Should we commit built_value generated code to git?

Question

built_value generates .g.dart code, but the docs don't give any hints if we should add them to our git repository or not.

I think we should, so devs cloning our repo could be up and running, without having to regenerate the code...But some people say generated code should never be committed, so, what's the recommendation for built_value?

Answer 1

If you are building a library package that you want to reuse by other packages and applications, then you should commit it.

Code generation can not generate code in dependencies and pub publish ignores .gitignored files. You would publish invalid packages. Also git-dependencies would not work in such cases.

There are packages that generate code only in the application project, also for code imported from dependencies, like reflectable does. In this case you wouldn't need to commit the generated code.

I always commit such generated code even in application projects. These files have specific extentions like .g.dart that can be excluded from code review to not cause noise or similar.

Answer 2

TLDR: if you add generated files to your git commits, and then hit any problems all you need to do is run build_runner with the flag --delete-conflicting-outputs

flutter packages pub run build_runner build --delete-conflicting-outputs

Problems of adding generated files to Git commits And how to deal with them

the mentioned build_runner documentation point on not adding generated files to your git commits is not a good point. which later i say why.

the point of adding generated files is not to be have to run build_runner each time you do a pull request and not have to deal with not adding them to git commits.

but what happens if you decide to add generated code to your git commits? and how can you easily solve them.

first problem is you might confront a merge conflict in a generated file. now how do you deal with this. you dont't. at this point you just resolve conflicts in the source file (if any) and then run build_runner and the gnerated files will be generated again.

the other problem is what mentioned in builder_runner docs. which is when you run build_runner and it gives you this error

C:\workspace\flutter\projects> flutter pub run build_runner build
[INFO] Generating build script...
[INFO] Generating build script completed, took 336ms

[WARNING] Deleted previous snapshot due to missing asset graph.
[INFO] Creating build script snapshot......
[INFO] Creating build script snapshot... completed, took 12.5s

[INFO] Initializing inputs
[INFO] Building new asset graph...
[INFO] Building new asset graph completed, took 787ms

[INFO] Checking for unexpected pre-existing outputs....
[INFO] Found 13 declared outputs which already exist on disk. This is likely because the`.dart_tool/build` folder was deleted, or you are submitting generated files to your source repository.
[SEVERE] Conflicting outputs were detected and the build is unable to prompt for permission to remove them. These outputs must be removed manually or the build can be run with `--delete-conflicting-outputs`. The outputs are: lib/models/advisory-service-item.g.dart

which you can easily solve buy adding --delete-conflicting-outputs flag when running build_runner. like we do many times already

flutter packages pub run build_runner build --delete-conflicting-outputs