How to Add Pre/post-Commit Hooks to Your Node.js Project

As the project grows larger it's critical for the whole team to follow certain code quality and security standards. One way to ensure that is by using "git hooks".

Git hooks are scripts that run automatically every time a particular event occurs in a Git repository.

Numerous git hook managers are available for Node.js. Husky, pre-commit, and Lefthook are a few examples of such tools. We opted for Lefthook for this tutorial due to its capability to execute scripts concurrently and its simplicity.

So let's start!

Before each commit(pre-commit) we need to ensure the following.

No credentials leak: To ensure no secrets are accidentally exposed in the source.
No lint errors: The committed code does not contain any lint errors (eslint).
No formatting inconsistencies: The committed code should follow the organization's code formatting standards(prettier or pretty-quick).
No type errors: There shouldn't be any typescript errors.

And on each pre-push we need to ensure the following

No vulnerable packages: npm audit or pnpm audit --audit-level high
Standardized branch-names: we can usevalidate-branch-name

Apart from these we also need to enforce standards for all our commit messages(commit-lint).

GitLeaks

install gitleaks in your machine gitleaks

add the following changes to your package.json

{
   "scripts":{
+      "gitleaks": "gitleaks detect -v"
    }

}

Eslint

install and configure eslint with

npm init @eslint/config

add the following changes to your package.json

{
   "scripts":{
+      "lint": "eslint --ignore-path .gitignore \"{src,tests}/**/*.+(ts|js|tsx)\"",
    }

}

Typecheck

{
   "scripts":{
+      "typecheck": "tsc --noEmit",
    }

}

Prettier for code formatting

npm install --save-dev --save-exact prettier

Package.json

{
   "scripts":{
+      "format": "prettier --ignore-path .prettierignore --write \"**/*.+(js|ts|json|tsx|mdx)\" --log-level silent",
    }

}

Branch name validations

npm i validate-branch-name -D

Package.json

{
   "validate-branch-name": {
        "pattern": "^(feat|fix|hotfix|release|test|experimental)/.+$",
        "errorMsg": "Branch name validation failed"
    },

}

Commit lint for standardized commit messages

npm i @commitlint/cli -D
npm i @commitlint/config-conventional -D

create the file commitlint.config.js at the root

module.exports = {
    extends: ['@commitlint/config-conventional'], // => @commitlint/config-conventional
};

create the file .lefthook/commit-msg/commitlint.sh

echo $(head -n1 $1) | npx commitlint --color

Lefthook as githooks manager

// install lefthook
npm install lefthook --save-dev

# create a lefthook.yml file in the root
pre-commit:
  parallel: true
  commands:
    lint:
      glob: '*.{js,ts,jsx,tsx}' # glob filter for list of files
      run: npm run lint
    format:
      run: npm run format 
    types:
      glob: '*.{js,ts, jsx, tsx}'
      run: npm run typecheck
    gitLeaks:
      run: npm run gitleaks
pre-push:
  parallel: true
  commands:
    branchName:
      run: npx validate-branch-name
    packages-audit:
      tags: frontend security
      run: npm audit
commit-msg:
  parallel: true
  scripts:
    "commitlint.sh":
      runner: bash

package.json

{
   "scripts":{
+     "prepare": "lefthook install",
    }
}

Run lefthook install and try making your first commit.

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