Metadata support added for DownloadTask. Android & Ios

lib/downloadTask.js

@@ -10,6 +10,7 @@ export default class DownloadTask {
     percent = 0
     bytesWritten = 0
     totalBytes = 0
+    metadata = {}
 
     constructor (taskInfo, originalTask) {
       if (typeof taskInfo === 'string') {
@@ -19,6 +20,10 @@ export default class DownloadTask {
         this.percent = taskInfo.percent
         this.bytesWritten = taskInfo.bytesWritten
         this.totalBytes = taskInfo.totalBytes
+
+        if (this.#parseable(taskInfo.metadata)) {
+          this.metadata = JSON.parse(taskInfo.metadata);
+        }
       }
 
       if (originalTask) {
@@ -93,4 +98,13 @@ export default class DownloadTask {
       this.state = 'STOPPED'
       RNBackgroundDownloader.stopTask(this.id)
     }
+
+    #parseable = (element) => {
+      try {
+        JSON.parse(element);
+        return true;
+      } catch (err) {
+        return false;
+      }
+    }
 }