test(middleware-flexible-checksums): retry reuses the computed checksum

packages/middleware-flexible-checksums/src/middleware-flexible-checksums.retry.integ.spec.ts

@@ -0,0 +1,54 @@
+import { S3 } from "@aws-sdk/client-s3";
+import { HttpResponse } from "@smithy/protocol-http";
+import { describe, expect, test as it } from "vitest";
+
+import { flexibleChecksumsMiddleware } from "./flexibleChecksumsMiddleware";
+
+describe("middleware-flexible-checksums.retry", () => {
+  it("retry reuses the checksum", async () => {
+    const maxAttempts = 3;
+    const client = new S3({
+      maxAttempts,
+      requestHandler: {
+        handle: async () => ({
+          response: new HttpResponse({
+            statusCode: 500, // Fake Trasient Error
+          }),
+        }),
+      },
+    });
+
+    let flexChecksCallCount = 0;
+    const flexChecksCallCountMiddleware = (next: any) => async (args: any) => {
+      console.log("after flexChecks");
+      flexChecksCallCount++;
+      return await next(args);
+    };
+    client.middlewareStack.addRelativeTo(flexChecksCallCountMiddleware, {
+      name: flexChecksCallCountMiddleware.name,
+      toMiddleware: flexibleChecksumsMiddleware.name,
+      relation: "after",
+      override: true,
+    });
+
+    client.middlewareStack.identifyOnResolve(true);
+
+    await client
+      .putObject({
+        Bucket: "b",
+        Key: "k",
+        Body: "hello",
+      })
+      .catch((err) => {
+        console.log({ err, flexChecksCallCount });
+        // Expected, since we're faking transient error which is retried.
+
+        // Validate that flexibleChecksumsMiddleware is called once.
+        expect(flexChecksCallCount).toEqual(1);
+        // Validate that retryMiddleware is called maxAttempts times.
+        expect(err.$metadata.attempts).toEqual(maxAttempts);
+      });
+
+    expect.assertions(2);
+  });
+});