From 473f94957f2912173fbbcdece52c23e78d960668 Mon Sep 17 00:00:00 2001
From: Trivikram Kamat <16024985+trivikr@users.noreply.github.com>
Date: Tue, 14 Jan 2025 21:42:45 -0800
Subject: [PATCH] fix(crc64-nvme-crt): return checksum for empty string if
 called without data (#6798)

---
 packages/crc64-nvme-crt/src/CrtCrc64Nvme.spec.ts |  5 +++--
 packages/crc64-nvme-crt/src/CrtCrc64Nvme.ts      | 13 +++++--------
 2 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/packages/crc64-nvme-crt/src/CrtCrc64Nvme.spec.ts b/packages/crc64-nvme-crt/src/CrtCrc64Nvme.spec.ts
index 6c71ae9ca944..90db0ae5430c 100644
--- a/packages/crc64-nvme-crt/src/CrtCrc64Nvme.spec.ts
+++ b/packages/crc64-nvme-crt/src/CrtCrc64Nvme.spec.ts
@@ -4,9 +4,10 @@ import { describe, expect, it } from "vitest";
 import { CrtCrc64Nvme } from "./CrtCrc64Nvme";
 
 describe(CrtCrc64Nvme.name, () => {
-  it("should throw an error if digest is called before update", async () => {
+  it("should return checksum for empty string if digest is called before update", async () => {
     const crc64 = new CrtCrc64Nvme();
-    await expect(crc64.digest()).rejects.toThrowError("No data provided to checksum");
+    const digest = await crc64.digest();
+    expect(toBase64(digest)).toEqual("AAAAAAAAAAA=");
   });
 
   it.each([
diff --git a/packages/crc64-nvme-crt/src/CrtCrc64Nvme.ts b/packages/crc64-nvme-crt/src/CrtCrc64Nvme.ts
index 3f8be18f148f..0bcff3ccc3cf 100644
--- a/packages/crc64-nvme-crt/src/CrtCrc64Nvme.ts
+++ b/packages/crc64-nvme-crt/src/CrtCrc64Nvme.ts
@@ -3,20 +3,17 @@ import { Checksum } from "@smithy/types";
 import { toUint8Array } from "@smithy/util-utf8";
 
 export class CrtCrc64Nvme implements Checksum {
-  private previous: DataView | undefined;
+  private checksum: DataView = new DataView(new ArrayBuffer(8));
 
-  update(chunk: Uint8Array) {
-    this.previous = checksums.crc64nvme(chunk, this.previous);
+  update(data: Uint8Array) {
+    this.checksum = checksums.crc64nvme(data, this.checksum);
   }
 
   async digest() {
-    if (!this.previous) {
-      throw new Error("No data provided to checksum");
-    }
-    return toUint8Array(this.previous);
+    return toUint8Array(this.checksum);
   }
 
   reset() {
-    this.previous = undefined;
+    this.checksum = new DataView(new ArrayBuffer(8));
   }
 }