Addressed copilot pr comments

Author: bachuv

azure-blob-payloads/build.gradle

@@ -72,7 +72,7 @@ test {
     }
 }
 
-// Integration tests require DTS emulator (default localhost:8080) and Azurite on localhost:10000.
+// Integration tests require DTS emulator (default localhost:4001) and Azurite on localhost:10000.
 task integrationTest(type: Test) {
     useJUnitPlatform {
         includeTags 'integration'

azure-blob-payloads/src/main/java/com/microsoft/durabletask/azureblobpayloads/LargePayloadClientExtensions.java

@@ -4,6 +4,8 @@
 
 import com.microsoft.durabletask.DurableTaskGrpcClientBuilder;
 
+import java.util.Objects;
+
 /**
  * Extension methods for enabling externalized payload storage on a {@link DurableTaskGrpcClientBuilder}.
  * <p>
@@ -27,6 +29,8 @@ private LargePayloadClientExtensions() {
     public static DurableTaskGrpcClientBuilder useExternalizedPayloads(
             DurableTaskGrpcClientBuilder builder,
             LargePayloadStorageOptions options) {
+        Objects.requireNonNull(builder, "builder must not be null");
+        Objects.requireNonNull(options, "options must not be null");
         PayloadStore store = new BlobPayloadStore(options);
         builder.addInterceptor(new LargePayloadInterceptor(store, options));
         return builder;
@@ -47,6 +51,9 @@ public static DurableTaskGrpcClientBuilder useExternalizedPayloads(
             DurableTaskGrpcClientBuilder builder,
             PayloadStore store,
             LargePayloadStorageOptions options) {
+        Objects.requireNonNull(builder, "builder must not be null");
+        Objects.requireNonNull(store, "store must not be null");
+        Objects.requireNonNull(options, "options must not be null");
         builder.addInterceptor(new LargePayloadInterceptor(store, options));
         return builder;
     }

azure-blob-payloads/src/main/java/com/microsoft/durabletask/azureblobpayloads/LargePayloadStorageOptions.java

@@ -58,6 +58,10 @@ public int getThresholdBytes() {
      * @throws IllegalArgumentException if the value exceeds 1 MiB
      */
     public LargePayloadStorageOptions setThresholdBytes(int thresholdBytes) {
+        if (thresholdBytes < 0) {
+            throw new IllegalArgumentException(
+                "Payload storage threshold cannot be negative.");
+        }
         if (thresholdBytes > ONE_MIB) {
             throw new IllegalArgumentException(
                 "Payload storage threshold cannot exceed 1 MiB (" + ONE_MIB + " bytes).");
@@ -84,6 +88,10 @@ public int getMaxPayloadBytes() {
      * @return this options object
      */
     public LargePayloadStorageOptions setMaxPayloadBytes(int maxPayloadBytes) {
+        if (maxPayloadBytes <= 0) {
+            throw new IllegalArgumentException(
+                "Maximum payload size must be a positive number of bytes.");
+        }
         this.maxPayloadBytes = maxPayloadBytes;
         return this;
     }

azure-blob-payloads/src/main/java/com/microsoft/durabletask/azureblobpayloads/LargePayloadWorkerExtensions.java

@@ -4,6 +4,8 @@
 
 import com.microsoft.durabletask.DurableTaskGrpcWorkerBuilder;
 
+import java.util.Objects;
+
 /**
  * Extension methods for enabling externalized payload storage on a {@link DurableTaskGrpcWorkerBuilder}.
  * <p>
@@ -29,6 +31,8 @@ private LargePayloadWorkerExtensions() {
     public static DurableTaskGrpcWorkerBuilder useExternalizedPayloads(
             DurableTaskGrpcWorkerBuilder builder,
             LargePayloadStorageOptions options) {
+        Objects.requireNonNull(builder, "builder must not be null");
+        Objects.requireNonNull(options, "options must not be null");
         PayloadStore store = new BlobPayloadStore(options);
         builder.addInterceptor(new LargePayloadInterceptor(store, options));
         builder.setSupportsLargePayloads(true);
@@ -50,6 +54,9 @@ public static DurableTaskGrpcWorkerBuilder useExternalizedPayloads(
             DurableTaskGrpcWorkerBuilder builder,
             PayloadStore store,
             LargePayloadStorageOptions options) {
+        Objects.requireNonNull(builder, "builder must not be null");
+        Objects.requireNonNull(store, "store must not be null");
+        Objects.requireNonNull(options, "options must not be null");
         builder.addInterceptor(new LargePayloadInterceptor(store, options));
         builder.setSupportsLargePayloads(true);
         return builder;

azure-blob-payloads/src/test/java/com/microsoft/durabletask/azureblobpayloads/LargePayloadIntegrationTest.java

