[Firestore] INTERNAL ASSERTION FAILED: Encoded field value should not be null.

Environment

• Android Studio version: 3.2 RC3
• Firebase Component: Firestore
• Component version: 17.1.1

Problem

Occasionally, when creating a new object, I get this:

    java.lang.RuntimeException: Internal error in Firestore (0.6.6-dev).
        at com.google.firebase.firestore.obfuscated.zzgf.zzb(com.google.firebase:firebase-firestore@@17.1.1:377)
        at com.google.firebase.firestore.obfuscated.zzgk.run(Unknown Source:2)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
     Caused by: java.lang.AssertionError: INTERNAL ASSERTION FAILED: Encoded field value should not be null.
        at com.google.firebase.firestore.obfuscated.zzge.zza(com.google.firebase:firebase-firestore@@17.1.1:3046)
        at com.google.firebase.firestore.obfuscated.zzge.zza(com.google.firebase:firebase-firestore@@17.1.1:3031)
        at com.google.firebase.firestore.obfuscated.zzfu.zza(com.google.firebase:firebase-firestore@@17.1.1:262)
        at com.google.firebase.firestore.obfuscated.zzfu.zza(com.google.firebase:firebase-firestore@@17.1.1:957)
        at com.google.firebase.firestore.obfuscated.zzfu.zzb(com.google.firebase:firebase-firestore@@17.1.1:727)
        at com.google.firebase.firestore.obfuscated.zzbf.zza(com.google.firebase:firebase-firestore@@17.1.1:166)
        at com.google.firebase.firestore.obfuscated.zzcy.zzc(com.google.firebase:firebase-firestore@@17.1.1:103)
        at com.google.firebase.firestore.obfuscated.zzcy.zza(com.google.firebase:firebase-firestore@@17.1.1:142)
        at com.google.firebase.firestore.obfuscated.zzbg.zza(com.google.firebase:firebase-firestore@@17.1.1:524)
        at com.google.firebase.firestore.obfuscated.zzbo.run(Unknown Source:6)
        at com.google.firebase.firestore.obfuscated.zzcw.zza(com.google.firebase:firebase-firestore@@17.1.1:150)
        at com.google.firebase.firestore.obfuscated.zzbg.zza(com.google.firebase:firebase-firestore@@17.1.1:514)
        at com.google.firebase.firestore.obfuscated.zzak.zza(com.google.firebase:firebase-firestore@@17.1.1:173)
        at com.google.firebase.firestore.obfuscated.zzk.zza(com.google.firebase:firebase-firestore@@17.1.1:91)
        at com.google.firebase.firestore.obfuscated.zzm.zzb(com.google.firebase:firebase-firestore@@17.1.1:137)
        at com.google.firebase.firestore.obfuscated.zzw.run(Unknown Source:4)
        at com.google.firebase.firestore.obfuscated.zzgf.zzc(com.google.firebase:firebase-firestore@@17.1.1:309)
        at com.google.firebase.firestore.obfuscated.zzgj.call(Unknown Source:2)
        at com.google.firebase.firestore.obfuscated.zzgf.zza(com.google.firebase:firebase-firestore@@17.1.1:285)
        at com.google.firebase.firestore.obfuscated.zzgi.run(Unknown Source:4)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:457)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:301)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
        at com.google.firebase.firestore.obfuscated.zzgf$zza.run(com.google.firebase:firebase-firestore@@17.1.1:203)

Due to the codebase it is very hard for me to create a small reproducible sample. What I am doing is creating a new document, while I have a real time query listener. The document is created, so I assume the app crashes when the query listener is notified about it.

I will investigate more, but I could be more helpful if the owners could point me to the right direction. What is this Encoded field value? What could be the issue?

[rsgowman]

Firestore encodes/serializes data when either sending it over the network to the backend servers, or when sending it to the local disk. The field values themselves are usually just the document contents, as set by (eg) DocumentReference.set().

So, naively, this could be a Document with data that has somehow become corrupt and failing to serialize before being sent out to the network/disk.

But looking at the stack trace (which, unfortunately, is obfuscated), I can see that this is actually occurring while attempting to encode/serialize the query itself to the local disk. In particular, it looks to be the query’s ‘endAt/endBefore’ field that is causing the exception.

So take a look through your code, and see if you call endAt or endBefore anywhere. If so, take a look at the parameter(s) to those functions and see what the values are. My suspicion, is that the parameters to these functions are somehow being encoded improperly… but I’m not immediately able to come up with something that would cause this. If you can come up with a minimal repro of this problem, I can investigate further.

If you do figure out what’s causing the problem, please let us know! Even if you’re somehow passing invalid data, we should be able to catch that earlier and issue a better error message than this.

[rsgowman]

FWIW, https://github.com/firebase/firebase-android-sdk/pull/138 “fixes” this such that an exception is thrown much earlier, and is more descriptive of the problem. I’ll close this issue for now; feel free to re-open if there’s something additional you feel should happen here.