Fix for ESM workers

papaparse.js

@@ -1736,7 +1736,7 @@
 			return false;
 
 		var workerUrl = SCRIPT_URL;
-		var w = new global.Worker(workerUrl, { name: PAPA_WORKER_NAME });
+		var w = new global.Worker(workerUrl, { name: PAPA_WORKER_NAME, type: true ? undefined : 'module' });
 		w.onmessage = mainThreadReceivedMessage;
 		w.id = workerIdCounter++;
 		workers[w.id] = w;

papaparse.mjs

@@ -37,9 +37,7 @@ export var NODE_STREAM_INPUT = 1;
 
 // Configurable chunk sizes for local and remote files, respectively
 export var LocalChunkSize = 1024 * 1024 * 10;	// 10 MB
-// eslint-disable-next-line prefer-const
 export var RemoteChunkSize = 1024 * 1024 * 5;	// 5 MB
-// eslint-disable-next-line prefer-const
 export var DefaultDelimiter = ',';  			// Used if not specified and detection fails
 
 // Exposed for testing and development only
@@ -1732,7 +1730,7 @@ function newWorker()
 		return false;
 
 	var workerUrl = SCRIPT_URL;
-	var w = new global.Worker(workerUrl, { name: PAPA_WORKER_NAME });
+	var w = new global.Worker(workerUrl, { name: PAPA_WORKER_NAME, type: import.meta.papaIsUMD ? undefined : 'module' });
 	w.onmessage = mainThreadReceivedMessage;
 	w.id = workerIdCounter++;
 	workers[w.id] = w;

rollup.config.mjs

@@ -18,9 +18,14 @@ export default {
 	plugins: [
 		{
 			resolveImportMeta(prop, { format }) {
-				if (prop === 'url' && format === 'umd') {
+				if (format === 'umd') {
+					if (prop === 'url') {
 						return 'global && global.document && global.document.currentScript && global.document.currentScript.src';
 					}
+					if (prop === 'papaIsUMD') {
+						return 'true';
+					}
+				}
 			}
 		}
 	]