Migrate to ESLint 9 w/ flat config

Closes js-cookie#856

Author: carhartl

.eslintignore

@@ -0,0 +1,30 @@
+import globals from 'globals'
+import js from '@eslint/js'
+
+const languageOptions = {
+  globals: {
+    ...globals.browser
+  }
+}
+export default [
+  {
+    ignores: ['dist/*']
+  },
+  {
+    ...js.configs.recommended,
+    files: ['**/*.js'],
+    ignores: ['examples/**/src/*.js'],
+    languageOptions: {
+      ...languageOptions,
+      sourceType: 'commonjs'
+    }
+  },
+  {
+    ...js.configs.recommended,
+    files: ['**/*.mjs'],
+    languageOptions: {
+      ...languageOptions,
+      ecmaVersion: 2021
+    }
+  }
+]

.eslintrc.json

@@ -30,8 +30,8 @@
     "test": "grunt test",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
-    "lint": "eslint --ext .js,.mjs --fix .",
-    "lint:check": "eslint --ext .js,.mjs .",
+    "lint": "eslint --fix .",
+    "lint:check": "eslint .",
     "dist": "rm -rf dist/* && rollup -c",
     "release": "release-it"
   },
@@ -48,7 +48,7 @@
   "devDependencies": {
     "@rollup/plugin-terser": "^0.4.4",
     "browserstack-runner": "github:browserstack/browserstack-runner#1e85e559951bdf97ffe2a7c744ee67ca83589fde",
-    "eslint": "^8.43.0",
+    "eslint": "^9.0.0",
     "eslint-config-prettier": "^9.0.0",
     "eslint-plugin-html": "^8.0.0",
     "eslint-plugin-markdown": "^4.0.1",

eslint.config.mjs

@@ -65,7 +65,7 @@ function init(converter, defaultAttributes) {
         if (name === found) {
           break
         }
-      } catch (e) {
+      } catch {
         // Do nothing...
       }
     }

package.json

@@ -251,7 +251,6 @@ QUnit.test('String primitive', function (assert) {
 })
 
 QUnit.test('String object', function (assert) {
-  // eslint-disable-next-line no-new-wrappers
   Cookies.set('c', new String('v'))
   assert.strictEqual(Cookies.get('c'), 'v', 'should write value')
 })

src/api.mjs

@@ -53,7 +53,7 @@
                 )
                 callback(result.value, iframeDocument.cookie)
                 done()
-              } catch (e) {
+              } catch {
                 // Do nothing...
               }
             })