Use ESLint v9.

- Update dependencies.
  - `eslint@9` and related packages.
- Rework all configs to new eslint style.

Author: davidlehn

.editorconfig

@@ -0,0 +1,13 @@
+# https://editorconfig.org
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+
+[*.{cjs,js,json,jsonld,mjs,yaml,yml}]
+indent_style = space
+indent_size = 2

.eslintrc.js

@@ -1,4 +1,4 @@
-name: Lint CI
+name: Main CI
 
 on: [push]
 
@@ -8,11 +8,11 @@ jobs:
     timeout-minutes: 10
     strategy:
       matrix:
-        node-version: [14.x]
+        node-version: [24.x]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
+      uses: actions/setup-node@v4
       with:
         node-version: ${{ matrix.node-version }}
     - run: npm install

.github/workflows/main.yml renamed to .github/workflows/main.yaml

@@ -1,5 +1,37 @@
 # eslint-config-digitalbazaar ChangeLog
 
+### 6.0.0 - 2025-08-xx
+
+### Changed
+- **BREAKING**: Update to `eslint@9`.
+  - Please see the migration notes below.
+  - Comments and suggestions welcome for how best to adapt to the rules that
+    were changed, added, or removed between v8 and v9.
+  - The way configuration is done change significantly. Suggestions welcome on
+    how best to adapt to the new style.
+
+### Migration
+- ESLint v9 is a major breaking change and will require manual updates.
+- ESLint has a migration guide:
+  - https://eslint.org/docs/latest/use/configure/migration-guide
+- A few major notes:
+  - The configuration file changes from multiple `.eslintrc.cjs` or similar to
+    a single top level `eslint.config.js`.
+  - Invocation is now `eslint` without options.
+  - Style rules were deprecated and moved to the stylistic project.
+  - The Digital Bazaar rules are mostly the same as before with updates to
+    `@stylistic/RULENAME` as needed.
+  - Note the common `max-len` is now `@stylistic/max-len`.
+  - Unused rules are now flagged which should help with migration to new rules,
+    or elimination of unused rules.
+  - Quasar has not yet updated support for v9. Until that is updated, stay with
+    v8, or update to v9 and drop Quasar linting and only use Vue linting.
+- Major types of rules are grouped together.
+- The groups can be composed together as needed.
+- There are opinionated configs that compose a number of rules and apply to
+  many common Digital Bazaar repositories.
+- See the [README](./README.md) for notes and usage examples.
+
 ### 5.2.0 - 2024-05-02
 
 ### Changed

CHANGELOG.md

@@ -10,7 +10,6 @@ There are 6 rule sets:
 5. `eslint-config-digitalbazaar/vue`: Rules for Vue 2 projects and browser only.
 6. `eslint-config-digitalbazaar/vue3`: Rules for Vue 3 projects and browser only.
 
