watch mode for build (#64)

Author: alanorozco

bin/build.mjs

@@ -1,5 +1,8 @@
 import esbuild from 'esbuild';
 import {readFile} from 'fs/promises';
+import minimist from 'minimist';
+
+const argv = minimist(process.argv.slice(2));
 
 const readJson = async (path) =>
   JSON.parse(await readFile(new URL(path, import.meta.url)));
@@ -46,6 +49,7 @@ async function build() {
         platform: 'node',
         logLevel: 'info',
         plugins: [preactCompatPlugin],
+        watch: argv.watch,
         external,
         outdir,
         ...options,

package.json

@@ -37,11 +37,13 @@
     "babel-loader": "8.2.3",
     "core-js": "3.21.0",
     "esbuild": "0.14.21",
+    "minimist": "1.2.5",
     "react": "17.0.2"
   },
   "scripts": {
     "dev": "tsc --watch --preserveWatchOutput",
     "build": "node bin/build.mjs",
+    "watch": "npm run build -- --watch",
     "test": "echo 'No tests' && exit 0",
     "clean": "rm -r esm dist",
     "prepublishOnly": "npm run build",