fix(s3-request-presigner): not mutate client mw stack (#3751)

packages/s3-request-presigner/src/getSignedUrl.spec.ts

@@ -42,7 +42,12 @@ describe("getSignedUrl", () => {
       Bucket: "Bucket",
       Key: "Key",
     });
-    const signed = await getSignedUrl(client, command);
+    const presignPromise = getSignedUrl(client, command);
+    // do not mutate to the client or command
+    expect(client.middlewareStack.remove("presignInterceptMiddleware")).toBe(false);
+    expect(command.middlewareStack.remove("presignInterceptMiddleware")).toBe(false);
+
+    const signed = await presignPromise;
     expect(signed).toBe(mockPresigned);
     expect(mockPresign).toBeCalled();
     expect(mockV4Presign).not.toBeCalled();

packages/s3-request-presigner/src/getSignedUrl.ts

@@ -26,7 +26,6 @@ export const getSignedUrl = async <
       delete request.headers["amz-sdk-request"];
       // User agent header would leak sensitive information
       delete request.headers["x-amz-user-agent"];
-
       const presigned = await s3Presigner.presign(request, {
         ...options,
         signingRegion: options.signingRegion ?? context["signing_region"],
@@ -42,21 +41,18 @@ export const getSignedUrl = async <
       } as any;
     };
   const middlewareName = "presignInterceptMiddleware";
-  client.middlewareStack.addRelativeTo(presignInterceptMiddleware, {
+  const clientStack = client.middlewareStack.clone();
+  clientStack.addRelativeTo(presignInterceptMiddleware, {
     name: middlewareName,
     relation: "before",
     toMiddleware: "awsAuthMiddleware",
     override: true,
   });
 
-  let presigned: HttpRequest;
-  try {
-    const output = await client.send(command);
-    //@ts-ignore the output is faked, so it's not actually OutputType
-    presigned = output.presigned;
-  } finally {
-    client.middlewareStack.remove(middlewareName);
-  }
+  const handler = command.resolveMiddleware(clientStack, client.config, {});
+  const { output } = await handler({ input: command.input });
+  //@ts-ignore the output is faked, so it's not actually OutputType
+  const { presigned } = output;
 
   return formatUrl(presigned);
 };