Get upload time for files from backblaze and provide timestamp for status data

dist/services/CloudflareService.d.ts

@@ -4,7 +4,10 @@ declare class CloudflareService {
     private _defaultBucket;
     private _statusesService;
     constructor(cdnUrl: string, defaultBucket: string);
-    fetchFile(fileName: string, bucket?: string): Promise<unknown>;
+    fetchFile<T>(fileName: string, bucket?: string): Promise<{
+        data: T;
+        uploadTime: number;
+    }>;
     fetchStatusData(statusFileName: string): Promise<StatusData>;
     readStatuses(statusId: string): Promise<Array<StatusData>>;
     getMerkleTree(fileName: string): Promise<Array<string>>;

dist/types.d.ts

@@ -28,6 +28,7 @@ export interface StatusData {
     statusClassName?: string;
     batchId: string;
     transactionHash: string;
+    timestamp: number;
 }
 export interface BatchVerificationDetails {
     statusPosition: number;

src/services/CloudflareService.ts

@@ -30,23 +30,29 @@ class CloudflareService {
     this._statusesService = new StatusesService();
   }
 
-  async fetchFile(
+  async fetchFile<T>(
     fileName: string,
     bucket = this._defaultBucket
-  ): Promise<unknown> {
+  ): Promise<{ data: T; uploadTime: number }> {
     // v?= is a dirty fix to prevent caching of the CORS error response in case file is missing.
     // Because of browser caching CORS error in case of missing file, it's not possible to retrieve it when it's being uploaded.
     // Dig into https://www.backblaze.com/b2/docs/cors_rules.html and fix
-    const { data } = await axios(
-      `${this._cdnUrl}/file/${bucket}/${fileName}?v=${Math.random()}`
-    );
-    return data;
+    const response = await axios(`${this._cdnUrl}/file/${bucket}/${fileName}`);
+
+    const data = response.data as T;
+
+    const uploadTime = response.headers["x-bz-upload-timestamp"]
+      ? parseInt(response.headers["x-bz-upload-timestamp"])
+      : -1;
+
+    return { data, uploadTime };
   }
 
   async fetchStatusData(statusFileName: string): Promise<StatusData> {
-    const rawStatusData = (await this.fetchFile(
-      statusFileName
-    )) as RawStatusData;
+    const {
+      data: rawStatusData,
+      uploadTime,
+    } = await this.fetchFile<RawStatusData>(statusFileName);
     let decodedResult;
     try {
       decodedResult = this._statusesService.decodeStatusObject(
@@ -62,6 +68,7 @@ class CloudflareService {
       transactionHash: rawStatusData.TransactionID,
       statusRaw: rawStatusData.Status,
       statusClassName: decodedResult.className,
+      timestamp: uploadTime,
     };
   }
 
@@ -91,9 +98,9 @@ class CloudflareService {
   }
 
   async getMerkleTree(fileName: string): Promise<Array<string>> {
-    const merkleTreeFileContents = (await this.fetchFile(
+    const { data: merkleTreeFileContents } = await this.fetchFile<string[]>(
       fileName
-    )) as Array<string>;
+    );
 
     const statusesData: Array<StatusData> = await Promise.all(
       merkleTreeFileContents.map((statusFileName) => {

src/services/QrCodeDataService.ts

@@ -230,9 +230,11 @@ const withServices = (
 
       const base64SHA256 = await cryptoService.SHA256(base64);
 
-      const backblazeDataPart = (await cloudFlareServiceInstance.fetchFile(
+      const {
+        data: backblazeDataPart,
+      } = await cloudFlareServiceInstance.fetchFile<BackblazeDataPartRaw>(
         `qrcode-${arrayBufferToHex(base64SHA256)}`
-      )) as BackblazeDataPartRaw;
+      );
 
       const assembledData = assembleQrCodeData(
         base64ToArrayBuffer(qrCodeDataPart.data),

src/services/VerificationService/VerificationService.ts

@@ -196,9 +196,9 @@ class VerificationService extends EventEmitter {
       if (verificationMethod === VERIFICATION_METHOD_MERKLE_TREE) {
         batchItems = await this._cloudflareService.getMerkleTree(batchFilename);
       } else if (verificationMethod === VERIFICATION_METHOD_SHA256_BATCH) {
-        batchItems = (await this._cloudflareService.fetchFile(
-          batchFilename
-        )) as string[];
+        ({ data: batchItems } = await this._cloudflareService.fetchFile<
+          string[]
+        >(batchFilename));
       }
     } catch (e) {
       this.catchVerificationError(

src/types.ts

@@ -32,6 +32,7 @@ export interface StatusData {
   statusClassName?: string;
   batchId: string;
   transactionHash: string;
+  timestamp: number;
 }
 
 export interface BatchVerificationDetails {