Reject upload when status code is faulty

scripts/Utils/uploadWithProgress.ts

@@ -0,0 +1,29 @@
+export function uploadWithProgress(url, options: RequestInit, onProgress: ((ev: ProgressEvent) => any) | null): Promise<string> {
+	return new Promise((resolve, reject) => {
+		let xhr = new XMLHttpRequest()
+
+		xhr.onload = () => {
+			if(xhr.status >= 400) {
+				return reject(xhr.responseText)
+			}
+
+			resolve(xhr.responseText)
+		}
+		xhr.onerror = reject
+
+		if(onProgress && xhr.upload) {
+			xhr.upload.onprogress = onProgress
+			xhr.upload.onerror = reject
+		} else {
+			console.error("Could not attach progress event listener")
+		}
+
+		xhr.open(options.method || "GET", url, true)
+
+		for(let k in options.headers || {}) {
+			xhr.setRequestHeader(k, options.headers[k])
+		}
+
+		xhr.send(options.body)
+	})
+}