Fetch failures on Android

[ambarc]

Please provide all the information requested. Issues that do not follow this format are likely to stall.

Description

Fetch POST and PUT requests, to https endpoints, fail with "Network request failed", on android simulator. We're observing this after upgrading from 0.59.10 to 0.61.5. We can't upgrade further (yet) given other dependencies breaking.

Observation: Adding a Header object to these requests, as opposed to empty, or JS' empty object {}, leads to different behavior. All these requests work as-is on iOS. See simplified code samples.

React Native version: 0.61.5

Steps To Reproduce

Provide a detailed list of steps that reproduce the issue.

// works on 0.59.10. doesn't work on 0.61.5
fetch('target-url', {
    method: 'POST'
    headers: { h1: 'val1' } // fails where it used to succeed. Network Request Failed.
})

let h =  new Headers()
h.set('h1', 'val1')
fetch('target-url', {
    method: 'POST'
    headers: h // strangely succeeds.
})

Expected Results

Expect prior requests from 0.59.10, as described above, to work across iOS and Android.

Snack, code example, screenshot, or link to a repository:

See above.

[therealansh]

Are you using a localhost api? If so try changing the target url to http://10.0.2.2 for android emulator and if you are trying it on a real device try changing the endpoints to your computer's local IP address. But it is strange that it used to work before v0.61.5

[ambarc]

Ty! No, this is for a hosted API, not on local, using https.

[github-actions]

⚠️	Using Old Version
ℹ️	It looks like you are using an older version of React Native. Please upgrade to the latest version, and verify if the issue persists. If it does not, please let us know so we can close out this issue. This helps us ensure we are looking at issues that still exist in the current release.

[safaiyeh]

Hi @ambarc thanks for the issue! Is it similar to this? #29608

[ambarc]

It's very similar, but I think that issue might be running into broader problems. I'm trying to keep this issue open and focused on the presence of Headers being the difference between pass / fail on Android.

[safaiyeh]

Hi @ambarc looks like the issue I linked is closed and the author provided a bunch of details to resolve it. Could you give that a shot?

[brian-nicholls]

Are you using a localhost api? If so try changing the target url to http://10.0.2.2 for android emulator and if you are trying it on a real device try changing the endpoints to your computer's local IP address. But it is strange that it used to work before v0.61.5

A similar solution worked for me. My local Rails API was running on 127.0.0.1:4001. I'm using Expo, which was running my app on 10.0.0.5:19000 (my Mac's local IP). I changed my API URL when starting the rails server using rails s -b 10.0.0.5 to match Expo.

It now works on my Android emulator and device.

[vTrip]

Hey @ambarc, leaving a comment to say thank you for sharing this, after many long hours and testing of different RN versions to try and narrow my problem, this has solved it for me.

My research has found that my issue showed up with the upgrade of android SDK versions specified in the android/gradle file. Going from 28 -> 29.

Modifying my HTTP service to create the headers via new Headers() as opposed to plain JS headers = {} which previously worked with no issues for outgoing POST requests solved it for me.

I am really curious to know if this is purely a type error and why RN / fetch API throws an error for this so strictly.

Anyway, thanks for sharing, very grateful.

[SohaibKtb]

+1

[flyskywhy]

fixed TypeError: Network request failed when upload file to http not https with Android debug builds

[github-actions]

This issue is waiting for author's feedback since 24 days. Please provide the requested feedback or this will be closed in 7 days.

[github-actions]

This issue was closed because the author hasn't provided the requested feedback after 7 days.