Switch bundler to tsdown

.gitignore

@@ -11,3 +11,5 @@
 node_modules
 oclif.manifest.json
 *.tgz
+tsconfig.tsbuildinfo
+/test/fixtures/**/dist

README.md

@@ -12,7 +12,7 @@ A command-line interface (CLI) to help develop [swup](https://swup.js.org/) site
 
 - Validate your website in CI/CD
 - Create plugins and themes from a best-practice template
-- Bundle plugins and themes using microbundle
+- Bundle plugins and themes using tsdown
 
 ![terminal screenshot](https://github.com/swup/cli/assets/869813/0d59b849-0801-4043-a325-801ed2d2982d)
 
@@ -125,7 +125,7 @@ FLAGS
 DESCRIPTION
   Build package
 
-  Build package code for distribution using microbundle
+  Build package code for distribution using tsdown
 
 EXAMPLES
   $ swup package:build
@@ -171,7 +171,7 @@ FLAGS
 DESCRIPTION
   Develop package
 
-  Build package code for development using microbundle and watch for changes
+  Build package code for development using tsdown and watch for changes
 
 EXAMPLES
   $ swup package:dev

eslint.config.js

@@ -0,0 +1,33 @@
+import { defineConfig } from 'eslint/config';
+import eslint from '@eslint/js';
+import tseslint from 'typescript-eslint';
+import prettierRecommended from 'eslint-plugin-prettier/recommended';
+
+export default defineConfig(
+	{
+		ignores: ['dist/', 'node_modules/', 'test/', 'bin/', '**/*.cjs', '**/*.js']
+	},
+	eslint.configs.recommended,
+	tseslint.configs.recommended,
+	prettierRecommended,
+	{
+		files: ['src/**/*.ts'],
+		languageOptions: {
+			parserOptions: {
+				projectService: true,
+				tsconfigRootDir: import.meta.dirname
+			}
+		},
+		rules: {
+			'no-unused-vars': 'off',
+			'@typescript-eslint/no-unused-vars': [
+				'error',
+				{ vars: 'all', args: 'none', caughtErrors: 'none' }
+			],
+			'@typescript-eslint/no-explicit-any': 'off',
+			'@typescript-eslint/ban-ts-comment': ['error', { 'ts-ignore': 'allow-with-description' }],
+			// This CLI deliberately formats caught errors into human-readable messages.
+			'preserve-caught-error': 'off'
+		}
+	}
+);