Fix linting rule and add lint to workflow

.babelrc

@@ -9,6 +9,7 @@
               "node": "8"
             },
             "useBuiltIns": "usage",
+            "corejs": 3,
             "loose": true
           }
         ]
@@ -25,6 +26,7 @@
               "node": "4"
             },
             "useBuiltIns": "usage",
+            "corejs": 3,
             "loose": true
           }
         ]

.eslintignore

@@ -0,0 +1,4 @@
+flow-typed/
+lib/
+node_modules/
+dist/

.eslintrc.js

@@ -1,17 +1,18 @@
 module.exports = {
+  root: true,
   env: {
     es6: true,
     node: true,
     'jest/globals': true,
   },
-  extends: ['eslint:recommended', 'plugin:jest/recommended', 'prettier'],
+  extends: [
+    'eslint:recommended',
+    'plugin:jest/recommended',
+    'plugin:prettier/recommended',
+  ],
   plugins: ['jest'],
   parserOptions: {
-    ecmaVersion: 2017,
+    ecmaVersion: 2018,
     sourceType: 'module',
-    ecmaFeatures: {
-      experimentalObjectRestSpread: true,
-    },
   },
-  rules: {},
 };

.github/workflows/main.yml

@@ -33,3 +33,22 @@ jobs:
         if: matrix.node-version == '12.x'
         env:
           CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+
+      - name: Use Node.js 10.x
+        uses: actions/setup-node@v1
+        with:
+          node-version: 10.x
+
+      - name: Install Yarn
+        run: curl -o- -L https://yarnpkg.com/install.sh | bash
+
+      - name: Install Dependencies
+        run: yarn install --frozen-lockfile
+
+      - name: Run ESLint
+        run: yarn eslint .

.prettierrc

@@ -0,0 +1,4 @@
+{
+  "singleQuote": true,
+  "trailingComma": "es5"
+}

package.json

@@ -44,6 +44,7 @@
     "eslint": "^6.3.0",
     "eslint-config-prettier": "^6.2.0",
     "eslint-plugin-jest": "^22.17.0",
+    "eslint-plugin-prettier": "^3.1.0",
     "flow-bin": "^0.107.0",
     "husky": "^3.0.5",
     "jest": "^24.9.0",
@@ -59,7 +60,7 @@
     "build": "yarn run clean && yarn build:modern && yarn build:legacy",
     "build:modern": "BABEL_ENV=modern babel src -d lib/modern/",
     "build:legacy": "BABEL_ENV=legacy babel src -d lib/legacy",
-    "prepare": "yarn build",
+    "prepublishOnly": "yarn build",
     "format": "prettier --write src/*.js src/**/*.js",
     "test": "jest",
     "test-ci": "jest --coverage --colors"
@@ -68,9 +69,5 @@
     "testMatch": [
       "<rootDir>/src/**/__tests__/**/*.js"
     ]
-  },
-  "prettier": {
-    "singleQuote": true,
-    "trailingComma": "es5"
   }
 }

src/validation-errors/additional-prop.js

@@ -13,9 +13,7 @@ export default class AdditionalPropValidationError extends BaseValidationError {
 
     return output.concat(
       this.getCodeFrame(
-        chalk`😲  {magentaBright ${
-          params.additionalProperty
-        }} is not expected to be here!`,
+        chalk`😲  {magentaBright ${params.additionalProperty}} is not expected to be here!`,
         `${dataPath}/${params.additionalProperty}`
       )
     );

src/validation-errors/enum.js

@@ -60,8 +60,8 @@ export default class EnumValidationError extends BaseValidationError {
         value,
         weight: leven(value, currentValue.toString()),
       }))
-      .sort(
-        (x, y) => (x.weight > y.weight ? 1 : x.weight < y.weight ? -1 : 0)
+      .sort((x, y) =>
+        x.weight > y.weight ? 1 : x.weight < y.weight ? -1 : 0
       )[0];
 
     return allowedValues.length === 1 ||

yarn.lock

@@ -1758,6 +1758,13 @@ eslint-plugin-jest@^22.17.0:
   dependencies:
     "@typescript-eslint/experimental-utils" "^1.13.0"
 
+eslint-plugin-prettier@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/eslint-plugin-prettier/-/eslint-plugin-prettier-3.1.0.tgz#8695188f95daa93b0dc54b249347ca3b79c4686d"
+  integrity sha512-XWX2yVuwVNLOUhQijAkXz+rMPPoCr7WFiAl8ig6I7Xn+pPVhDhzg4DxHpmbeb0iqjO9UronEA3Tb09ChnFVHHA==
+  dependencies:
+    prettier-linter-helpers "^1.0.0"
+
 eslint-scope@^4.0.0:
   version "4.0.3"
   resolved "https://registry.yarnpkg.com/eslint-scope/-/eslint-scope-4.0.3.tgz#ca03833310f6889a3264781aa82e63eb9cfe7848"
@@ -1994,6 +2001,11 @@ fast-deep-equal@^2.0.1:
   resolved "https://registry.yarnpkg.com/fast-deep-equal/-/fast-deep-equal-2.0.1.tgz#7b05218ddf9667bf7f370bf7fdb2cb15fdd0aa49"
   integrity sha1-ewUhjd+WZ79/Nwv3/bLLFf3Qqkk=
 
+fast-diff@^1.1.2:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/fast-diff/-/fast-diff-1.2.0.tgz#73ee11982d86caaf7959828d519cfe927fac5f03"
+  integrity sha512-xJuoT5+L99XlZ8twedaRf6Ax2TgQVxvgZOYoPKqZufmJib0tL2tegPBOZb1pVNgIhlqDlA0eO0c3wBvQcmzx4w==
+
 fast-json-stable-stringify@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/fast-json-stable-stringify/-/fast-json-stable-stringify-2.0.0.tgz#d5142c0caee6b1189f87d3a76111064f86c8bbf2"
@@ -3943,6 +3955,13 @@ prelude-ls@~1.1.2:
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.1.2.tgz#21932a549f5e52ffd9a827f570e04be62a97da54"
   integrity sha1-IZMqVJ9eUv/ZqCf1cOBL5iqX2lQ=
 
+prettier-linter-helpers@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/prettier-linter-helpers/-/prettier-linter-helpers-1.0.0.tgz#d23d41fe1375646de2d0104d3454a3008802cf7b"
+  integrity sha512-GbK2cP9nraSSUF9N2XwUwqfzlAFlMNYYl+ShE/V+H8a9uNl/oUqB1w2EL54Jh0OlyRSd8RfWYJ3coVS4TROP2w==
+  dependencies:
+    fast-diff "^1.1.2"
+
 prettier@^1.14.2:
   version "1.18.2"
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.18.2.tgz#6823e7c5900017b4bd3acf46fe9ac4b4d7bda9ea"