Calling async C# method from async JavaScript

[Soundman32]

Are there any examples on how to call an async C# method from a JS script, and what the methods should look like?

For example, given the following code (ignore _logger, that works fine):

I've enabled TaskPromiseConversion:

using var engine = new V8ScriptEngine(V8ScriptEngineFlags.EnableTaskPromiseConversion);

javascript:

(async () => {
    _logger.LogInformation("Start");
    await _http.GetAsync("https://cnn.com")
        .then((response) => {
            _logger.LogInformation("R:{response}", response);
        });
    _logger.LogInformation("End");
})();

And the C# method is declared like this:

public Task<TResponse> GetAsync<TResponse>(string url)

I can see Start in the log, but the GetAsync doesn't get called (I have a breakpoint on that line), and End isn't in the log.

[ClearScriptLib]

Hi @Soundman32,

public Task<TResponse> GetAsync<TResponse>(string url)

I can see Start in the log, but the GetAsync doesn't get called (I have a breakpoint on that line),

GetAsync requires an explicit type argument for TResponse, but your script code doesn't provide one. You need to expose the relevant host type – say, SomeResponse – and use the following syntax: _http.GetAsync(SomeResponse, 'https://cnn.com')

and End isn't in the log.

It would be helpful to know how you're invoking your script code and awaiting its completion.

Thanks!