[Bug] Variant Enum in stream

[The-Mr-L]

Describe the bug

Hi :)
now I try to adding a rust variant enum like in the example in the guide and I get this while using the generator

when doing

pub enum KitchenSink {
    Empty,
    Primitives {
        /// Dart field comment
        int32: i32,
        float64: f64,
        boolean: bool,
    },

    Buffer(ZeroCopyBuffer<Vec<u8>>),
}
pub struct Msg {
    pub id: String,
    pub test: KitchenSink,
}

pub fn message_handler(sink: StreamSink<Msg>) -> anyhow::Result<()>{Ok(())}

if this is expected please close this :)

Codegen logs with RUST_LOG=debug env variable

[2022-04-20T15:47:54Z WARN  flutter_rust_bridge_codegen::commands] command="powershell" "-noprofile" "-c" "cd \"C:\\Users\\me\\projects\\rust\\project\"; dart run build_runner build --delete-conflicting-outputs" stdout= stderr=Could not find a file named "pubspec.yaml" in "C:\Users\me\AppData\Local\Pub\Cache\hosted\pub.dartlang.org\flutter_rust_bridge-1.25.0".
    #0      new Pubspec.load (package:pub/src/pubspec.dart:288:7)
    #1      new Package.load (package:pub/src/package.dart:149:27)
    #2      SystemCache.load (package:pub/src/system_cache.dart:113:20)
    #3      Entrypoint._createPackageGraph (package:pub/src/entrypoint.dart:112:63)
    #4      Entrypoint.packageGraph (package:pub/src/entrypoint.dart:107:54)
    #5      getExecutableForCommand (package:pub/src/executable.dart:338:19)
    #6      RunCommand.run (package:dartdev/src/commands/run.dart:232:32)
    #7      CommandRunner.runCommand (package:args/command_runner.dart:209:27)
    #8      DartdevRunner.runCommand (package:dartdev/dartdev.dart:232:30)
    #9      CommandRunner.run.<anonymous closure> (package:args/command_runner.dart:119:25)
    #10     new Future.sync (dart:async/future.dart:296:31)
    #11     CommandRunner.run (package:args/command_runner.dart:119:14)
    #12     runDartdev (package:dartdev/dartdev.dart:67:29)
    #13     main (file:///C:/b/s/w/ir/cache/builder/sdk/pkg/dartdev/bin/dartdev.dart:11:9)
    #14     _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:293:32)
    #15     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)


[2022-04-20T15:47:54Z ERROR flutter_rust_bridge_codegen::commands] Failed to run build_runner for C:\Users\me\projects\rust\project:
[2022-04-20T15:47:56Z INFO  flutter_rust_bridge_codegen] Success! Now go and use it :)

and I get errors like
lib/bridge_generated.dart(99,14): error GB1B8BC88: Method not found: 'Buffer'
etc when flutter run

[fzyzcjy]

Could not find a file named "pubspec.yaml" in "C:\Users\me\AppData\Local\Pub\Cache\hosted\pub.dartlang.org\flutter_rust_bridge-1.25.0"

Sounds like you are using a wrong folder?

[The-Mr-L]

but it works when not using the variant enum??

[The-Mr-L]

can you use variant enum in StreamSink ?

[fzyzcjy]

Not sure about that. Please provide a github repo with reproducing sample.

[The-Mr-L]

but it is just like so
api.rs

pub enum KitchenSink {
    Empty,
    Primitives {
        /// Dart field comment
        int32: i32,
        float64: f64,
        boolean: bool,
    },

    Buffer(ZeroCopyBuffer<Vec<u8>>),
}
pub struct Msg {
    pub id: String,
    pub test: KitchenSink,
}

pub fn message_handler(sink: StreamSink<Msg>) -> anyhow::Result<()>{Ok(())}

[fzyzcjy]

Well I mean a whole github repo, since in #398 we found the cause is the user does not correctly run code generators instead of bugs in this lib.

