feat: add optional onError callback options key

index.d.ts

@@ -89,6 +89,12 @@
 		*/
 		readonly onCompleted?: (file: File) => void;
 
+		/**
+		Optional callback that receives an error title and an error message. It is called every time when download state is "interrupted".
+		If callback is not provided error will be shown in Electron error dialog.
+		*/
+		readonly onError?: (errorTitle: string, errorMessage: string) => void;
+
 		/**
 		Reveal the downloaded file in the system file manager, and if possible, select the file.
 
@@ -159,7 +165,7 @@
 	})();
 	```
 	*/
 	(options?: electronDl.Options): void;
 
 	/**
 	This can be useful if you need download functionality in a reusable module.

index.js

@@ -152,7 +152,7 @@
 				if (typeof options.onCancel === 'function') {
 					options.onCancel(item);
 				}
 				callback(new CancelError());
 			} else if (state === 'interrupted') {
 				const message = pupa(errorMessage, {filename: path.basename(filePath)});
 				callback(new Error(message));
@@ -195,7 +195,11 @@
 		registerListener(session, options, (error, _) => {
 			if (error && !(error instanceof CancelError)) {
 				const errorTitle = options.errorTitle || 'Download Error';
-				dialog.showErrorBox(errorTitle, error.message);
+				if ('onError' in options && typeof options.onError === 'function') {
+					options.onError(errorTitle, error.message);
+				} else {
+					dialog.showErrorBox(errorTitle, error.message);
+				}
 			}
 		});
 	});

readme.md

@@ -191,6 +191,14 @@ Optional callback that receives an object with information about an item that ha
 }
 ```
 
+#### onError
+
+Type: `Function`
+
+Optional callback that receives an error title and an error message. It is called every time when download state is "interrupted".
+If callback is not provided error will be shown in Electron error dialog.
+(*is applied only in default exported function, not for usage inside 'download' function)
+
 #### openFolderWhenDone
 
 Type: `boolean`\