Update to eslint 9

.eslintignore.root

@@ -4,9 +4,6 @@
 *.min.js
 **/changelog/
 
-# Storybook files
-**/@(storybook|stories)/**/*.js
-
 # Ignored by default, but we should check it
 !.github/
 !.prettierrc.js

.github/eslint.config.mjs

@@ -0,0 +1,11 @@
+import makeBaseConfig from 'jetpack-js-tools/eslintrc/base.mjs';
+
+export default [
+	...makeBaseConfig( import.meta.url, { envs: [ 'node' ] } ),
+	{
+		rules: {
+			'no-console': 'off',
+			'n/no-process-exit': 'off',
+		},
+	},
+];

.pnpmfile.cjs

@@ -55,6 +55,11 @@ function fixDeps( pkg ) {
 				pkg.peerDependencies[ dep ] = ver.replace( /^\^?/, '>=' );
 			}
 		}
+
+		// Doesn't really need these at all with eslint 9 and our config.
+		pkg.peerDependenciesMeta ??= {};
+		pkg.peerDependenciesMeta[ '@typescript-eslint/eslint-plugin' ] = { optional: true };
+		pkg.peerDependenciesMeta[ '@typescript-eslint/parser' ] = { optional: true };
 	}
 
 	// Unnecessarily explicit deps. I don't think we really even need @wordpress/babel-preset-default at all.

eslint.config.mjs

@@ -0,0 +1,3 @@
+import makeBaseConfig from 'jetpack-js-tools/eslintrc/base.mjs';
+
+export default [ ...makeBaseConfig( import.meta.url ) ];

package.json

@@ -17,8 +17,8 @@
 		"cli-setup": "pnpm install && jetpack cli link",
 		"cli-unlink": "jetpack cli unlink",
 		"lint": "pnpm run lint-file .",
-		"lint-changed": "eslint-changed --ext .js,.jsx,.cjs,.mjs,.ts,.tsx,.svelte --git",
-		"lint-file": "eslint --ext .js,.jsx,.cjs,.mjs,.ts,.tsx,.svelte",
+		"lint-changed": "eslint-changed --ext .js,.jsx,.cjs,.mjs,.ts,.tsx,.svelte --eslint-options flags='[\"unstable_config_lookup_from_file\"]' --git",
+		"lint-file": "eslint --flag unstable_config_lookup_from_file",
 		"lint-required": "ESLINT_IGNORE_REQUIRED=1 pnpm run lint --max-warnings=0",
 		"php:autofix": "composer phpcs:fix",
 		"php:compatibility": "composer phpcs:compatibility",
@@ -28,7 +28,7 @@
 		"version-packages": "bash ./tools/version-packages.sh"
 	},
 	"devDependencies": {
-		"eslint": "8.57.1",
+		"eslint": "9.16.0",
 		"husky": "8.0.3",
 		"jetpack-cli": "workspace:*",
 		"jetpack-js-tools": "workspace:*"