[The-Mr-L]

not correct what we found out was I used a wrong version + I later found out in the main project that I had a main.rs for testing in the native lib which for some reason conflicts when using custom data types in the StreamSink so it wont compile but worked fine otherwise.. but nvm

[huang12zheng]

I tried it and it worked @LambdaMan2K

lazy_static! { 
    pub static ref EVENT_STREAM: Option<StreamSink<String>> = Default::default(); // rust to dart event channel
}

pub fn message_handler(sink: StreamSink<Msg>){
    let _ = EVENT_STREAM;
}

@freezed
class KitchenSink with _$KitchenSink {
  const factory KitchenSink.empty() = Empty;
  const factory KitchenSink.primitives({
    /// Dart field comment
    required int int32,
    required double float64,
    required bool boolean,
  }) = Primitives;
  const factory KitchenSink.buffer(
    Uint8List field0,
  ) = Buffer;
}

class Msg {
  final String id;
  final KitchenSink test;

  Msg({
    required this.id,
    required this.test,
  });
}
Stream<Msg> messageHandler({dynamic hint}) => executeStream(FlutterRustBridgeTask(
        callFfi: (port_) => inner.wire_message_handler(port_),
        parseSuccessData: _wire2api_msg,
        constMeta: kMessageHandlerConstMeta,
        argValues: [],
        hint: hint,
      ));

[The-Mr-L]

hi, thanks for your response. I just tested it again and got the same error but I found a solution it turned out that I had to add the dev dependency build_runner to the flutter project and then the code_gen seams to finish as expected :). and in the meantime I have tested this lib with prost "protobuf" and using zerocopy for the bytes. and that seams to be working great the reason for this is I get data in this format from the api I use. so it is convenient. do you know what the overhead of serializing using this approach performance compared to your ffi well I guess you are doing ser/de at some point as well right?

[The-Mr-L]

okay I was too quick to say it worked :s then the generated dart code relays on

import 'dart:convert';
import 'dart:typed_data';
import 'package:freezed_annotation/freezed_annotation.dart';  // Not Found 

import 'dart:convert';
import 'dart:typed_data';
import 'package:flutter_rust_bridge/flutter_rust_bridge.dart'; 
import 'dart:ffi' as ffi;

part 'bridge_generated.freezed.dart';// Not Found 

[The-Mr-L]

adding freezed package solved this it seams.

[The-Mr-L]

well thanks again for sharing. I think it works now but will have to test it some more later, if it is not strange to you I have to include these dependencies then please close this. this might tho be helpful for others if they encounter the same.

[Roms1383]

Actually I ran into the very same error.

In case it helps somebody, the way I fixed it roughly is :

• follow steps on freezed install package, especially installing the dependencies

  flutter pub add freezed_annotation
  flutter pub add --dev build_runner
  flutter pub add --dev freezed

• update my Rust code, e.g. :

   use std::sync::{Mutex};
   use flutter_rust_bridge::{frb, StreamSink};
  
   #[derive(Debug, Clone)]
   #[frb(freezed)]
   pub enum API {
     Variant(Option<f64>),
     AnotherVariant(Option<f64>),
   }
  
   lazy_static::lazy_static! {
     static ref CHANNEL: Mutex<Option<StreamSink<API>>> = Mutex::new(None);
   }
  
   pub fn get_event_stream(sink: StreamSink<API>) -> anyhow::Result<()> {
       {
           let mut c = CHANNEL.lock().unwrap();
           *c = Some(sink);
       }
       Ok(())
   }
  
   pub fn dispose() -> anyhow::Result<()> {
       {
           let mut c = CHANNEL.lock().unwrap();
           if c.is_some() {
               *c = None;
           }
       }
       Ok(())
   }

• regenerate flutter rust bridge definitions

  just gen

• regenerate freezed definitions

  flutter pub run build_runner build

---

what still befuddles me is that at times I got this redundant error when using flutter rust bridge codegen but eventually the plugin would just work fine when launching. I'm very new to Flutter / Dart so please take it with a grain of salt.

