4 best tools to implement for your githooks in an Android project.

Git Hooks are programs that you can place in a your .git/hooks/ directory to trigger actions at certain points in Git’s execution. These scripts are the best enablers for increasing the quality of your codebase or your productivity. Here is my selection of the best tools to use in your hooks that we use at Shopmium. You can find also which tools we use on iOS in our hooks here. I will present hooks code sample about :

• Ktlint -F (Formatter part)
• Detekt : Kotlin linter
• AndroidLint : Android framework linter
• Terminal-notifier: Get notified after checks failed or succeeded
• Bonus: How to generate Detekt and Android baseline files

#1 Ktlint — -F the mandatory one

Ktlint is the #1 tool you should put in your git-hook pre-commit. Ktlint allows you to format Kotlint source code and the available options and configuration make this tool very flexible and powerful, on demand. This tool should NOT be used on the CI side, it’s not the job of the CI at all to format your source code. Incorporating this into Android Studio has several drawbacks.

• Slowing down the build just for formatting
• Seeing your code moving at each build 👀

Because we use Detekt for linting the Kotlint source code, we only use ktlint -F (autoreformatter part). Sample of pre-commit with Ktlint usage:

#2 Detekt — The second mandatory one

Dealing with a linter is mandatory and no developer should push code smells. Adding Detekt at the pre-commit level acts as a gate, in addition to using it in Android Studio with the awesome Detekt plugin. Moreover Detekt has a baseline system (Swiftlint on iOS doesn’t support baseline yet but this article explains how to workaround).

• I don’t use gradle task for it, only Android plugin for background analysis with your baseline and Detekt configuration rules. You will have no overhead on build time / CI side.
• To generate the baseline jump at the end of this article ⬇️

Detekt exit status code is != 0 if some warnings are found, here is how pre-commit could looks like :

#3 AndroidLint — Framework linter

Android-lint is a powerful tool that everyproject have to run in order to detect dead code, bad practices, security issues, basic memory leaks, etc...

#4 Terminal-notifier — Take ☕️ and get notified

With all these tools above, pre-commit of pre-push could take time to finish, in addition to your own tools added. Terminal-notifier is a command line that allow to trigger a notification from the Macos Notification center. You will be able to commit, take your ☕️ , read teammates PR and get notified when pre-commit checks finished with success or fail !

• Execute script on success or failure when tap on notification or open an app
• Change the sound
• Many more capabilities on the official documentation

Thank you for reading this article. If you know more tools that could be awesome to add in a githooks (commit, push or whatever) tell me in comment. If you enjoyed it, you can 👏 me, and if you want to see more content, you can follow me 🚀.

Bonus: How to generate Detekt and Android baseline files

Baseline are use to create a fixed configuration file when you are starting to use a tools with huge legacy (so, with many warnings) to start from a new line, you must generate a baseline.

Detekt: Run in the terminal:

$ detekt --baseline baseline.xml --create-baseline -c detekt.yml

Android lint: In your app/build.gradle, add the following:

android {
    lint {
        baseline = file("lint-baseline.xml")
    }
}

then run in the terminal:

$ ./gradlew lint

Wanna contribute? If you know more tools that could be awesome, productive to add in a githook (commit, push or whatever) share it in comment. If you enjoyed the quality of this article, you can 👏 me, and if you want to see more content, you can follow me 🚀.