Add task to install git pre-commit-hook about ktlint-gradle

[Tapchicoma]

Initial implementation was merged (should be in next 7.3.0 release). Missing:

• buildSrc support
• composite builds support

[Tapchicoma]

That are good questions 👍

Regarding them I am thinking of adding two possible git hooks:

• runs Gradle task ktlintCheck before commit
• runs Gradle task ktlintFormat before commit

This way git hook will be not detached from plugin and plugin configuration.

[Tapchicoma]

@ubuntudroid It is one of possible issues that I may work for next release.

[Tapchicoma]

Plugin can provide tasks for both check and format hooks, as implementation should be pretty similar. Then it will be up to user of plugin what to select.

[AdamMc331]

@Rubyj I have a sample project where I install the githook every time you run clean: https://github.com/AdamMc331/PokeDex/blob/master/build.gradle.kts#L54-L57

This is an easy way for new developers who clone your project to get the git hooks. I'm not sure if something like that should be added to the ktlint-gradle plugin (we might not want to make it that opinionated, plus give people a chance to write their own git hook scripts), but it should be quick to implement yourself. :)

The idea came from here: https://proandroiddev.com/ooga-chaka-git-hooks-to-enforce-code-quality-11ce8d0d23cb check the "Gradle as a trojan horse" section.

[Rubyj]

@AdamMc331 @Tapchicoma Thank you!! This should work for my use case

[JLLeitschuh]

Sounds like a sold plan. How are inputs handled? Eg. custom rulesets?

Also, once installed, this would be somewhat out-of-band from our plugin. Are we okay with that?

There are other solutions that exist for installing commit hooks with Gradle.
https://plugins.gradle.org/search?term=git-hook

[ubuntudroid]

@Tapchicoma any news here? Would be great to have that to make set up as easy as it is for ktlint.

[JLLeitschuh]

@Tapchicoma This would make sense to add as a standalone plugin, similar to ktlint-idea.

[Tapchicoma]

@JLLeitschuh not sure if this will be possible if this git hook will call ktlintCheck or ktlintFormat tasks from main plugin.

[JLLeitschuh]

If you call ktlint --install-git-pre-commit-hook what does it do?
I thought that was all this proposed addition would do, (although I'm not 100% certain that it would work in a Gradle environment).

If you're planning on having this Gradle task get executed, I think that might be outside the scope of this plugin.

I think that this goal better achieved with a plugin specific for installing pre-commit hooks.

https://plugins.gradle.org/search?term=git-hook

If you want to add a sample that demonstrates using one of these plugins, that would be an acceptable addition to this repo.

[ubuntudroid]

ktlint --install-git-pre-coomit-hook simply creates a file called pre-commit in .git/hooks which contains the code to run the checks.

This hook uses ktlint directly so we would need our own variant of the command as one of the benefits from this gradle plugin is that users don't have to have raw ktlint installed on their machine.

Having a task named installGitPreCommitHook which installs a hook executing the ktlintCheck for the user would certainly be super useful.

[JLLeitschuh]

@ubuntudroid I'm just concerned about feature creep. This seems like it's outside the scope of this project when there are other plugins that fill this niche in the ecosystem.

[ubuntudroid]

Hm, as this project provides a Gradle wrapper around ktlint and as there is such a functionality in ktlint which currently isn't supported/broken when using the Gradle plugin I personally would consider it in scope.

But surely it's up to you to decide in the end as the project lead. :)

[PaulWoitaschek]

Did someone manage to get a hook working that displays in Android Studio? On 3.5-canary7 it just shows Commit failed with error but I can't see the error at all and have to run it from the command line.

[ubuntudroid]

@PaulWoitaschek no, unfortunately not. That being said it is possible to see the error in the error event popping up after a failed commit, but the error is somewhere in that very long event message and thus super hard to find.

So right now I am doing the same and just run the ktlint gradle task manually on command line after I see that a commit has failed.

[PaulWoitaschek]

By passing the quiet flag to gradle the output is short enough that the tooltip shows information on what happened:
./gradlew ktLintCheck -q

It's not pretty and you can't just click on the lines but at least you can see something.
What I actually want is to run the formatter as well:

if ! ./gradlew ktLintCheck -q; then;
  ./gradlew ktLintFormat -q
  ./gradlew ktLintCheck -q
fi

This kind of works and formats the file correctly if possible, but the fixed formatting is not in the commit you just made.
I'm not sure if this can be solved with the plugin hooks at all.

