionaryCodeCache.cs:line 21
     at YantraJS.Core.Core.Storage.ConcurrentStringMap`1.GetOrCreate(StringSpan& key, Func`2 value) in D:\projects\yantra\YantraJS.Core\Core\Storage\ConcurrentStringMap`1.cs:line 93
     at YantraJS.Emit.DictionaryCodeCache.GetOrCreate(JSCode& code) in D:\projects\yantra\YantraJS.Core\Emit\DictionaryCodeCache.cs:line 20
     at YantraJS.Emit.DictionaryCodeCache.YantraJS.Emit.ICodeCache.GetOrCreate(JSCode& code)
     at YantraJS.CoreScript.Compile(StringSpan& code, String location, IList`1 args, ICodeCache codeCache) in D:\projects\yantra\YantraJS.Core\CoreScript.cs:line 46
     at YantraJS.CoreScript.Evaluate(String code, String location, ICodeCache codeCache) in D:\projects\yantra\YantraJS.Core\CoreScript.cs:line 70
     at YantraJS.Core.JSContext.<>c__DisplayClass96_0.<<Eval>b__0>d.MoveNext() in D:\projects\yantra\YantraJS.Core\Core\JSContext.cs:line 693
  --- End of stack trace from previous location ---
     at Microsoft.Threading.AsyncPump.Run[T](Func`1 func) in D:\projects\yantra\YantraJS.Core\Core\Promise\AsyncPump.cs:line 32
     at YantraJS.Core.JSContext.Eval(String code, String codeFilePath) in D:\projects\yantra\YantraJS.Core\Core\JSContext.cs:line 692
     at Program.<Main>$(String[] args) in D:\projects\yantra\test\Program.cs:line 10

During debugging, it was found that the variable "require" is null
and when calling require.Expression a NullReferenceException occurs
Please Fix

Additional Info

Code for test

My patch, that i want PR (this doent break code ExpressionCompiler)

Assert.AreEqual(true, Evaluate(@"
'use strict';
var success = false;
'test'.replace('e', function (x, y) {
success = this === undefined;
});
success"));

Assert.AreEqual(true, Evaluate("parameterValues[0].hasOwnProperty(2)")); -> This TC fails

public static JSValue Shift(in Arguments a) method in JSArrayPrototype

TC: ArrayTests.cs

Evaluate("var x = [1, 2, 3]");
Evaluate("delete x[2]");
Assert.AreEqual(false, Evaluate("x.hasOwnProperty('1')"));

Hello,

I've got a tiny question (or feature request). Is there a way to enforce CSP when executing script using Yantra?

E.g. consider the following code:

CoreScript.Evaluate("new Function(\"return this\")()");

returns undefined.

I am wondering if there is a way to configure yantra to throw an exception when doing dynamic JavaScript evaluation, e.g. eval(str), new Function(str)() or string arguments for setTimeout and setInterval functions?

Many thanks.

Hello, Akash!

Most JS engines, when embedding .NET types and objects, uses a Pascal case to access its members. I know that this behavior can be changed using an JSExportSameName attribute, but this is not always convenient. It would be convenient to disable a Camel case when creating an instance of the JSContext class.

YantraJS fails to parse https://cdn.jsdelivr.net/npm/[email protected]/linq.js , most likely the RegExp parsing skips few tokens. Looks like token expression is mismatched against argArray.

Optimize (...arguments), we can pass reference to existing Arguments struct as we no longer use callee.

toFixed() - JSNumberPrototype.cs

Imported Testcase - NumberTests.cs

1. Assert.AreEqual("1234567890123456768", Evaluate("1234567890123456789 .toFixed(0)"));

2. Assert.AreEqual("77.12739999999999440661", Evaluate("77.1274.toFixed(20)"))

Similar errors in toPrecision() and toString()

This was purposely done, but we might revisit this.

//Assert.AreEqual("6,2,9", Evaluate(@"
// var x = [9, 2, 6];
// x[Symbol.iterator] = function() {
// var i = 3;
// return {
// next: function() {
// i --;
// return i < 0 ? { done: true } : { value: x[i] };
// }
// };
// };
// Int16Array.from(x).toString()"));

    //  Assert.AreEqual("-115.4621320712601014", Evaluate("(-77.598).toString(8)"));
        // Assert.AreEqual("0.00142233513615237575", Evaluate("0.003.toString(8)"));
      //  Assert.AreEqual("27524716460150203300000000000000000", Evaluate("15e30.toString(8)"));
      //  Assert.AreEqual("0.252525252525252525", Evaluate("(1/3).toString(8)"));

Also, below tcs expected result were modified:
// Assert.AreEqual("18014398509481990", Evaluate("18014398509481992 .toString()"));
// Assert.AreEqual("18014398509482010", Evaluate("18014398509482008 .toString()"));
// Assert.AreEqual("1234567890123456800", Evaluate("1234567890123456789 .toString()"));
// Assert.AreEqual("2234567890123456800", Evaluate("2234567890123456789 .toString()"));
// Assert.AreEqual("3234567890123457000", Evaluate("3234567890123456789 .toString()"));
// Assert.AreEqual("4234567890123457000", Evaluate("4234567890123456789 .toString()"));
// Assert.AreEqual("72057594037927940", Evaluate("72057594037927944 .toString()"));
// Assert.AreEqual("72057594037927950", Evaluate("72057594037927945 .toString()"));
to c# specific result

Assert.AreEqual(true, Evaluate("[][Symbol.iterator] === [].values"));

//Assert.AreEqual(true, Evaluate(@"
// var global = this;
// var success = false;
// 'test'.replace('e', function (x, y) {
// success = this === global;
// });
// success"));

TC not supported yet
// Assert.AreEqual("TypeError: The in operator expected an object, but found 'number' instead", EvaluateExceptionMessage("'toString' in 5"));

Hi,

Great work with this library. I have been evaluating it for some of my projects. Unfortunately, I am having an issue with some JS code.

