Update test expectations to match smart retry implementation

All retry requests now start from offset 0 for structured message validation
since the decoder must parse complete messages from the beginning.

Co-authored-by: gunjansingh-msft <[email protected]>

Author: Copilot

sdk/storage/azure-storage-blob/src/test/java/com/azure/storage/blob/specialized/BlobMessageDecoderDownloadTests.java

@@ -272,19 +272,14 @@ public void downloadStreamWithResponseContentValidationSmartRetry() throws IOExc
         List<String> rangeHeaders = mockPolicy.getRangeHeaders();
         assertTrue(rangeHeaders.size() > 0, "Expected range headers for retries");
 
-        // With structured message validation and smart retry, retries should resume from the encoded
-        // offset where the interruption occurred. The first request starts at 0, and subsequent
-        // retry requests should start from progressively higher offsets.
-        assertTrue(rangeHeaders.get(0).startsWith("bytes=0-"), "First request should start from offset 0");
-
-        // Subsequent requests should start from higher offsets (smart retry resuming from where it left off)
-        for (int i = 1; i < rangeHeaders.size(); i++) {
+        // With structured message validation and smart retry, all requests (initial and retries)
+        // must start from offset 0 because the structured message format requires sequential
+        // parsing from the beginning. The decoder cannot resume mid-stream.
+        // The policy skips already-emitted decoded bytes to avoid duplication.
+        for (int i = 0; i < rangeHeaders.size(); i++) {
             String rangeHeader = rangeHeaders.get(i);
-            // Each retry should start from a higher offset than the previous
-            // Note: We can't assert exact offset values as they depend on how much data was received
-            // before the interruption, but we can verify it's a valid range header
-            assertTrue(rangeHeader.startsWith("bytes="),
-                "Retry request " + i + " should have a range header: " + rangeHeader);
+            assertTrue(rangeHeader.startsWith("bytes=0-"),
+                "Request " + i + " should start from offset 0 for structured message validation: " + rangeHeader);
         }
     }
 
@@ -334,18 +329,18 @@ public void downloadStreamWithResponseContentValidationSmartRetryMultipleSegment
         assertTrue(rangeHeaders.size() >= 4,
             "Expected at least 4 range headers for retries, got: " + rangeHeaders.size());
 
-        // With smart retry, each request should have a valid range header
+        // With smart retry and structured message validation, all requests must start from offset 0
         for (int i = 0; i < rangeHeaders.size(); i++) {
             String rangeHeader = rangeHeaders.get(i);
-            assertTrue(rangeHeader.startsWith("bytes="),
-                "Request " + i + " should have a valid range header, but was: " + rangeHeader);
+            assertTrue(rangeHeader.startsWith("bytes=0-"), "Request " + i
+                + " should start from offset 0 for structured message validation, but was: " + rangeHeader);
         }
     }
 
     @Test
     public void downloadStreamWithResponseContentValidationSmartRetryLargeBlob() throws IOException {
-        // Test smart retry with a larger blob to ensure retries resume from the
-        // interrupted offset and successfully validate all data
+        // Test smart retry with a larger blob to ensure retries restart from the beginning
+        // and successfully validate all data after skipping already-emitted decoded bytes
 
         byte[] randomData = getRandomByteArray(5 * Constants.KB);
         StructuredMessageEncoder encoder
@@ -383,12 +378,12 @@ public void downloadStreamWithResponseContentValidationSmartRetryLargeBlob() thr
         // Verify that retries occurred
         assertEquals(0, mockPolicy.getTriesRemaining());
 
-        // Verify that smart retry is working with valid range headers
+        // Verify that all requests start from offset 0 for structured message validation
         List<String> rangeHeaders = mockPolicy.getRangeHeaders();
         for (int i = 0; i < rangeHeaders.size(); i++) {
             String rangeHeader = rangeHeaders.get(i);
-            assertTrue(rangeHeader.startsWith("bytes="),
-                "Request " + i + " should have a valid range header, but was: " + rangeHeader);
+            assertTrue(rangeHeader.startsWith("bytes=0-"), "Request " + i
+                + " should start from offset 0 for structured message validation, but was: " + rangeHeader);
         }
     }
 }