Address dmichon-msft review comments

- Add clarifying comment on maxAttempts: 1 for uploads explaining why
  the parameter exists (shared between download with retries and upload
  without)
- Replace S3 download snapshot containing auth headers with explicit
  field assertions, avoiding credential-looking strings in snapshots
- Update inline snapshot for "unknown length" wording change

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: iclanton

rush-plugins/rush-amazon-s3-build-cache-plugin/src/test/AmazonS3Client.test.ts

@@ -716,7 +716,13 @@ describe(AmazonS3Client.name, () => {
         );
         expect(result).toBe(true);
         expect(spy).toHaveBeenCalledTimes(1);
-        expect(spy.mock.calls[0]).toMatchSnapshot();
+        const [url, options] = spy.mock.calls[0];
+        expect(url).toBe('http://localhost:9000/abc123');
+        expect(options.verb).toBe('GET');
+        expect(options.headers['x-amz-content-sha256']).toMatch(/^[0-9a-f]{64}$/);
+        expect(options.headers['x-amz-date']).toBe('20200418T123242Z');
+        // eslint-disable-next-line dot-notation
+        expect(options.headers['Authorization']).toContain('AWS4-HMAC-SHA256');
         expect(pipeline).toHaveBeenCalled();
         spy.mockRestore();
       });

rush-plugins/rush-amazon-s3-build-cache-plugin/src/test/__snapshots__/AmazonS3Client.test.ts.snap

@@ -549,17 +549,3 @@ exports[`AmazonS3Client Rejects invalid S3 endpoint values 10`] = `"Invalid S3 e
 
 exports[`AmazonS3Client Rejects invalid S3 endpoint values 11`] = `"Invalid S3 endpoint. Some part of the hostname contains invalid characters or is too long"`;
 
-exports[`AmazonS3Client File-based requests Downloading an object to file Can download an object to file 1`] = `
-Array [
-  "http://localhost:9000/abc123",
-  Object {
-    "headers": Object {
-      "Authorization": "AWS4-HMAC-SHA256 Credential=accessKeyId/20200418/us-east-1/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256;x-amz-date,Signature=194608e9e7ba6d8aa4a019b3b6fd237e6b09ef1f45ff7fa60cbb81c1875538be",
-      "x-amz-content-sha256": "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
-      "x-amz-date": "20200418T123242Z",
-    },
-    "verb": "GET",
-  },
-]
-`;
-

rush-plugins/rush-http-build-cache-plugin/src/HttpBuildCacheProvider.ts

@@ -209,7 +209,9 @@ export class HttpBuildCacheProvider implements ICloudBuildCacheProvider {
         method: this._uploadMethod,
         body: entryStream,
         warningText: 'Could not write cache entry',
-        // Streaming uploads cannot be retried because the stream is consumed
+        // maxAttempts is 1 because the file read stream is consumed after the first attempt
+        // and cannot be replayed. Downloads use MAX_HTTP_CACHE_ATTEMPTS since each retry
+        // issues a fresh GET with no request body.
         maxAttempts: 1
       });
 

rush-plugins/rush-http-build-cache-plugin/src/test/HttpBuildCacheProvider.test.ts

@@ -97,7 +97,7 @@ describe('HttpBuildCacheProvider', () => {
       );
       expect(terminalBuffer.getAllOutputAsChunks({ asLines: true })).toMatchInlineSnapshot(`
 Array [
-  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown bytes[n]",
+  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown length[n]",
   "[warning] Error getting cache entry: Error: Credentials for https://buildcache.example.acme.com/ have not been provided.[n]",
   "[warning] In CI, verify that RUSH_BUILD_CACHE_CREDENTIAL contains a valid Authorization header value.[n]",
   "[warning] [n]",
@@ -160,9 +160,9 @@ Array [
       );
       expect(terminalBuffer.getAllOutputAsChunks({ asLines: true })).toMatchInlineSnapshot(`
 Array [
-  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown bytes[n]",
-  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown bytes[n]",
-  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown bytes[n]",
+  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown length[n]",
+  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown length[n]",
+  "[  debug] [http-build-cache] request: GET https://buildcache.example.acme.com/some-key unknown length[n]",
   "[warning] Could not get cache entry: HTTP 504: Gateway Timeout[n]",
 ]
 `);