fetch() works on simulator but not on device: TypeError: Failed to fetch

[snorre.hukkelaa]

Hi,

The following function runs fine on the simulator, but when using the developer bridge and a real device I get "Something went wrong: TypeError: Failed to fetch". Hoping this would be resolved by release 3.13, but so far no luck unfortunately. Any ideas? 

function storeSet(set) {
  //ToDo remove unnessecary code after csrf token balooba
  console.log("Storing set: " + JSON.stringify(set));
  fetch(sets_url, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(set)
  })
  .then(()=>console.log("Set stored!"))
  .catch((err) => {
    console.log("Something went wrong: " + err);
  });
}

package.json:

{
  "name": "******",
  "version": "0.1.0",
  "private": true,
  "license": "UNLICENSED",
  "devDependencies": {
    "@fitbit/sdk": "~4.1.0",
    "@fitbit/sdk-cli": "^1.7.1"
  },
  "fitbit": {
    "appUUID": "***",
    "appType": "app",
    "appDisplayName": "***",
    "iconFile": "resources/icon.png",
    "wipeColor": "#ffffff",
    "requestedPermissions": [
      "access_internet",
      "run_background"
    ],
    "buildTargets": [
      "higgs",
      "meson",
      "gemini",
      "mira"
    ],
    "i18n": {},
    "defaultLanguage": "en-US"
  },
  "scripts": {
    "build": "fitbit-build",
    "debug": "fitbit"
  }
}

[Gondwana]

http or https?

[snorre.hukkelaa]

Same problem with both 

[Gondwana]

access_internet permission?

[snorre.hukkelaa]

Yes I've added the permission but same problem. 

[JonFitbit]

What's `sets_url`? Mask anything sensitive.

[snorre.hukkelaa]

http://127.0.0.1:8000/sets/

[JonFitbit]

Is it possible there's an issue with your server implementation? You can verify the Fitbit app companion code is working by running kWS and testing a fetch().

https://play.google.com/store/apps/details?id=org.xeustechnologies.android.kws&hl=en

[snorre.hukkelaa]

Seems to be the same issue no matter what url I use. Even though I'm running my server in debug mode I cannot see any sight that a request is being received. 

[JonFitbit]

Which version of Android are you using?

[snorre.hukkelaa]

I`m on a Huawei P30 running Android 10

[JonFitbit]

And you're definitely using the 3.13 Fitbit app?

How did you get on with kWS?

[snorre.hukkelaa]

Yes positive :

Same thing with kws, no sign of any request being received. Do you have any tips on how to debug this programmatically? Where is the error message "Failed to fetch" thrown from? Sounds pretty generic 

[Sergius]

Chech your device webview version: it might need to support fetch https://caniuse.com/#feat=fetch

@JonFitbit does fitbit app polyfill the fetch function?

If not, there may be Android devices stuck with chrome 38 that has no fetch.

[snorre.hukkelaa]

Well, I installed the latest version of Android System Webview but same problem. I think I will try a different phone and see if things change 

[TechFan7]

Any update on this issue?  Did you get it working?  I am trying to send requests (fetch) to a local home automation server in the 10.x.x.x range.  Not working with HTTPS (self-signed) or HTTP.  Dev API documentation says it should work if by IP to local computers.

[snorre.hukkelaa]

@TechFan7 No unfortunately I've not gotten it to work. Tried two different phones after the last update, Huawei P3 and an iPhone 6S but still got the same error. So I've basically given up for now. What phone and app version are you using? 

[TechFan7]

I was just about to start developing for an internal system. . .and have run into this.  I have Pixel 3a and with Android 10.  It appears I have version 3.18.