How to accomplish two way communication between .NET and JS?

[maticcavalleri]

I'm struggling to implement two way communication with this library. Issue might be related to #330.

I'm using .NET as my main program from which I load my JS (ES module, not CommonJS) like this:

[JSExport]
public class TestClass
{
    private NodejsEnvironment NodeJSEnvironment;
    private NodejsPlatform nodejsPlatform;

    public async Task Start()
    {
        var baseDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;
        var libnodePath = "/path/to/libnode.dll";
        nodejsPlatform = new(libnodePath);
        NodeJSEnvironment = nodejsPlatform.CreateEnvironment("/path/to/project");
        var pid = Process.GetCurrentProcess().Id;
        var inspectionUri = NodeJSEnvironment.StartInspector();
        await NodeJSEnvironment.SynchronizationContext.RunAsync(async () =>
        {
            try
            {
                var jsModule = await NodeJSEnvironment.ImportAsync("./dist/TSTest.js", esModule: true);
                var x = (int)jsModule.CallMethod("callFromDotNet");
            }
            catch (Exception e)
            {
                throw;
            }
        });
    }

    [JSExport]
    public static void CallFromJS()
    {
        Console.WriteLine("Call From JS Success");
    }
}

And my JS file looks like this:

import dotnet from 'node-api-dotnet';

const testClass = dotnet.require('TestClass');
testClass.StaticClass.CallFromJS();

function callFromDotNet() {
    return 42;
}
export { callFromDotNet };

I am using version 0.8.8 for micorosft.javascript.nodeapi and nodeapi.generator nugets. I'm using the same version for JS import.

Issue is that when importing package to JS file I get a crashing error:

Unhandled Exception: System.EntryPointNotFoundException: Arg_EntryPointNotFoundExceptionParameterizedNoLibrary, napi_create_string_utf16
   at System.Runtime.InteropServices.NativeLibrary.GetSymbol(IntPtr, String, Boolean) + 0x57
   at Microsoft.JavaScript.NodeApi.Runtime.NodejsRuntime.CreateString(JSRuntime.napi_env, ReadOnlySpan`1, JSRuntime.napi_value&) + 0x62
   at Microsoft.JavaScript.NodeApi.JSValue.CreateStringUtf16(String) + 0x72
   at Microsoft.JavaScript.NodeApi.JSValue.op_Implicit(String) + 0x15
   at Microsoft.JavaScript.NodeApi.DotNetHost.NativeHost.InitializeModule(JSRuntime.napi_env, JSRuntime.napi_value) + 0x435

I realize that in documentation it says to use import statement like import dotnet from 'node-api-dotnet/net8.0.js'; with ES module but this is also not working for me. I get error: JSException: Package subpath './net8.0.js' is not defined by "exports"

Is documentation found at https://microsoft.github.io/node-api-dotnet/ outdated?

With this code if I remove dotnet import statement and just keep the exported callFromDotNet function from .js file I am able to call JS functions from .NET (one way communication), but how can I also call .NET methods from this same .js file?

Is two way communication like this possible? What am I doing wrong?

[maticcavalleri]

I tried a different approach, I am now only using the nuget, without node-api-dotnet npm package.

From C# I am creating callable methods with:

JSValue.CreateFunction("dotNetMethod", DotNetMethod, IntPtr.Zero);

And I am passing this method to JS when I'm calling it, this is how I inject the methods:

jsModule.CallMethod("passDotNetMethods", dotNetMethods);

where dotNetMethods is an array of methods I'm creating with CreateFunction() like above.

From JS I am then able to invoke this methods and pass arguments to them, which works as intended.

This approach seems to work but I'm still somewhat confused as this is not mentioned in examples/documentation. Is this how it should be done now?