Add HUSKY_SKIP_HOOKS env var to skip running hooks (#492)

* Add HUSKY_SKIP_HOOKS env var to skip running hooks

* Add test for HUSKY_SKIP_HOOKS

* Add documentation for HUSKY_SKIP_HOOKS

.travis.yml

@@ -17,6 +17,10 @@ script:
   - cat .git/hooks/post-checkout
   - time git checkout
   - node scripts/ci-post-checkout-check
+  # Test HUSKY_SKIP_HOOKS
+  - cat .git/hooks/post-checkout
+  - HUSKY_SKIP_HOOKS=1 time git checkout
+  - node scripts/ci-husky-skip-hooks
   # Should not fail due to missing script
   - node scripts/ci-break-path.js
   - cat .git/hooks/post-checkout

DOCS.md

@@ -28,6 +28,14 @@ If you don't want `husky` to automatically install Git hooks, simply set `HUSKY_
 HUSKY_SKIP_INSTALL=1 npm install
 ```
 
+## Skip running hooks
+
+If you don't want `husky` to run your hooks, simply set `HUSKY_SKIP_HOOKS` environment variable to `1`.
+
+```sh
+HUSKY_SKIP_HOOKS=1 git checkout
+```
+
 ## Multi-package repository (monorepo)
 
 If you have a multi-package repository, it's __recommended__ to use tools like [lerna](https://github.com/lerna/lerna) and have `husky` installed ONLY in the root `package.json` to act as the source of truth.

scripts/ci-husky-skip-hooks.js

@@ -0,0 +1,25 @@
+/* eslint-disable @typescript-eslint/no-var-requires */
+const fs = require('fs')
+const path = require('path')
+
+const filename = path.join(__dirname, '../ci-post-checkout')
+
+if (fs.existsSync(filename)) {
+  const data = fs.readFileSync(filename, 'utf-8')
+
+  if (data.split(' ').length !== 3) {
+    console.log('Not all params were set in HUSKY_GIT_PARAMS')
+    console.log('Got', data)
+    process.exit(1)
+  }
+
+  fs.unlinkSync(filename)
+  console.log(
+    '.git/hooks/post-checkout script has run, hooks were not skipped.'
+  )
+  process.exit(1)
+} else {
+  console.log(
+    '.git/hooks/post-checkout script has not run, hooks were successfully skipped.'
+  )
+}

src/runner/index.ts

@@ -7,6 +7,7 @@ import getConf from '../getConf'
 export interface Env extends NodeJS.ProcessEnv {
   HUSKY_GIT_STDIN?: string
   HUSKY_GIT_PARAMS?: string
+  HUSKY_SKIP_HOOKS?: string
 }
 
 /**
@@ -17,6 +18,17 @@ export default async function run(
   [, scriptPath, hookName = '', HUSKY_GIT_PARAMS]: string[],
   getStdinFn: () => Promise<string> = getStdin
 ): Promise<number> {
+  if (
+    process.env.HUSKY_SKIP_HOOKS === 'true' ||
+    process.env.HUSKY_SKIP_HOOKS === '1'
+  ) {
+    console.log(
+      "HUSKY_SKIP_HOOKS environment variable is set to 'true',",
+      'skipping running Git hooks.'
+    )
+    return 0
+  }
+
   const cwd = path.resolve(scriptPath.split('node_modules')[0])
   // In some cases, package.json may not exist
   // For example, when switching to gh-page branch