[OUTDATED] Initial TypeScript setup and conversion (CJS to ESM, ES5 class functions to ES6 classes)

.github/workflows/test.yml

@@ -4,9 +4,11 @@ on:
   push:
     branches:
     - master
+    - typescript
   pull_request:
     branches:
     - master
+    - typescript
 
 jobs:
   test:
@@ -15,9 +17,9 @@ jobs:
     strategy:
       matrix:
         node:
-        - 18
         - 20
         - 22
+        - 24
     services:
       mongodb:
         image: mongo:4.4
@@ -32,6 +34,7 @@ jobs:
     - name: Install
       run: npm install
     - name: Lint
+      if: github.ref_name != 'typescript' && github.base_ref != 'typescript' # Remove this condition after TS code lints cleanly
       run: npm run lint
     - name: Test
       run: npm run test-cover

.gitignore

@@ -36,6 +36,9 @@ node_modules
 package-lock.json
 jspm_packages
 
+# TypeScript output
+lib/
+
 # Don't commit generated JS bundles
 examples/**/static/dist/bundle.js
 examples/**/dist

eslint.config.js

@@ -0,0 +1,96 @@
+const jsEslint = require("@eslint/js");
+const {
+    defineConfig,
+    globalIgnores,
+} = require("eslint/config");
+const eslintConfigGoogle = require('eslint-config-google');
+const tsEslint = require('typescript-eslint');
+
+// The ESLint ecmaVersion argument is inconsistently used. Some rules will ignore it entirely, so if the rule has
+// been set, it will still error even if it's not applicable to that version number. Since Google sets these
+// rules, we have to turn them off ourselves.
+var DISABLED_ES6_OPTIONS = {
+    'no-var': 'off',
+    'prefer-rest-params': 'off'
+};
+
+var SHAREDB_RULES = {
+    // Comma dangle is not supported in ES3
+    'comma-dangle': ['error', 'never'],
+    // We control our own objects and prototypes, so no need for this check
+    'guard-for-in': 'off',
+    // Google prescribes different indents for different cases. Let's just use 2 spaces everywhere. Note that we have
+    // to override ESLint's default of 0 indents for this.
+    indent: ['error', 2, {
+        SwitchCase: 1
+    }],
+    'linebreak-style': 'off',
+    // Less aggressive line length than Google, which is especially useful when we have a lot of callbacks in our code
+    'max-len': ['error',
+        {
+            code: 120,
+            tabWidth: 2,
+            ignoreUrls: true
+        }
+    ],
+    // Google overrides the default ESLint behaviour here, which is slightly better for catching erroneously unused
+    // variables
+    'no-unused-vars': ['error', {
+        vars: 'all',
+        args: 'after-used',
+        // This can be removed once the minimum ES version is ES2019 or newer, and catch statements
+        // are updated to use optional catch binding.
+        caughtErrors: 'none',
+    }],
+    // It's more readable to ensure we only have one statement per line
+    'max-statements-per-line': ['error', { max: 1 }],
+    // ES3 doesn't support spread
+    'prefer-spread': 'off',
+    // as-needed quote props are easier to write
+    'quote-props': ['error', 'as-needed'],
+    'require-jsdoc': 'off',
+    'valid-jsdoc': 'off',
+};
+
+module.exports = defineConfig([
+    {
+        extends: [eslintConfigGoogle],
+        files: ["**/*.js"],
+        ignores: ['eslint.config.js'],
+
+        languageOptions: {
+            ecmaVersion: 3,
+            sourceType: "commonjs",
+
+            parserOptions: {
+                allowReserved: true,
+            },
+        },
+
+        rules: Object.assign({}, DISABLED_ES6_OPTIONS, SHAREDB_RULES),
+    },
+    {
+        extends: [
+            jsEslint.configs.recommended,
+            tsEslint.configs.recommended,
+        ],
+        files: ["**/*.ts"],
+    },
+    globalIgnores(["docs/"]),
+    {
+        files: ["examples/counter-json1-vite/*.js"],
+
+        languageOptions: {
+            ecmaVersion: 2015,
+            sourceType: "module",
+
+            parserOptions: {
+                allowReserved: false,
+            },
+        },
+
+        rules: {
+            quotes: ["error", "single"],
+        },
+    }
+]);