Build runner throws "Bad state: Asset URI is missing for abstract class JSObject" error

[trevordunn]

Checklist

• The issue can be reproduced in the auth0_flutter sample app (or N/A).
• I have looked into the Readme, Examples, and FAQ and have not found a suitable solution or answer.
• I have looked into the API documentation and have not found a suitable solution or answer.
• I have searched the issues and have not found a suitable solution or answer.
• I have searched the Auth0 Community forums and have not found a suitable solution or answer.
• I agree to the terms within the Auth0 Code of Conduct.

Description

I've run these commands on main:

cd auth0_flutter
dart run build_runner clean
dart run build_runner build --delete-conflicting-outputs

And getting this output:

13s mockito:mockBuilder on 11 inputs: 3 output, 1 no-op; spent 9s analyzing, 4s sdk, 1s resolving; test/web/auth0_flutter_web_test.dart                                
                                                                                                                                                                       
Building, full build because builders changed.                                                                                                                         
                                                                                                                                                                       
log output for mockito:mockBuilder on test/web/auth0_flutter_web_test.dart                                                                                             
E Bad state: Asset URI is missing for abstract class JSObject                                                                                                          
  #0      _MockClassInfo._typeImport (package:mockito/src/builder.dart:2524:10)                                                                                        
  #1      _MockClassInfo._addFakeClass.<anonymous closure>.<anonymous closure>.<anonymous closure> (package:mockito/src/builder.dart:1913:25)                          
  #2      _$TypeReferenceBuilder.update (package:code_builder/src/specs/type_reference.g.dart:164:33)                                                                  
  #3      new _$TypeReference (package:code_builder/src/specs/type_reference.g.dart:22:36)                                                                             
  #4      _MockClassInfo._addFakeClass.<anonymous closure>.<anonymous closure> (package:mockito/src/builder.dart:1910:13)                                              
  #5      _MockClassInfo._withTypeParameters (package:mockito/src/builder.dart:2381:24)                                                                                
  #6      _MockClassInfo._addFakeClass.<anonymous closure> (package:mockito/src/builder.dart:1904:9)                                                                   
  #7      _$ClassBuilder.update (package:code_builder/src/specs/class.g.dart:348:33)                                                                                   
  #8      new _$Class (package:code_builder/src/specs/class.g.dart:40:28)                                                                                              
  #9      _MockClassInfo._addFakeClass (package:mockito/src/builder.dart:1897:7)                                                                                       
  #10     _MockClassInfo._dummyFakedValue (package:mockito/src/builder.dart:1849:7)                                                                                    
  #11     _MockClassInfo._dummyValueImplementing (package:mockito/src/builder.dart:1873:24)                                                                            
  #12     _MockClassInfo._dummyValue (package:mockito/src/builder.dart:1767:12)                                                                                        
  #13     _MockClassInfo._dummyValueImplementing (package:mockito/src/builder.dart:1881:7)                                                                             
  #14     _MockClassInfo._dummyValue (package:mockito/src/builder.dart:1767:12)                                                                                        
  #15     _MockClassInfo._buildOverridingGetter (package:mockito/src/builder.dart:2239:24)                                                                             
  #16     _MockClassInfo.fieldOverrides.<anonymous closure> (package:mockito/src/builder.dart:1382:36)                                                                 
  #17     _$MethodBuilder.update (package:code_builder/src/specs/method.g.dart:332:33)                                                                                 
  #18     new _$Method (package:code_builder/src/specs/method.g.dart:38:29)                                                                                            
  #19     _MockClassInfo.fieldOverrides (package:mockito/src/builder.dart:1382:15)                                                                                     
  #20     _SyncStarIterator.moveNext (dart:async-patch/async_patch.dart:597:13)                                                                                        
  #21     List.addAll (dart:core-patch/growable_array.dart:328:13)                                                                                                     
  #22     ListBuilder.addAll (package:built_collection/src/list/list_builder.dart:98:14)                                                                               
  #23     _MockClassInfo._buildMockClass.<anonymous closure>.<anonymous closure> (package:mockito/src/builder.dart:1335:30)                                            
  #24     _MockClassInfo._withTypeParameters (package:mockito/src/builder.dart:2381:24)                                                                                
  #25     _MockClassInfo._buildMockClass.<anonymous closure> (package:mockito/src/builder.dart:1285:7)                                                                 
  #26     _$ClassBuilder.update (package:code_builder/src/specs/class.g.dart:348:33)                                                                                   
  #27     new _$Class (package:code_builder/src/specs/class.g.dart:40:28)                                                                                              
  #28     _MockClassInfo._buildMockClass (package:mockito/src/builder.dart:1261:12)                                                                                    
  #29     new _MockLibraryInfo (package:mockito/src/builder.dart:1202:11)                                                                                              
  #30     MockBuilder.build (package:mockito/src/builder.dart:102:29)                                                                                                  
  <asynchronous suspension>                                                                                                                                            
  #31     runBuilder.buildForInput (package:build_runner_core/src/generate/run_builder.dart:91:7)                                                                      
  <asynchronous suspension>                                                                                                                                            
  #32     Future.wait.<anonymous closure> (dart:async/future.dart:525:21)                                                                                              
  <asynchronous suspension>                                                                                                                                            
  #33     BuildLogLogger.scopeLogAsync.<anonymous closure> (package:build_runner_core/src/logging/build_log_logger.dart:58:13)                                         
  <asynchronous suspension>                                                                                                                                            
log output for build_runner                                                                                                                                            
  Deleting 3 declared outputs which already existed on disk.                                                                                                           
Log overflowed the console, switching to line-by-line logging.
  14s mockito:mockBuilder on 11 inputs: 3 output, 2 no-op; spent 9s analyzing, 4s sdk, 1s resolving; test/web/extensions/credentials_extension_test.dart
  15s mockito:mockBuilder on 11 inputs: 3 output, 8 no-op; spent 9s analyzing, 4s sdk, 2s resolving
  Running the post build.
  Writing the asset graph.
  Failed to build with build_runner in 16s; wrote 3 outputs.

