refactor: Update test environments and lint configuration (#1736)

* Update test environments and lint configuration

Update Jest (unit + integration) and Playwright (e2e) test environments. Includes stability improvements for e2e tests using newer, more stable methods per the Playwright docs.

- Update Jest 26 => 27
- Update Jest-related libs (babel parser)
- Update Playwright 1.8 => Playwright Test 1.18
- Update GitHub CI (action versions, job parallelization, and matrices)
- Update ESLint 5 => 8
- Update ESLint-related libs (parser, prettier, Jest, Playwright)
- Fix test failures on M1-based Macs
- Fix e2e stability issues by replacing PW $ method calls
- Fix ESLint errors
- Fix incorrect CI flag on Jest runs (-ci => --ci)
- Refactor e2e test runner from Jest to Playwright Test
- Refactor e2e test files for Playwright Test
- Refactor fix-lint script name to lint:fix for consistency
- Refactor npm scripts order for readability
- Remove unnecessary configs and libs
- Remove example image snapshots

Author: jhildenbiddle

.eslintignore

@@ -1,10 +1,9 @@
 .git
-packages/docsify-server-renderer/build.js
-node_modules
+**/*.md
 build
-server.js
+docs
 lib
+node_modules
+packages/docsify-server-renderer/build.js
+server.js
 themes
-build
-docs/
-**/*.md

.eslintrc.js

@@ -1,24 +1,28 @@
+const prettierConfig = require('./.prettierrc');
+
 module.exports = {
   root: true,
-  parser: 'babel-eslint',
+  extends: [
+    'eslint:recommended',
+    'plugin:import/recommended',
+    'plugin:prettier/recommended', // Must be last
+  ],
+  parser: '@babel/eslint-parser',
   parserOptions: {
     sourceType: 'module',
     ecmaVersion: 2019,
   },
+  plugins: ['prettier', 'import'],
   env: {
     browser: true,
-    node: true,
     es6: true,
+    node: true,
   },
-  plugins: ['prettier', 'import'],
-  extends: ['eslint:recommended', 'plugin:import/recommended'],
   settings: {
     'import/ignore': ['node_modules', '.json$'],
   },
   rules: {
-    'prettier/prettier': ['error'],
     camelcase: ['warn'],
-    'no-useless-escape': ['warn'],
     curly: ['error', 'all'],
     'dot-notation': ['error'],
     eqeqeq: ['error'],
@@ -33,9 +37,16 @@ module.exports = {
     'no-proto': ['error'],
     'no-return-assign': ['error'],
     'no-self-compare': ['error'],
-    'no-shadow': ['warn'],
     'no-shadow-restricted-names': ['error'],
+    'no-shadow': [
+      'error',
+      {
+        allow: ['Events', 'Fetch', 'Lifecycle', 'Render', 'Router'],
+      },
+    ],
+    'no-unused-vars': ['error', { args: 'none' }],
     'no-useless-call': ['error'],
+    'no-useless-escape': ['warn'],
     'no-var': ['error'],
     'no-void': ['error'],
     'no-with': ['error'],
@@ -46,18 +57,21 @@ module.exports = {
 
     // Import rules
     // Search way how integrate with `lerna`
-    'import/no-unresolved': 'off',
     'import/imports-first': ['error'],
     'import/newline-after-import': ['error'],
     'import/no-duplicates': ['error'],
     'import/no-mutable-exports': ['error'],
-    'import/no-named-as-default': ['error'],
     'import/no-named-as-default-member': ['error'],
+    'import/no-named-as-default': ['error'],
+    'import/no-unresolved': 'off',
     'import/order': ['warn'],
+
+    // Prettier (Must be last)
+    'prettier/prettier': ['warn', prettierConfig],
   },
   globals: {
-    Docsify: 'writable',
     $docsify: 'writable',
+    Docsify: 'writable',
     dom: 'writable',
   },
 };