click to see the error

export REPO_DIR="$PWD"; cd /; flutter_rust_bridge_codegen --rust-input "$REPO_DIR/native/src/api.rs" --dart-output "$REPO_DIR/lib/bridge_generated.dart" --c-output "$REPO_DIR/ios/Runner/bridge_generated.h" --c-output "$REPO_DIR/macos/Runner/bridge_generated.h"
[2022-07-27T12:55:33Z WARN  lib_flutter_rust_bridge_codegen::source_graph] Skipping unresolvable module bridge_generated (tried /Users/romain/Development/lab/cerclo-app/native/src/bridge_generated.rs)
[2022-07-27T12:55:34Z INFO  lib_flutter_rust_bridge_codegen] Picked config: Opts { rust_input_path: "/Users/romain/Development/lab/cerclo-app/native/src/api.rs", dart_output_path: "/Users/romain/Development/lab/cerclo-app/lib/bridge_generated.dart", dart_decl_output_path: None, c_output_path: ["/Users/romain/Development/lab/cerclo-app/ios/Runner/bridge_generated.h", "/Users/romain/Development/lab/cerclo-app/macos/Runner/bridge_generated.h"], rust_crate_dir: "/Users/romain/Development/lab/cerclo-app/native", rust_output_path: "/Users/romain/Development/lab/cerclo-app/native/src/bridge_generated.rs", class_name: "Native", dart_format_line_length: 80, skip_add_mod_to_lib: false, llvm_path: ["/opt/homebrew/opt/llvm", "/usr/local/opt/llvm", "/usr/lib/llvm-9", "/usr/lib/llvm-10", "/usr/lib/llvm-11", "/usr/lib/llvm-12", "/usr/lib/llvm-13", "/usr/lib/llvm-14", "/usr/lib/", "/usr/lib64/", "C:/Program Files/llvm", "C:/Program Files/LLVM", "C:/msys64/mingw64"], llvm_compiler_opts: "", manifest_path: "/Users/romain/Development/lab/cerclo-app/native/Cargo.toml", dart_root: Some("/Users/romain/Development/lab/cerclo-app"), build_runner: true, block_index: BlockIndex(0) }
[2022-07-27T12:55:34Z INFO  lib_flutter_rust_bridge_codegen] Phase: Parse source code to AST, then to IR
[2022-07-27T12:55:34Z WARN  lib_flutter_rust_bridge_codegen::source_graph] Skipping unresolvable module bridge_generated (tried /Users/romain/Development/lab/cerclo-app/native/src/bridge_generated.rs)
[2022-07-27T12:55:34Z INFO  lib_flutter_rust_bridge_codegen] Phase: Transform IR
[2022-07-27T12:55:34Z INFO  lib_flutter_rust_bridge_codegen] Phase: Generate Rust code
[2022-07-27T12:55:34Z INFO  lib_flutter_rust_bridge_codegen] Phase: Generate Dart code
[2022-07-27T12:55:34Z INFO  lib_flutter_rust_bridge_codegen] Phase: Other things
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::Platform - opaque (Enum is not marked with a valid #[repr(prim)] or #[repr(C)].).
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::API - opaque (Enum is not marked with a valid #[repr(prim)] or #[repr(C)].).
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::Geolocation - opaque (Struct is not marked #[repr(C)] or #[repr(transparent)].).
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::wire_platform.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::wire_rust_release_mode.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::wire_get_event_stream.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::wire_update_known_location.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::wire_dispose.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::wire_Geolocation.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::new_box_autoadd_geolocation_0.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::free_WireSyncReturnStruct.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::DartPort.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::DartPostCObjectFnType.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::store_dart_post_cobject.
[2022-07-27T12:55:34Z INFO  cbindgen::bindgen::parser] Take native::WireSyncReturnStruct.
[2022-07-27T12:55:35Z INFO  lib_flutter_rust_bridge_codegen::commands] Running build_runner at /Users/romain/Development/lab/cerclo-app
[2022-07-27T12:55:35Z WARN  lib_flutter_rust_bridge_codegen::commands] command="sh" "-c" "cd \"/Users/romain/Development/lab/cerclo-app\" && dart run build_runner build --delete-conflicting-outputs" stdout= stderr=Could not find a file named "pubspec.yaml" in "/Users/romain/.pub-cache/hosted/pub.dartlang.org/_fe_analyzer_shared-43.0.0".
    #0      new Pubspec.load (package:pub/src/pubspec.dart:307:7)
    #1      new Package.load (package:pub/src/package.dart:128:29)
    #2      SystemCache.load (package:pub/src/system_cache.dart:105:20)
    #3      Entrypoint._createPackageGraph (package:pub/src/entrypoint.dart:119:63)
    #4      Entrypoint.packageGraph (package:pub/src/entrypoint.dart:114:54)
    #5      getExecutableForCommand (package:pub/src/executable.dart:338:19)
    #6      RunCommand.run (package:dartdev/src/commands/run.dart:250:32)
    #7      CommandRunner.runCommand (package:args/command_runner.dart:209:27)
    #8      DartdevRunner.runCommand (package:dartdev/dartdev.dart:231:30)
    #9      CommandRunner.run.<anonymous closure> (package:args/command_runner.dart:119:25)
    #10     new Future.sync (dart:async/future.dart:301:31)
    #11     CommandRunner.run (package:args/command_runner.dart:119:14)
    #12     runDartdev (package:dartdev/dartdev.dart:66:29)
    #13     main (file:///opt/s/w/ir/x/w/sdk/pkg/dartdev/bin/dartdev.dart:11:9)
    #14     _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:293:32)
    #15     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)
    
