fix: allowed extensions

internals.js

@@ -1,4 +1,6 @@
 const { generateIslands, getManifest } = require('./lib/plugin')
+const { ALLOWED_EXTENSIONS } = require('./lib/constants')
 
 exports.generateIslands = generateIslands
 exports.getManifest = getManifest
+exports.ALLOWED_EXTENSIONS = ALLOWED_EXTENSIONS

lib/constants.js

@@ -0,0 +1 @@
+exports.ALLOWED_EXTENSIONS = ['jsx', 'js', 'ts', 'tsx']

rollup.js

@@ -7,6 +7,8 @@ const { nodeResolve } = require('@rollup/plugin-node-resolve')
 const jsx = require('acorn-jsx')
 const { babel } = require('@rollup/plugin-babel')
 const { resolveTsConfig } = require('./lib/typescript')
+const path = require('path')
+const { ALLOWED_EXTENSIONS } = require('./lib/constants')
 
 exports = module.exports = rollupPlugin
 
@@ -30,6 +32,7 @@ function rollupPlugin(options = defaultOptions) {
   return {
     name: 'preact-island-plugin',
     async transform(_, id) {
+      if (!ALLOWED_EXTENSIONS.includes(path.extname(id))) return
       if (id.includes('virtual:')) return
       // ignore files that don't exist
       if (!existsSync(id)) return