From 848c7aa1e4d2966467f6ad6cd8d802f824d00245 Mon Sep 17 00:00:00 2001
From: "Kent C. Dodds" <kent+github@doddsfamily.us>
Date: Thu, 12 Oct 2017 16:30:04 -0600
Subject: [PATCH] feat: add opt-out capability for the auto-formatting (#6)

---
 CONTRIBUTING.md                      | 12 +++++++-
 src/config/__tests__/lintstagedrc.js | 41 ++++++++++++++++++++++++++++
 src/config/lintstagedrc.js           |  8 +++---
 src/scripts/precommit/index.js       | 13 ++-------
 src/utils.js                         | 18 ++++++++++++
 5 files changed, 76 insertions(+), 16 deletions(-)
 create mode 100644 src/config/__tests__/lintstagedrc.js

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 0ca9c187..960ff204 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -55,7 +55,7 @@ Please make sure to run the tests before you commit your changes. You can run
 `npm run test:update` which will update any snapshots that need updating.
 Make sure to include those changes (if they exist) in your commit.
 
-### opt into git hooks
+### opt in/out of git hooks
 
 There are git hooks set up with this project that are automatically installed
 when you install dependencies. They're really handy, but are turned off by
@@ -67,6 +67,16 @@ inside:
 pre-commit
 ```
 
+One of the things that the git hooks does is automatically format the files you
+change. It does this by reformating the entire file and running `git add` on
+the file after. This breaks workflows where you're trying to commit portions of
+the file only. You can always run your commit with `--no-verify`, but if this
+is a bummer to your workflow, you can add an `.opt-out` file with the contents:
+
+```
+autoformat
+```
+
 ## Help needed
 
 Please checkout the [the open issues][issues]
diff --git a/src/config/__tests__/lintstagedrc.js b/src/config/__tests__/lintstagedrc.js
new file mode 100644
index 00000000..142dcfc6
--- /dev/null
+++ b/src/config/__tests__/lintstagedrc.js
@@ -0,0 +1,41 @@
+import * as utilsMock from '../../utils'
+
+jest.mock('../../utils', () => ({
+  ...require.requireActual('../../utils'),
+  isOptedOut: jest.fn((key, t) => t),
+}))
+
+afterEach(() => {
+  jest.resetModules()
+})
+
+test('includes format and git add when not opted out', () => {
+  utilsMock.isOptedOut.mockImplementation((key, t, f) => f)
+  const config = require('../lintstagedrc')
+  const jsLinter = getJsLinter(config.linters)
+  expect(hasFormat(jsLinter)).toBe(true)
+  expect(hasGitAdd(jsLinter)).toBe(true)
+})
+
+test('does not include format and git add when opted out', () => {
+  utilsMock.isOptedOut.mockImplementation((key, t) => t)
+  const config = require('../lintstagedrc')
+  const jsLinter = getJsLinter(config.linters)
+  expect(hasFormat(jsLinter)).toBe(false)
+  expect(hasGitAdd(jsLinter)).toBe(false)
+})
+
+function hasFormat(linter) {
+  return linter.some(l => l.includes('format'))
+}
+
+function hasGitAdd(linter) {
+  return linter.includes('git add')
+}
+
+function getJsLinter(linters) {
+  const key = Object.keys(linters).find(
+    k => k.includes('**') && k.includes('js'),
+  )
+  return linters[key]
+}
diff --git a/src/config/lintstagedrc.js b/src/config/lintstagedrc.js
index 1d39798c..ca3997e1 100644
--- a/src/config/lintstagedrc.js
+++ b/src/config/lintstagedrc.js
@@ -1,4 +1,4 @@
-const {resolveKcdScripts, resolveBin} = require('../utils')
+const {resolveKcdScripts, resolveBin, isOptedOut} = require('../utils')
 
 const kcdScripts = resolveKcdScripts()
 const doctoc = resolveBin('doctoc')
@@ -7,11 +7,11 @@ module.exports = {
   concurrent: false,
   linters: {
     '**/*.+(js|json|less|css|ts)': [
-      `${kcdScripts} format`,
+      isOptedOut('autoformat', null, `${kcdScripts} format`),
       `${kcdScripts} lint`,
       `${kcdScripts} test --findRelatedTests`,
-      'git add',
-    ],
+      isOptedOut('autoformat', null, 'git add'),
+    ].filter(Boolean),
     '.all-contributorsrc': [
       `${kcdScripts} contributors generate`,
       'git add README.md',
diff --git a/src/scripts/precommit/index.js b/src/scripts/precommit/index.js
index ba8a779d..991456d5 100644
--- a/src/scripts/precommit/index.js
+++ b/src/scripts/precommit/index.js
@@ -1,6 +1,5 @@
-const fs = require('fs')
 const spawn = require('cross-spawn')
-const {fromRoot} = require('../../utils')
+const {isOptedIn} = require('../../utils')
 
 const [executor, ...args] = process.argv
 
@@ -10,7 +9,7 @@ const lintStagedResult = spawn.sync(
   {stdio: 'inherit'},
 )
 
-if (lintStagedResult.status !== 0 || !isOptedIntoValidate()) {
+if (lintStagedResult.status !== 0 || !isOptedIn('pre-commit')) {
   process.exit(lintStagedResult.status)
 } else {
   const validateResult = spawn.sync('npm', ['run', 'validate'], {
@@ -19,11 +18,3 @@ if (lintStagedResult.status !== 0 || !isOptedIntoValidate()) {
 
   process.exit(validateResult.status)
 }
-
-function isOptedIntoValidate() {
-  if (!fs.existsSync(fromRoot('.opt-in'))) {
-    return false
-  }
-  const contents = fs.readFileSync(fromRoot('.opt-in'), 'utf-8')
-  return contents.includes('pre-commit')
-}
diff --git a/src/utils.js b/src/utils.js
index dc49e0dd..b2d47ca3 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -115,7 +115,25 @@ function getConcurrentlyArgs(scripts, {killOthers = true} = {}) {
   ].filter(Boolean)
 }
 
+function isOptedOut(key, t = true, f = false) {
+  if (!fs.existsSync(fromRoot('.opt-out'))) {
+    return f
+  }
+  const contents = fs.readFileSync(fromRoot('.opt-out'), 'utf-8')
+  return contents.includes(key) ? t : f
+}
+
+function isOptedIn(key, t = true, f = false) {
+  if (!fs.existsSync(fromRoot('.opt-in'))) {
+    return f
+  }
+  const contents = fs.readFileSync(fromRoot('.opt-in'), 'utf-8')
+  return contents.includes(key) ? t : f
+}
+
 module.exports = {
+  isOptedOut,
+  isOptedIn,
   ifDevDep,
   ifPeerDep,
   ifScript,