An example of creating a lint check before each git commit.

Creating Gradle tasks that read scripts

// Task to be added in root built.gradle

task installGitHook(type: Copy) {
    from new File(rootProject.rootDir, 'pre-commit')
    into { new File(rootProject.rootDir, '.git/hooks') }
    fileMode 0777
}
tasks.getByPath(':app:preBuild').dependsOn installGitHook
------------------------------------------------------------
#script to be added to pre-commit file in project root
#!/bin/bash
set -e
echo "*******************************"
echo  (~˘▾˘)~ "Running linter" ~(˘▾˘~)
echo "*******************************"

git stash -q --keep-index

./gradlew ktlint --continue

RESULT=$?

git stash pop -q

# return 1 exit code if running checks fails
[ $RESULT -ne 0 ] && exit 1
exit 0
-----------------------------------------

Copy - Copies files into a destination directory. This task can also rename and filter files as it copies. The task implements CopySpec for specifying what to copy.

https://docs.gradle.org/current/javadoc/org/gradle/api/tasks/Copy.html

    from new File(rootProject.rootDir, 'pre-commit')
    into { new File(rootProject.rootDir, '.git/hooks') }

This looks for a file in my root directory named 'pre-commit' and adds it to the directory '.git/hooks'. The hooks are all stored in the hooks subdirectory of the Git directory. In most projects, by default it'll be in this location .git/hooks.

Git hooks are scripts that run automatically every time a particular event occurs in a Git repository. They let you customize Git's internal behavior and trigger customizable actions at key points in the development life cycle.

fileMode 0777 file permission equivalent of CHMOD777

preBuild will be automatically called before build task.

https://github.com/pinterest/ktlint Linting Library used