prettier --list-different

.eslintrc

@@ -6,13 +6,9 @@
       "jsx": true
     }
   },
+  "extends": ["eslint:recommended", "eslint-config-prettier"],
   "rules": {
-    "strict": ["error", "never"],
-    "valid-typeof": "error",
-    "no-unsafe-negation": "error",
-    "no-unused-vars": "error",
-    "no-unexpected-multiline": "error",
-    "no-undef": "error"
+    "strict": ["error", "never"]
   },
   "env": {
     "browser": true

.prettierrc

@@ -0,0 +1,17 @@
+{
+  "arrowParens": "avoid",
+  "bracketSpacing": false,
+  "htmlWhitespaceSensitivity": "css",
+  "insertPragma": false,
+  "jsxBracketSameLine": false,
+  "jsxSingleQuote": false,
+  "printWidth": 80,
+  "proseWrap": "always",
+  "quoteProps": "as-needed",
+  "requirePragma": false,
+  "semi": false,
+  "singleQuote": true,
+  "tabWidth": 2,
+  "trailingComma": "all",
+  "useTabs": false
+}

package-lock.json

@@ -1503,6 +1503,15 @@
         }
       }
     },
+    "eslint-config-prettier": {
+      "version": "6.5.0",
+      "resolved": "https://registry.npmjs.org/eslint-config-prettier/-/eslint-config-prettier-6.5.0.tgz",
+      "integrity": "sha512-cjXp8SbO9VFGW/Z7mbTydqS9to8Z58E5aYhj3e1+Hx7lS9s6gL5ILKNpCqZAFOVYRcSkWPFYljHrEh8QFEK5EQ==",
+      "dev": true,
+      "requires": {
+        "get-stdin": "^6.0.0"
+      }
+    },
     "eslint-scope": {
       "version": "5.0.0",
       "resolved": "https://registry.npmjs.org/eslint-scope/-/eslint-scope-5.0.0.tgz",
@@ -2385,6 +2394,12 @@
       "integrity": "sha1-GwqzvVU7Kg1jmdKcDj6gslIHgyc=",
       "dev": true
     },
+    "get-stdin": {
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/get-stdin/-/get-stdin-6.0.0.tgz",
+      "integrity": "sha512-jp4tHawyV7+fkkSKyvjuLZswblUtz+SQKzSWnBbii16BuZksJlU1wuBYXY75r+duh/llF1ur6oNwi+2ZzjKZ7g==",
+      "dev": true
+    },
     "get-value": {
       "version": "2.0.6",
       "resolved": "https://registry.npmjs.org/get-value/-/get-value-2.0.6.tgz",
@@ -3178,6 +3193,12 @@
       "integrity": "sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ=",
       "dev": true
     },
+    "prettier": {
+      "version": "1.19.1",
+      "resolved": "https://registry.npmjs.org/prettier/-/prettier-1.19.1.tgz",
+      "integrity": "sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==",
+      "dev": true
+    },
     "private": {
       "version": "0.1.8",
       "resolved": "https://registry.npmjs.org/private/-/private-0.1.8.tgz",

package.json

@@ -4,12 +4,19 @@
   "author": "Kent C. Dodds (http://kentcdodds.com/)",
   "license": "GPLv3",
   "scripts": {
-    "build": "babel src --out-dir dist"
+    "build": "babel src --out-dir dist",
+    "lint": "eslint --ignore-path .gitignore .",
+    "prettier": "prettier --ignore-path .gitignore \"**/*.+(js|json)\"",
+    "format": "npm run prettier -- --write",
+    "check-format": "npm run prettier -- --list-different",
+    "validate": "npm run check-format && npm run lint && npm run build"
   },
   "devDependencies": {
     "@babel/cli": "^7.7.0",
     "@babel/core": "^7.7.2",
     "@babel/preset-env": "^7.7.1",
-    "eslint": "^6.6.0"
+    "eslint": "^6.6.0",
+    "eslint-config-prettier": "^6.5.0",
+    "prettier": "^1.19.1"
   }
 }

src/example.js

@@ -1,12 +1,10 @@
-'use strict'
-
 const username = 'freddy'
-typeof username === 'strng'
+typeof username === 'string'
 
-if (!'serviceWorker' in navigator) {
+if (!('serviceWorker' in navigator)) {
   // you have an old browser :-(
 }
 
 const greeting = 'hello'
-console.log('${greeting} world!')
-[1, 2, 3].forEach(x => console.log(x))
+console.log(`${greeting} world!`)
+;[1, 2, 3].forEach(x => console.log(x))