Any ideas?

Reproduction

Run these commands on main:

cd auth0_flutter
dart run build_runner clean
dart run build_runner build --delete-conflicting-outputs

Additional context

Flutter 3.35.4 • channel [user-branch] • unknown source
Framework • revision d693b4b9db (10 weeks ago) • 2025-09-16 14:27:41 +0000
Engine • hash feee8ee8fb8b975dd9990f86d3bda11e6e75faf3 (revision c298091351) (2 months ago) • 2025-09-15 14:04:24.000Z
Tools • Dart 3.9.2 • DevTools 2.48.0

auth0_flutter version

1.14.0

Flutter version

3.35.4

Platform

iOS

Platform version(s)

No response

[trevordunn]

Might be related to this? dart-lang/mockito#762

[utkrishtsahu]

Hello @trevordunn ,

Thank you for reaching out and reporting this issue.
To help us investigate this further, could you please provide the following additional information:
Could you confirm if you are running this on the main branch of a clean clone of the auth0-flutter repository without any local modifications?
Have you tried running flutter clean before running the build_runner commands?
Could you please share the output of flutter doctor -v?

[trevordunn]

Hi @utkrishtsahu,

Yes I am running this on a clean main (d263204) after running flutter clean and dart run build_runner clean.

Here is my flutter doctor -v output:

trevor@Mac flutter % flutter doctor -v
[✓] Flutter (Channel stable, 3.35.1, on macOS 15.6.1 24G90 darwin-arm64, locale en-CA) [407ms]
    • Flutter version 3.35.1 on channel stable at /Users/trevor/dev/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 20f8274939 (3 months ago), 2025-08-14 10:53:09 -0700
    • Engine revision 1e9a811bf8
    • Dart version 3.9.0
    • DevTools version 2.48.0
    • Feature flags: enable-web, enable-linux-desktop, enable-macos-desktop, enable-windows-desktop,
      enable-android, enable-ios, cli-animations, enable-lldb-debugging

[!] Android toolchain - develop for Android devices (Android SDK version 35.0.0) [1,314ms]
    • Android SDK at /Users/trevor/Library/Android/sdk
    • Emulator version 36.1.9.0 (build_id 13823996) (CL:N/A)
    • Platform android-35, build-tools 35.0.0
    • ANDROID_HOME = /Users/trevor/Library/Android/sdk
    • ANDROID_SDK_ROOT = /Users/trevor/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/java
      This is the JDK bundled with the latest Android Studio installation on this machine.
      To manually set the JDK path, use: `flutter config --jdk-dir="path/to/jdk"`.
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13391695-b895.109)
    ! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses

[✓] Xcode - develop for iOS and macOS (Xcode 26.1.1) [1,084ms]
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 17B100
    • CocoaPods version 1.16.2

[✓] Chrome - develop for the web [7ms]
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2025.1) [7ms]
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 21.0.6+-13391695-b895.109)

[✓] VS Code (version 1.106.1) [6ms]
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.122.0

[✓] Connected device (3 available) [6.7s]
    • Trevor’s iPhone 12 (wireless) (mobile) • 00008101-0011254E3AB8001E • ios            • iOS 18.6.2
      22G100
    • macOS (desktop)                        • macos                     • darwin-arm64   • macOS
      15.6.1 24G90 darwin-arm64
    • Chrome (web)                           • chrome                    • web-javascript • Google
      Chrome 142.0.7444.176

[✓] Network resources [558ms]
    • All expected network resources are available.

! Doctor found issues in 1 category.

FWIW, I've also tried running this with the latest stable flutter version 3.38.3 and am still getting the same error.

[pmathew92]

Hi @trevordunn ,
thanks for sharing these details. We will check investigate this issue. Please allow us some time

[pmathew92]

Hi @trevordunn , Looks like this is due to the limitation on Mockito. I am checkin on alternate options meanwhile to get this working with actual mocks. Thanks for your patience on this

[pmathew92]

Hi @trevordunn ,
This is fixed. I was able to run the above comments without any error

I am closing this issue for now. Please feel free to reopen if this problem still exists