Fetch API not working with Proguard - proguard

Question

The fetch API does not work when proguard is turned on. Below is the code snippet
try {
const response = await fetch(url, {
method: 'GET',
headers: {
'Content-Type': "application/json",
'Accept': 'application/json'
}
});
} catch (err) {
console.log(err)
}
I am able to trace the debugger till the fetch call. But after that there is neither error nor response. No errors/warnings in console as well. Any help on how to debug/solve this is much appreciated.
Im using RN v0.55.4 (latest)

Answer 1

Added the below proguard rule to fix this
-optimizations !method/*/*,!code/*/*

Answer 2

When Proguard is enabled (which it is by default for Android release builds), it can rename the BuildConfig Java class in the minification process and prevent Fetch from referencing it.
To avoid this, add an exception to android/app/proguard-rules.pro:
-keep class com.mypackage.BuildConfig { *; }
This package name should be same as your app's package name.
Also do add the Progurad rules of Okhttp3 and Okio as well.
The final proguard might look like this for a React Native project
-keep public class com.horcrux.svg.** {*;}
-keep class com.facebook.react.turbomodule.** { *; }
-dontwarn okio.**
-keep class com.swiggyvendorapp.BuildConfig { *; }
-dontwarn com.squareup.okhttp.**
-keep class com.squareup.okhttp.** { *; }
-keep interface com.squareup.okhttp.** { *; }
-dontwarn retrofit.**
-dontwarn retrofit.appengine.UrlFetchClient
-keep class retrofit.** { *; }
-keepclasseswithmembers class * {
#retrofit.http.* <methods>;
}
-keepattributes Signature
-keepattributes *Annotation*

Answer 3

The fetch() method takes one mandatory argument, the path to the resource you want to fetch. It returns a Promise that resolves to the Response to that request, whether it is successful or not.
you need to modify like below
fetch(url)
.then((resp) => resp.json()) // Transform the data into json
.then(function(data) {
// your code logic with the response
})
})