React-native: Simulator waits for processing a request using fetch until a click is made on the screen

[alfonsoperez]

Hi all,

In one of my action callers of my app, where I need to call an external API (using fetch api), I have something like this.

console.log('fetching...');

_pendingRequests[key] = fetch(url, metadata).then(r => r.json())
                                .then(data => { dispatch(key, data, params) })
                                .catch(apiError);

With all the other fetches everything works fine, but there is a fetch that happens when some coordinates are updated, the callback is called, and thus this action caller is called,

fetching...

is displayed in the console but until I don't CLICK on the simulator the promise is not resolved and so the response is not dispatched, in the device everything works as expected.

What can it be?

Thanks

[ide]

Are you using the Chrome debugger? I could see that causing issues... Basically your click is causing React Native's event loop to run and I think another event loop (V8 maybe) is running without RN being aware of it.

[alfonsoperez]

humm.. yes, in fact when I disable Chrome debugger now it doesn't work at all (ie. the request arrives to the backend but the promise is not resolved, clicking on the screen or not)

[brentvatne]

I think we need more information about the context of this fetch call -- given that all others work fine, there is nothing specific about this that I see causing problems. Please try to post a reproducible example that we can run against! Otherwise there's not much more we can say here :smile:

[brentvatne]

Closing, ping me when you have a chance to reply and I can reopen!

[eremzeit]

I'm seeing this same behavior. It only happens when using the chrome debugger. I'm digging in and will report back when I know more.

[eremzeit]

Oh, I upgraded to 0.24.x to 0.26.x and the problem was resolved.

[duanhaowei]

I also have this problem and it happen on 0.26.x , when i use code from https://facebook.github.io/react-native/docs/sample-application-movies.html

when i disable Chrome debug "remote debug" model , the bug is gone.
so it seem like something wrong wiht remote debug

[martin-cech]

Hi, I'm having exactly the same issue in 0.33 after upgrade from 0.32. After disconnecting from the debugger it works fine

[victor-falcon]

Same problem as @martin-cech says... 😕

[martin-cech]

Turns out it might not be relevant to version of React, I reverted to 0.32 and the problem was still there. I tried deleting node_modules folder, even completely clean git checkout but nothing worked. I think after

rm -rf /usr/local/lib/node_modules/npm/node_modules

the issue went away. No guarantees whether that works or why, I was just trying to clean as much as possible.

[ewendel]

I'm seeing the same problem now, with RN 0.45.1 and React 16.0.0-alpha.12.

[giulianok]

I'm having the same issue. When I'm debugging with Chrome, for each request, I have to click on the app (simulator) to be able to make each request. Without debugging I works fine :(

[guilhermemello]

Same problem.
RN 0.46.1