chore: migrate to mocha and eslint 9

Migrates from Jest to mocha and node's own `assert` library.

Also updates ESLint to 9.x and bumps TSESLint to do the same.

.c8rc.json

@@ -0,0 +1,5 @@
+{
+    "reporter": ["lcov"],
+    "include": ["packages/*/lib/**/*.ts"],
+    "exclude": []
+}

.github/workflows/nodejs-test.yml

@@ -57,12 +57,12 @@ jobs:
             - run: npm ci
             - run: npm run build --if-present
 
-            - name: Run Jest
+            - name: Run unit tests
               run: npm run unit-tests
               if: matrix.node != env.NODE_COV
 
-            - name: Run Jest with coverage
-              run: npm run unit-tests -- --coverage
+            - name: Run unit tests with coverage
+              run: npm run unit-tests-coverage
               if: matrix.node == env.NODE_COV
 
             - name: Run Coveralls

.mocharc.json

@@ -0,0 +1,7 @@
+{
+    "require": "ts-node/register",
+    "loader": "ts-node/esm",
+    "extensions": ["ts"],
+    "spec": ["**/*.test.ts"],
+    "watch-files": ["packages/*/lib"]
+}

bench/memory/sax-parser.js

@@ -4,6 +4,8 @@ import memwatch from '@airbnb/node-memwatch';
 import { SAXParser } from '../../packages/parse5-sax-parser/dist/index.js';
 import { finished } from 'parse5-test-utils/dist/common.js';
 
+/* eslint-disable no-console */
+
 const heapDiffMeasurement = new memwatch.HeapDiff();
 
 let maxMemUsage = 0;

bench/perf/index.js

@@ -7,6 +7,8 @@ import * as parse5 from '../../packages/parse5/dist/index.js';
 import { ParserStream as parse5Stream } from '../../packages/parse5-parser-stream/dist/index.js';
 import * as parse5Upstream from 'parse5';
 
+/* eslint-disable no-console */
+
 const hugePagePath = new URL('../../test/data/huge-page/huge-page.html', import.meta.url);
 const treeConstructionPath = new URL('../../test/data/html5lib-tests/tree-construction', import.meta.url);
 const saxPath = new URL('../../test/data/sax/', import.meta.url);

eslint.config.js

@@ -0,0 +1,77 @@
+import eslintjs from '@eslint/js';
+import eslintConfigPrettier from 'eslint-config-prettier';
+import { configs as tseslintConfigs } from 'typescript-eslint';
+import globals from 'globals';
+
+const { configs: eslintConfigs } = eslintjs;
+
+const sourceFiles = ['bench/**/*.js', 'scripts/**/*.ts', 'packages/*/lib/**/*.ts'];
+const testFiles = ['test/**/*.{ts,js}'];
+const ignoreFiles = [
+    'test/data/html5lib-tests',
+    'test/data/html5lib-tests-fork',
+    'packages/*/dist/',
+    'test/dist/',
+    'docs/build/',
+];
+const allFiles = [...sourceFiles, ...testFiles];
+
+export default [
+    {
+        files: allFiles,
+    },
+    {
+        ignores: ignoreFiles,
+    },
+    {
+        languageOptions: {
+            globals: {
+                ...globals.nodeBuiltin,
+                ...globals.es2019,
+            },
+        },
+    },
+    eslintConfigs.recommended,
+    ...tseslintConfigs.recommended,
+    {
+        rules: {
+            'no-console': 'error',
+            curly: ['error', 'all'],
+            'prefer-arrow-callback': 'error',
+            'one-var': ['error', 'never'],
+            'no-var': 'error',
+            'prefer-const': 'error',
+            'object-shorthand': 'error',
+            'prefer-destructuring': [
+                'error',
+                {
+                    object: true,
+                    array: false,
+                },
+            ],
+            'prefer-template': 'error',
+            'arrow-body-style': ['error', 'as-needed'],
+        },
+    },
+    {
+        files: testFiles,
+        languageOptions: {
+            globals: {
+                ...globals.mocha,
+            },
+        },
+    },
+    {
+        files: ['**/*.ts'],
+        rules: {
+            '@typescript-eslint/no-unsafe-declaration-merging': 'off',
+            '@typescript-eslint/no-non-null-assertion': 'warn',
+            '@typescript-eslint/no-explicit-any': 'warn',
+            '@typescript-eslint/explicit-function-return-type': 'error',
+            '@typescript-eslint/consistent-type-imports': 'error',
+
+            '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
+        },
+    },
+    eslintConfigPrettier,
+];