    
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Failed to run build_runner for /Users/romain/Development/lab/cerclo-app: ', /Users/romain/.cargo/registry/src/github.com-1ecc6299db9ec823/flutter_rust_bridge_codegen-1.38.1/src/main.rs:24:43
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
error: Recipe `gen` failed on line 8 with exit code 101

I tried adding _fe_analyzer_shared to the dependencies, but the error remains

[Roms1383]

I'd be interested if you know what's going on @fzyzcjy.
As far as I understand, flutter rust bridge codegen thinks a dart/flutter dependency is missing, but I don't really understand the details in this context.

[fzyzcjy]

[2022-07-27T12:55:35Z WARN lib_flutter_rust_bridge_codegen::commands] command="sh" "-c" "cd "/Users/romain/Development/lab/cerclo-app" && dart run build_runner build --delete-conflicting-outputs" stdout= stderr=Could not find a file named "pubspec.yaml" in "/Users/romain/.pub-cache/hosted/pub.dartlang.org/_fe_analyzer_shared-43.0.0".

That sounds like a problem with flutter/dart.

Have you run flutter pub get?

Maybe you need to ask in Flutter/Dart community

[Roms1383]

Yeah, I've literally ran flutter pub get, also cleaned / repaired both flutter cache and dart cache (both flutter clean, flutter pub cache clean + rm -rf ~/.pub-cache, and flutter pub cache repair for example), reactivated ffigen (dart pub global activate ffigen) and the like.
After many attempts I can see it's related to the dependencies found in ~/.pub-cache/hosted/pub.dartlang.org. But whenever I add for example _fe_analyzer_shared (let's say dart pub global activate _fe_analyzer_shared 43.0.0), then another dependency is missing, and so on. That's definitely related to ffigen but I don't know yet how to fix it.

[fzyzcjy]

What about looking at the folder to see what is happening. You may need something like inotify to see what files are added/deleted during execution.

[Roms1383]

Well tbh I have no idea what to look for.
As far as I can tell when running flutter_rust_bridge_codegen it's looking for all these related dependencies and, as the error states, it's looking on my machine in ~/.pub-cache/hosted/pub.dartlang.org. Now I wonder why these aren't pulled in when activating ffigen.