Attempting to compile the following javascript code:

(function(){return 1; /***/ })()

Throws this exception:

YantraJS.Core.JSException
  HResult=0x80131500
  Message=Unexpected token EOF:  at 0, 0
  Source=YantraJS.Core
  StackTrace:
at Compile in Unknown:line 0

Steps to reproduce:

1. Run the following C# in net6 (Program.cs):

   using YantraJS;
   using YantraJS.Core;
   
   new JSContext();
   CoreScript.Evaluate("(function(){return 1; /***/ })()");

Workaround:

Obviously, I can remove the comments 😺 (e.g. using regex), but this is just one example of a code coming from Webpack that I need to execute dynamically so more permanent solution would be appreciated.

Assert.AreEqual(PropertyAttributes.Sealed, EvaluateAccessibility("Array", "prototype")); in public void Constructor()

// Check boundary conditions.
Assert.AreEqual(4294967295.0, Evaluate("new Array(4294967293).unshift(1, 2)"));

Issue is in JSOBject.cs file
internal override void MoveElements(int start, int to)

Try improving stack guard by measuring pointer distance instead of counter.

this is not available

// Deleting a global variable fails.
Assert.AreEqual(false, Evaluate("Object.getOwnPropertyDescriptor(this, 'delete_test_1').configurable"));

This doesnt work in strict mdoe

// Delete from a parent scope.
//Assert.AreEqual(false, Evaluate("a = 5; function f() { delete a } f(); this.hasOwnProperty('a')"));

https://raw.githubusercontent.com/mihaifm/linq/master/linq.js

Evaluate("var array = Object.create(['one', 'two', 'three'])");

Assert.AreEqual(3, Evaluate("array.length")); - should return 3, but gives Object reference not set to an instance of an object.

Assert.AreEqual("one", Evaluate("array[0]"));
Assert.AreEqual("one", Evaluate("array['0']"));
Assert.AreEqual("two", Evaluate("array[1]"));
Assert.AreEqual("three", Evaluate("array[2]"));

The documentation on ClrProxy was outdated but I was able to figure out how use it. The following is an example.

using YantraJS.Core;
using YantraJS.Core.Clr;

var synchronizationContext = new SynchronizationContext();
var context = new JSContext(synchronizationContext);

var calculator = new Calculator();
context["calculator"] = ClrProxy.From(calculator);

var a0 = await context.ExecuteAsync("calculator.add(1,1)");                 // a0 = {2} JSNumber
var a1 = await context.ExecuteAsync("await calculator.addAsync(1,1);");     // a1 = {2} JSNumber

public class Calculator
{
    public int Add(int x, int y)
    {
        return x + y;
    }

    public Task<int> AddAsync(int x, int y)
    {
        return Task.FromResult(x + y);
    }
}

iterator() in StringTests.cs is not implemented

// Strict mode: attempts to set a variable that has not been declared is disallowed.
// Assert.AreEqual("ReferenceError", EvaluateExceptionType("'use strict'; asddfsgwqewert = 'test'"));
// Assert.AreEqual("ReferenceError", EvaluateExceptionType("function foo() { 'use strict'; asddfsgwqewert = 'test'; } foo()"));

// In compatibility mode, undefined and null are converted to objects.
//CompatibilityMode = CompatibilityMode.ECMAScript3;
//try
//{
// Assert.AreEqual(true, Evaluate("hasOwnProperty('NaN')"));
// Assert.AreEqual(true, Evaluate("hasOwnProperty.call(null, 'NaN')"));
// Assert.AreEqual(true, Evaluate("hasOwnProperty.call(undefined, 'NaN')"));
//}
//finally
//{
// CompatibilityMode = CompatibilityMode.Latest;
//}

The following code is resulting with the error: System.ArgumentOutOfRangeException: StartIndex cannot be less than zero. (Parameter 'startIndex')

var synchronizationContext = new SynchronizationContext();
var context = new JSContext(synchronizationContext);
await context.ExecuteAsync("const sleep = ms => new Promise(r => setTimeout(r, ms));");
await context.ExecuteAsync("await sleep(1000);");

Am I doing something wrong?

Array Tests - Boundary Condition
Assert.AreEqual(4294967295.0, Evaluate("new Array(4294967293).unshift(1, 2)"));

I've summarily checked the codebase and it seems there aren't many options to sandbox the scripts. Is this in the scope of this project?
If so, it would be great to be able to do the following (in descending priority):

• limit CLR interop on a whitelist basis
• limit the number of instructions to be executed
• limit total memory allocated
• limit the recursion depth
• limit the total execution time