watch utils folder and build it when updated

scripts/buildUtils.js

@@ -121,5 +121,7 @@ const createESMRawBuild = async () => {
   fs.writeFileSync("meta-raw-prod.json", JSON.stringify(rawProd.metafile));
 };
 
+console.info("BUILDING UTILS STARTED");
 createESMRawBuild();
 createESMBrowserBuild();
+console.info("BUILDING UTILS COMPLETE");

scripts/watchUtils.js

@@ -0,0 +1,16 @@
+const chokidar = require("chokidar");
+const path = require("path");
+const { execSync } = require("child_process");
+
+const BASE_PATH = `${path.resolve(`${__dirname}/..`)}`;
+const utilsDir = `${BASE_PATH}/packages/utils/src`;
+// One-liner for current directory
+chokidar.watch(utilsDir).on("change", (event) => {
+  console.info("Watching", event);
+  try {
+    execSync(`yarn workspace @excalidraw/utils run build:src`);
+  } catch (err) {
+    console.error("Error when building workspace", err);
+  }
+  console.info("BUILD DONE");
+});