Allow flutter_rust_bridge_codegen to use fvm flutter

[BriceCroix]

Hi, first of all thank you all for this awesome project.

I would like to know if it is possible to use flutter_rust_bridge_codegen utility with fvm flutter. I do not have the regular flutter command on my computer and do not wish to install it. If you do not know FVM it is an elegant solution to manage the flutter version used by each specific project, here is its main website.

As of now, the executable exits with the following error message :

+ & "flutter" "pub" "add" "rust_lib_myproject" "--path=rust_builder"
+   ~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (flutter:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

I could not find any information about fvm in the documentation of this repository but perhaps I did not look at the right place.

If this is not possible right now, I think it would be great to add something like a --use-fvm or --flutter-path /path/to/fvm/flutter option to the codegen call.

Thanks a lot for your time !

[welcome]

Hi! Thanks for opening your first issue here! 😄

[fzyzcjy]

Looks reasonable and feel free to PR (since this does not look very hard)! Alternatively I may work on it later.

We may need to determine how to know whether to use fvm or normal flutter binary. One way may be, try to see whether fvm exists (maybe execute fvm --help and see return code is zero or nonzero), and if exists use it, otherwise do not use it.

Btw, we may also handle fvm dart (instead of dart) as well.

I guess code change may be near

flutter_rust_bridge/frb_codegen/src/library/utils/dart_repository/dart_toolchain.rs

Line 36 in 17fdf93

pub(crate) fn as_run_command(&self) -> Vec<PathBuf> {

[BriceCroix]

Thanks for looking into this ! I think the best way to determine if flutter must be used from global install or from fvm is to look for a .fvmrc file in the project directory.

Alternatively before its version 3.0, fvm used to get its configuration from the .fvm/fvm_config.json project file. One may also look for this file.

I agree that supporting pure fvm dart would also be great, I will look into how fvm configures itself in that case.

[fzyzcjy]

I think the best way to determine if flutter must be used from global install or from fvm is to look for a .fvmrc file in the project directory.

Looks reasonable! Sometimes .fvm directory is from parent folder, so we may need to recursively check as well.

Alternatively before its version 3.0

Looks like we only need to support latest fvm and no worries about old versions