-
 ## Installation
 
 If you do not have eslint installed:
@@ -25,17 +24,17 @@ npx eslint --init
 ```
 or rename a template from the templates dir
 ```
-cp node_modules/eslint-config-digitalbazaar/templates/node.js ./.eslintrc.cjs
+cp node_modules/eslint-config-digitalbazaar/templates/node.js ./eslint.config.js
 ```
 
 ## Usage
 
 All rules can be accessed via the shorthand `digitalbazaar`
 or using the full module name `eslint-config-digitalbazaar`.
 
-Eslint's documentation on [shareable configs](https://eslint.org/docs/developer-guide/shareable-configs) can be found here.
+ESLint's documentation on [shareable configs](https://eslint.org/docs/developer-guide/shareable-configs) can be found here.
 
-Example .eslintrc.cjs root setup:
+Example `eslint.config.js` root setup:
 ```js
 module.exports = {
   root: true,
@@ -52,7 +51,7 @@ To use the import rules you need to install [`eslint-plugin-import`](https://git
 npm i -D eslint-plugin-import
 ```
 
-Example .eslintrc.cjs import setup:
+Example `eslint.config.js` import setup:
 ```js
 module.exports = {
   extends: ['digitalbazaar/import']
@@ -66,7 +65,7 @@ To use the JSDoc rules you will need to install [`eslint-plugin-jsdoc`](https://
 npm i -D eslint-plugin-jsdoc
 ```
 
-Example .eslintrc.cjs JSDoc setup:
+Example `eslint.config.js` JSDoc setup:
 ```js
 module.exports = {
   // only the JSDoc rules and any rules in parent dirs
@@ -81,7 +80,7 @@ To use ES module code rather than CommonJS, you will need to install [`eslint-pl
 npm i -D eslint-plugin-unicorn
 ```
 
-Example .eslintrc.cjs ESM setup:
+Example `eslint.config.js` ESM setup:
 ```js
 module.exports = {
   // only the module rules and any rules in parent dirs
@@ -96,7 +95,7 @@ To use the Vue 2 rules you will need to install [`eslint-plugin-vue`](https://es
 npm i -D eslint-plugin-vue
 ```
 
-Example .eslintrc.cjs Vue setup:
+Example `eslint.config.js` Vue setup:
 ```js
 module.exports = {
   // only the vue rules and any rules in parent dirs
@@ -114,7 +113,7 @@ To use the Vue 3 rules you will need to install [`eslint-plugin-vue`](https://es
 npm i -D eslint-plugin-vue
 ```
 
-Example .eslintrc.cjs Vue setup:
+Example `eslint.config.js` Vue setup:
 ```js
 module.exports = {
   // only the vue3 rules and any rules in parent dirs

README.md

@@ -0,0 +1,19 @@
+import digitalbazaar from './index.js';
+import digitalbazaarImport from './import.js';
+import globals from 'globals';
+
+export default [
+  ...digitalbazaar,
+  {
+    files: ['**/*.js'],
+    languageOptions: {
+      globals: {
+        ...globals.node
+      }
+    },
+  },
+  {
+    ...digitalbazaarImport,
+    files: ['test/import/*.js']
+  }
+];

eslint.config.js

@@ -1,35 +1,37 @@
-module.exports = {
-  env: {
-    es2020: true
-  },
-  parserOptions: {
-    sourceType: 'module'
-  },
-  plugins: [
-    // https://github.com/import-js/eslint-plugin-import
-    'import'
-  ],
-  rules: {
-    // Verifies that all named imports are part of the set of named
-    // exports in the imported module.
-    'import/named': 'error',
-    // If a default import is requested, this rule will report if
-    // there is no default export in the imported module.
-    'import/default': 'error',
-    // throws if a namespace like `import * as all` is used and
-    // `all.foo` is not exported
-    'import/namespace': 'error',
-    // throws if a module imports itself
-    'import/no-self-import': 'error',
-    // Reports funny business with exports, like repeated exports
-    // of names or defaults.
-    'import/export': 'error',
-    // warns if an imported member if marked @deprecated
-    'import/no-deprecated': 'error',
-    // warns if a dep is not in the package.json
-    'import/no-extraneous-dependencies': 'error',
-    // disallows exporting members with let & var
-    // throw if you import something more than once in a file/module
-    'import/no-duplicates': 'error'
+import eslintPluginImport from 'eslint-plugin-import';
+
+export default [
+  {
+    languageOptions: {
+      ecmaVersion: 2020,
+      sourceType: 'module'
+    },
+    plugins: {
+      // https://github.com/import-js/eslint-plugin-import
+      import: eslintPluginImport
+    },
+    rules: {
+      // Verifies that all named imports are part of the set of named
+      // exports in the imported module.
+      'import/named': 'error',
+      // If a default import is requested, this rule will report if
+      // there is no default export in the imported module.
+      'import/default': 'error',
+      // throws if a namespace like `import * as all` is used and
+      // `all.foo` is not exported
+      'import/namespace': 'error',
+      // throws if a module imports itself
+      'import/no-self-import': 'error',
+      // Reports funny business with exports, like repeated exports
+      // of names or defaults.
+      'import/export': 'error',
+      // warns if an imported member if marked @deprecated
+      'import/no-deprecated': 'error',
+      // warns if a dep is not in the package.json
+      'import/no-extraneous-dependencies': 'error',
+      // disallows exporting members with let & var
+      // throw if you import something more than once in a file/module
+      'import/no-duplicates': 'error'
+    }
   }
-};
+];