proxy.browser does not support sync xhr

[rajsite]

I think the behavior I am seeing is that when proxy.browser is used to proxy synchronous requests I get an error because, the proxy seems to always returns a Promise:

https://github.com/jameslnewell/xhr-mock/blob/056283d9e184551fb4df88c9c44e34c7624a45fd/packages/xhr-mock/src/proxy.browser.ts#L21

Which fails on this check sendSync:

https://github.com/jameslnewell/xhr-mock/blob/f761cde79748561ea8288a1974c5c9dec0499a41/packages/xhr-mock/src/MockXMLHttpRequest.ts#L267

[jameslnewell]

Thanks @rajsite. Yeah sorry, I don't use async=false so I haven't implemented it yet. Want to submit a PR for supporting both sync and async?

[rajsite]

Hey @jameslnewell thanks for letting me know the state of the repo!

For the project I'm experimenting with I was leaning very heavily on the proxy feature. I needed synx xhr, timeouts, aborts, responseType arraybuffer, support for arraybuffer bodies, and probably some more to proxy correctly. I wasn't able to get to a point where I can test all of those behaviors in XHRMock but from the source it seems like a few others are probably missing besides sync xhr.

I do like the url matching ability of xhrmock but for the moment I am experimenting with xhook which seems to be proxying all of the above well so far https://github.com/jpillora/xhook/

It's CoffeeScript-based, not TypeScript-based, but it could be leveraged by XHRMock to flesh out the proxy behavior.

[jameslnewell]

No worries!

Here's what should work:

• sync xhr ½ (doesn't work with the proxy but should be a simple duplication of the current code without the promises)
• timeouts ✅
• responseType and arraybuffer ½ (only supports text at this stage but could easily be PR'd to support other bodies)

Implementing a sync proxy should be as simple as getting rid of the promise e.g:

export default function(
  req: MockRequest,
  res: MockResponse
): MockResponse {
  const xhr: XMLHttpRequest = new XHRMock.RealXMLHttpRequest();

  // TODO: reject with the correct type of error
  xhr.onerror = event => {throw event};

  xhr.onloadend = () => {
    res
      .status(xhr.status)
      .reason(xhr.statusText)
      .headers(parseHeaders(xhr.getAllResponseHeaders()))
      .body(xhr.responseText);
  };

  xhr.open(req.method(), req.url().toString());

  const headers = req.headers();
  Object.keys(headers).forEach(name => {
    const value = headers[name];
    xhr.setRequestHeader(name, value);
  });

   xhr.send(req.body());

  return res;
}

Yeah that lib looks nice too.

[rajsite]

Sync XHR has long since been deprecated and my usages were cleaned up. Doesn't seem like others have asked about it so probably fine to close out for now 👍