feat!: improve esm rules (#270)

Author: simenandre

README.md

@@ -45,6 +45,7 @@ These are the available configs:
 - `@bjerk/eslint-config/base`
 - `@bjerk/eslint-config/import`
 - `@bjerk/eslint-config/typescript`
+- `@bjerk/eslint-config/esm`
 
 **Note**: The main `@bjerk/eslint-config` config includes all the others, but
 also `prettier` (and `eslint-config-prettier`).

esm.js

@@ -0,0 +1,33 @@
+require('@rushstack/eslint-patch/modern-module-resolution');
+
+/**
+ * @type {import('eslint').Linter.Config}
+ **/
+const eslintConfigESM = {
+  plugins: ['unicorn', 'import'],
+  rules: {
+    /**
+     * Prefer using ESM over legacy CommonJS modules
+     * @see https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-module.md
+     */
+    'unicorn/prefer-module': 'error',
+
+    /**
+     * Prefer using the `node:` protocol when importing Node.js builtin modules
+     * @see https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-node-protocol.md
+     */
+    'unicorn/prefer-node-protocol': 'error',
+
+    /**
+     * Prefer top-level await over top-level promises and async function calls
+     * @see https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-top-level-await.md
+     */
+    'unicorn/prefer-top-level-await': 'error',
+
+    'import/extensions': ['error', 'always', { ignorePackages: true }],
+    'import/no-commonjs': 'error',
+  },
+};
+
+// eslint-disable-next-line no-undef
+module.exports = eslintConfigESM;

import.js

@@ -1,5 +1,8 @@
 require('@rushstack/eslint-patch/modern-module-resolution');
 
+/**
+ * @type {import('eslint').Linter.Config}
+ **/
 const eslintConfigImport = {
   plugins: ['import'],
   rules: {
@@ -22,6 +25,12 @@ const eslintConfigImport = {
         ignoreDeclarationSort: true,
       },
     ],
+    'import/no-useless-path-segments': [
+      'error',
+      {
+        noUselessIndex: true,
+      },
+    ],
   },
   overrides: [
     {

index.js

@@ -1,7 +1,7 @@
 require('@rushstack/eslint-patch/modern-module-resolution');
 
 const eslintConfig = {
-  extends: ['./base', './typescript', './import', 'prettier'],
+  extends: ['./base', './typescript', './import', './esm', 'prettier'],
 };
 
 // eslint-disable-next-line no-undef