Delay request/response

Hi! Would be great to have ability to delay request to backend server or response to client in onProxyReq or onProxyRes hooks respectively. I think this can be done by returning promise from this hooks (just proposal) This is needed sometimes to emulate long backend response for some concrete url, not for all of them (this can be done with devtools network throttling).

Thank you!

[chimurai]

Hi @klimashkin,

Been thinking about this feature too…

Decided not to implement this for the various reasons:

• Simulating network conditions properly is tough and is beyond the scope of this middleware.
• Adds complexity to project
• Other tools allow you to simulate network conditions; for example Chrome Dev Tools.

If you still want to delay (certain) requests, you can do it quite easily by chaining middlewares:

var exampleProxy = proxy({
    target: 'http://www.example.com',
    changeOrigin: true
});

var delay = function (req, res, next) {
    console.log('[debug] Delaying %s for %sms ', req.originalUrl, 10000);
    setTimeout(next, 10000);
};

app.use('/api', delay, exampleProxy);

[chimurai]

Awesome! Thanks for sharing the answer.

Think it would make an excellent candidate for a delay/latency recipe.

Do you mind creating a PR of the snippet and add it to the http-proxy-middleware recipes? https://github.com/chimurai/http-proxy-middleware/tree/master/recipes

All credits are yours of course.