chore: convert to import/export (#302)

Author: SimenB

.eslintrc.js

@@ -9,9 +9,9 @@ module.exports = {
     'plugin:node/recommended',
     'prettier',
   ],
-  plugins: ['eslint-plugin', 'node', 'prettier'],
+  plugins: ['eslint-plugin', 'node', 'prettier', 'import'],
   parserOptions: {
-    ecmaVersion: 2017,
+    ecmaVersion: 2018,
   },
   env: {
     node: true,
@@ -24,21 +24,30 @@ module.exports = {
     'object-shorthand': ['warn', 'always', { avoidExplicitReturnArrows: true }],
     'prefer-destructuring': [
       'error',
-      {
-        VariableDeclarator: {
-          array: true,
-          object: true,
-        },
-      },
+      { VariableDeclarator: { array: true, object: true } },
     ],
     'prettier/prettier': 'error',
     'node/no-unsupported-features/es-syntax': 'off',
     'node/no-unsupported-features/es-builtins': 'error',
+    'import/no-commonjs': 'error',
+    'import/no-unused-modules': 'error',
   },
   overrides: [
     {
       files: ['*.test.js'],
       globals,
     },
+    {
+      files: 'src/**/*',
+      parserOptions: {
+        sourceType: 'module',
+      },
+    },
+    {
+      files: ['.eslintrc.js', 'babel.config.js'],
+      rules: {
+        'import/no-commonjs': 'off',
+      },
+    },
   ],
 };

package.json

@@ -45,6 +45,7 @@
     "eslint": "^5.1.0",
     "eslint-config-prettier": "^5.1.0",
     "eslint-plugin-eslint-plugin": "^2.0.0",
+    "eslint-plugin-import": "^2.18.0",
     "eslint-plugin-node": "^8.0.0",
     "eslint-plugin-prettier": "^3.0.0",
     "husky": "^1.0.1",

src/__tests__/rules.test.js

@@ -1,18 +1,16 @@
-'use strict';
-
-const fs = require('fs');
-const path = require('path');
-const { rules } = require('../');
+import { existsSync } from 'fs';
+import { resolve } from 'path';
+import { rules } from '../';
 
 const ruleNames = Object.keys(rules);
 const numberOfRules = 33;
 
 describe('rules', () => {
   it('should have a corresponding doc for each rule', () => {
     ruleNames.forEach(rule => {
-      const docPath = path.resolve(__dirname, '../../docs/rules', `${rule}.md`);
+      const docPath = resolve(__dirname, '../../docs/rules', `${rule}.md`);
 
-      if (!fs.existsSync(docPath)) {
+      if (!existsSync(docPath)) {
         throw new Error(
           `Could not find documentation file for rule "${rule}" in path "${docPath}"`,
         );

src/index.js

@@ -1,23 +1,31 @@
-'use strict';
+import { readdirSync } from 'fs';
+import { basename, join } from 'path';
+import * as snapshotProcessor from './processors/snapshot-processor';
 
-const fs = require('fs');
-const path = require('path');
+// copied from https://github.com/babel/babel/blob/d8da63c929f2d28c401571e2a43166678c555bc4/packages/babel-helpers/src/helpers.js#L602-L606
+/* istanbul ignore next */
+function interopRequireDefault(obj) {
+  return obj && obj.__esModule ? obj : { default: obj };
+}
 
-const rules = fs
-  .readdirSync(path.join(__dirname, 'rules'))
+function importDefault(moduleName) {
+  return interopRequireDefault(require(moduleName)).default;
+}
+
+const rules = readdirSync(join(__dirname, 'rules'))
   .filter(rule => rule !== '__tests__' && rule !== 'util.js')
-  .map(rule => path.basename(rule, '.js'))
+  .map(rule => basename(rule, '.js'))
   .reduce(
-    (acc, curr) => Object.assign(acc, { [curr]: require(`./rules/${curr}`) }),
+    (acc, curr) =>
+      Object.assign(acc, { [curr]: importDefault(`./rules/${curr}`) }),
     {},
   );
 let allRules = {};
 Object.keys(rules).forEach(function(key) {
   allRules[`jest/${key}`] = 'error';
 });
 
-const snapshotProcessor = require('./processors/snapshot-processor');
-
+// eslint-disable-next-line import/no-commonjs
 module.exports = {
   configs: {
     all: {

src/processors/__tests__/snapshot-processor.test.js

@@ -1,6 +1,4 @@
-'use strict';
-
-const snapshotProcessor = require('../snapshot-processor');
+import * as snapshotProcessor from '../snapshot-processor';
 
 describe('snapshot-processor', () => {
   it('exports an object with preprocess and postprocess functions', () => {

src/processors/snapshot-processor.js

@@ -1,15 +1,8 @@
-'use strict';
-
 // https://eslint.org/docs/developer-guide/working-with-plugins#processors-in-plugins
-const preprocess = source => [source];
+export const preprocess = source => [source];
 
-const postprocess = messages =>
+export const postprocess = messages =>
   messages[0].filter(
     // snapshot files should only be linted with snapshot specific rules
     message => message.ruleId === 'jest/no-large-snapshots',
   );
-
-module.exports = {
-  preprocess,
-  postprocess,
-};

src/rules/__tests__/consistent-test-it.test.js

@@ -1,7 +1,5 @@
-'use strict';
-
-const { RuleTester } = require('eslint');
-const rule = require('../consistent-test-it');
+import { RuleTester } from 'eslint';
+import rule from '../consistent-test-it';
 
 const ruleTester = new RuleTester({
   parserOptions: {

src/rules/__tests__/expect-expect.test.js

@@ -1,7 +1,5 @@
-'use strict';
-
-const { RuleTester } = require('eslint');
-const rule = require('../expect-expect');
+import { RuleTester } from 'eslint';
+import rule from '../expect-expect';
 
 const ruleTester = new RuleTester({
   parserOptions: {

src/rules/__tests__/lowercase-name.test.js

@@ -1,7 +1,5 @@
-'use strict';
-
-const { RuleTester } = require('eslint');
-const rule = require('../lowercase-name');
+import { RuleTester } from 'eslint';
+import rule from '../lowercase-name';
 
 const ruleTester = new RuleTester({
   parserOptions: {

src/rules/__tests__/no-alias-methods.test.js

@@ -1,7 +1,5 @@
-'use strict';
-
-const { RuleTester } = require('eslint');
-const rule = require('../no-alias-methods');
+import { RuleTester } from 'eslint';
+import rule from '../no-alias-methods';
 
 const ruleTester = new RuleTester();