[Roms1383]

Ok the error gets raised whenever the code generator calls dart run build_runner build ... because if I run it directly in the shell it outputs the very same error.

click to see error details

Could not find a file named "pubspec.yaml" in "/Users/romain/.pub-cache/hosted/pub.dartlang.org/_fe_analyzer_shared-43.0.0".
#0 new Pubspec.load (package:pub/src/pubspec.dart:307:7)
#1 new Package.load (package:pub/src/package.dart:128:29)
#2 SystemCache.load (package:pub/src/system_cache.dart:105:20)
#3 Entrypoint._createPackageGraph (package:pub/src/entrypoint.dart:119:63)
#4 Entrypoint.packageGraph (package:pub/src/entrypoint.dart:114:54)
#5 getExecutableForCommand (package:pub/src/executable.dart:338:19)
#6 RunCommand.run (package:dartdev/src/commands/run.dart:250:32)
#7 CommandRunner.runCommand (package:args/command_runner.dart:209:27)
#8 DartdevRunner.runCommand (package:dartdev/dartdev.dart:231:30)
#9 CommandRunner.run. (package:args/command_runner.dart:119:25)
#10 new Future.sync (dart:async/future.dart:301:31)
#11 CommandRunner.run (package:args/command_runner.dart:119:14)
#12 runDartdev (package:dartdev/dartdev.dart:66:29)
#13 main (file:///opt/s/w/ir/x/w/sdk/pkg/dartdev/bin/dartdev.dart:11:9)
#14 _delayEntrypointInvocation. (dart:isolate-patch/isolate_patch.dart:293:32)
#15 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)

Where my knowledge of Dart/Flutter ecosystem falls short is that running flutter pub run build_runner build works perfectly fine. This definitely makes me confused.

[Roms1383]

If I remove complex struct/tuple values from the enum, then the error completely disappear.
It looks like dart run build_runner build is ran whenever there are some complex values inside an enum.
Why not use flutter pub run build_runner build instead ? (maybe conditionally one or the other, if the project is pure Dart ?)

[fzyzcjy]

Good observation! You are right, for Flutter projects we should run flutter ... not dart ....

Feel free to PR!

[Roms1383]

I've made a few experiments with nested enums and here's what I found out.
In my code I have KilometerPoint and Speed, and want to send update to Flutter through a StreamSink<API>.
A working sample is like this (simplified for example) :

lazy_static::lazy_static! {
  static ref CHANNEL: Mutex<Option<StreamSink<API>>> = Mutex::new(None);
}

#[derive(Debug, Clone)]
pub enum KP {
    NoKP,
    SNCF(f64),
}

#[derive(Debug, Clone)]
pub enum Speed {
    NoSpeed,
    GPS(f64),
}

#[derive(Debug, Clone)]
#[frb(freezed)]
pub enum API {
    KilometerPointChanged(Box<KP>),
    SpeedChanged(Box<Speed>),
}

What I noticed is that :

it won't work if two or more enums have any variant named the same

lazy_static::lazy_static! {
  static ref CHANNEL: Mutex<Option<StreamSink<API>>> = Mutex::new(None);
}

#[derive(Debug, Clone)]
pub enum KP {
    Unknown, // <--- this leads to error in bridge_generated.dart
    SNCF(f64),
}

#[derive(Debug, Clone)]
pub enum Speed {
    Unknown, // <--- this leads to error in bridge_generated.dart
    GPS(f64),
}

#[derive(Debug, Clone)]
#[frb(freezed)]
pub enum API {
    KilometerPointChanged(Box<KP>),
    SpeedChanged(Box<Speed>),
}

it won't work if an enum is the named the same as another enum's variant

lazy_static::lazy_static! {
  static ref CHANNEL: Mutex<Option<StreamSink<API>>> = Mutex::new(None);
}

#[derive(Debug, Clone)]
pub enum KilometerPoint { // <--- this leads to error in bridge_generated.dart
    NoKP,
    SNCF(f64),
}

#[derive(Debug, Clone)]
pub enum Speed {
    NoSpeed,
    GPS(f64),
}

#[derive(Debug, Clone)]
#[frb(freezed)]
pub enum API {
    KilometerPoint(Box<KP>), // <--- this leads to error in bridge_generated.dart
    Speed(Box<Speed>),
}

If expressly asked, I'll set up a reproductible repo later on but just wanted to share first.

[fzyzcjy]

I see. So it looks like some kind of name conflicts. Feel free to PR!

[Roms1383]

I'm currently examining the diff between working and conflicting samples, I'm gonna open a PR as soon as I get a better idea on how to address it.

[fzyzcjy]

Sure, take your time!

[github-actions]

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