[ubuntudroid]

I found the same. Adding `git add .` to the end of your hook kinda fixes the problem, but it will obviously also stage *all* files including those you purposely omitted during your commit. So I don't think there is any other way than letting the commit fail. The only thing to debate is whether you should run `ktlintFormat` already in your hook thus already preparing the fixes for your next stab at the commit or whether you leave that as an exercise for yourself after you got informed that your commit failed due to formatting issues. I usually do the latter for that tad bit more control, but it is a matter of taste.

…

On Tue, Mar 19, 2019, 3:49 PM Paul Woitaschek ***@***.***> wrote: By passing the quiet flag to gradle the output is short enough that the tooltip shows information on what happened: ./gradlew ktLintCheck -q It's not pretty and you can't just click on the lines but at least you can see something. What I actually want is to run the formatter as well: if ! ./gradlew ktLintCheck -q; then; ./gradlew ktLintFormat -q ./gradlew ktLintCheck -qfi This kind of works and formats the file correctly if possible, but the fixed formatting is not in the commit you just made. I'm not sure if this can be solved with the plugin hooks at all. — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#101 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAfuu5OKQxOnDY4c08ro1VY3rnRlcNwsks5vYPkWgaJpZM4Uf_Mk> .

[ljfantin]

@Tapchicoma any news here?

[Tapchicoma]

@ljfantin sorry, was busy with other tasks. I have an idea how to do it, will try to implement it this weekend.

[rubengees]

Just tried this out and the tasks do not show up in my project. Is that because the .git folder is not on the same level as the gradle project? If yes, is it possible to make that work?

My stucture looks like this:

- .git
- backend
--- build.gradle
--- src
- frontend
--- package.json

[Tapchicoma]

@rubengees yes, you are right - git hook tasks are added only if plugin was applied to the root project and there is .git folder.

I don't think that it is worth the effort to support such case - then, imho, too much corner cases plugin should handle.

To solve your particular problem - you can add "fake" .git folder - backend/.git, run install git hook task, copy the hook from backend/.git/hooks/pre-commit to .git/hooks/pre-commit and update paths in pre-commit to use backend folder.

[rubengees]

I see thanks! Will try that later. An important thing for me though is to share the setup with team members. It should be as simple as possible to get more adoption and less CI failures caused by code style issues 😁. A similar tool we use for our JavaScript frontend achieves this, by simply running one command.

[AdamMc331]

@Tapchicoma I tried this by just running .git init inside the sub folder, resyncing gradle with the idea plugin applied, but still don't see the git tasks. I do see the ktlintApplyToIdea ones though. Any other thoughts?

@rubengees Did you get a chance to try? Did it work out for you?

[Tapchicoma]

@AdamMc331 there are two conditions:

• Should be Gradle root project
• Should exits .git folder
  see

  ktlint-gradle/plugin/src/main/kotlin/org/jlleitschuh/gradle/ktlint/GitHook.kt

  Line 56 in 14aaba9

  if (target.rootProject == target &&

I would say possible logic adjustment could be done:

• always add git hook tasks to Gradle root project
• if there is not .git/ folder available - fail the task
• optionally allow to pass .git/ folder location via -PktlintGitRoot= flag

[Tapchicoma]

Opened more specific git hook enhancement issues and closing this one as initial implementation was added back ago.

If you want to propose some additional git-hook enhancement, please open a separate issue for it.

[Rubyj]

@Tapchicoma Is there any way to have this pre commit hook installed by default? I am trying to eliminated the need for developers to actually run this command to activate the pre-commit hook. I want it to be activated for them.

Or, maybe a way to add this to be in the build step?

[Tapchicoma]

Or, maybe a way to add this to be in the build step?

IMHO, doesn't make sense to install this githook on every build (though task itself is cacheable).

I am not aware of any way how to install it automatically. I would say you should run ktlint on your CI setup and maybe create a "proxy" task "projectSetup" that will trigger commit hook installation task (probably some more related to setup tasks as well).

[Tapchicoma]

@AdamMc331 interesting usage of "clean" task. Have you noticed that some developers are not using it?

[AdamMc331]

I think it's rare that a developer doesn't run a clean build at some point. On our small team of five people though it was never an issue, but I guess there's potential that someone might not get the git hooks installed right away.

It's very similar to your suggestion of a projectSetup task except now it's one that's potentially built in to a normal day's workflow - and certainly for someone cloning a project for the first time.