vagrant

In a previous article I discussed about automatically applying the PSR-2 coding standard using a Git pre-commit hook. In that post, I wrote about the importance of making sure these standards were followed, but also about how to make this easy for the developers.

At the time I was working on this, we had a number of things happening in our repo/.git/hooks/pre-commit file. When a new developer joined the team we had to make sure they added the hooks, alongside everything else. I was sure we could do better here.

The solution I implemented was to leverage the power of Composer scripts. When working on a shared PHP application, best practice informs that the composer.lock file should be version controlled. This way, each developer will be using the exact same version of each library (assuming they’re on the same branch). Change branch, run composer install and you’re all good.

A less well used feature of Composer in the scripts section, and the corresponding events. Given the first thing a new developer will do is run composer install this seemed to make sense as the starting point for applying our hooks. I added a shell script that would run following the install command and symlink the directory containing our hooks into the repo hooks.

  {
    "require-dev": {
      "dealerdirect/phpcodesniffer-composer-installer": "^0.4.4",
      "wimg/php-compatibility": "^8.1"
    },
    "scripts": {
      "post-install-cmd": [
        "./scripts/symlink.sh"
      ]
    }
  }
  #!/bin/sh
  if [ ! -L .git/hooks ];
  then
      echo ".git/hooks is not symlink"
      echo "copying .git/hooks to .git/old_hooks"
      mv .git/hooks .git/old_hooks

      echo "symlinking ../scripts/git-hooks .git/hooks"
      ln -s ../scripts/git-hooks .git/hooks
  else
      echo ".git/hooks is already a symlink"
  fi

The first step was adding these hooks as a set of individual files within repo/scripts/git-hooks. This meant each hook could be encapsulated individually. These in turn would be loaded through the pre-commit file:

  #!/bin/bash

  currentdir="${0%/*}"

  source ${currentdir}/hooks/commit_guard.sh
  source ${currentdir}/hooks/coding_style.sh

  exit 0

In this way, we enforced the psr2 check, and another hook we were already using to prevent commits on branches that can only be updated via pull requests.