@@ -24,8 +24,8 @@
  * <p>
  * These tests require:
  * <ul>
- *   <li>DTS emulator running on localhost:8080:
- *       {@code docker run --name durabletask-emulator -p 8080:8080 -d mcr.microsoft.com/dts/dts-emulator:latest}</li>
+ *   <li>DTS emulator running on localhost:4001:
+ *       {@code docker run --name durabletask-emulator -p 4001:8080 -d mcr.microsoft.com/dts/dts-emulator:latest}</li>
  *   <li>Azurite running on localhost:10000:
  *       {@code docker run --name azurite -p 10000:10000 -p 10001:10001 -p 10002:10002 -d mcr.microsoft.com/azure-storage/azurite}</li>
  * </ul>
@@ -42,7 +42,7 @@ public class LargePayloadIntegrationTest {
     private static final String EMULATOR_ENDPOINT =
         System.getenv("DTS_ENDPOINT") != null
             ? System.getenv("DTS_ENDPOINT")
-            : "http://localhost:8080";
+            : "http://localhost:4001";
 
     private DurableTaskGrpcWorker worker;
     private DurableTaskClient client;

client/src/main/java/com/microsoft/durabletask/DurableTaskGrpcWorker.java

@@ -654,9 +654,11 @@ private void completeOrchestratorTaskWithChunking(OrchestratorResponse response)
         while (isPartial) {
             OrchestratorResponse.Builder chunk = OrchestratorResponse.newBuilder()
                 .setInstanceId(response.getInstanceId())
-                .setCustomStatus(response.getCustomStatus())
                 .setCompletionToken(response.getCompletionToken())
                 .setRequiresHistory(response.getRequiresHistory());
+            if (response.hasCustomStatus()) {
+                chunk.setCustomStatus(response.getCustomStatus());
+            }
 
             while (actionsCompleted < allActions.size()) {
                 OrchestratorAction nextAction = allActions.get(actionsCompleted);

samples/src/main/java/io/durabletask/samples/LargePayloadSample.java

@@ -55,15 +55,13 @@ public static void main(String[] args) throws InterruptedException, TimeoutExcep
             "PAYLOAD_STORAGE_CONNECTION_STRING",
             "UseDevelopmentStorage=true");
 
-        int payloadSizeBytes = Integer.parseInt(
-            envOrDefault("PAYLOAD_SIZE_BYTES", "1572864")); // 1.5 MiB
+        int payloadSizeBytes = intEnvOrDefault("PAYLOAD_SIZE_BYTES", 1572864); // 1.5 MiB
 
-        int externalizeThresholdBytes = Integer.parseInt(
-            envOrDefault("EXTERNALIZE_THRESHOLD_BYTES", "900000"));
+        int externalizeThresholdBytes = intEnvOrDefault("EXTERNALIZE_THRESHOLD_BYTES", 900000);
 
         logger.info(String.format(
-            "Config: payloadSize=%d bytes, threshold=%d bytes, storage=%s",
-            payloadSizeBytes, externalizeThresholdBytes, storageConnectionString));
+            "Config: payloadSize=%d bytes, threshold=%d bytes",
+            payloadSizeBytes, externalizeThresholdBytes));
 
         // --- Payload storage options ---
         LargePayloadStorageOptions payloadOptions = new LargePayloadStorageOptions()
@@ -183,4 +181,20 @@ private static String envOrDefault(String key, String defaultValue) {
         String value = System.getenv(key);
         return (value != null && !value.isEmpty()) ? value : defaultValue;
     }
+
+    private static int intEnvOrDefault(String key, int defaultValue) {
+        String rawValue = System.getenv(key);
+        if (rawValue == null || rawValue.isEmpty()) {
+            return defaultValue;
+        }
+        try {
+            return Integer.parseInt(rawValue);
+        } catch (NumberFormatException e) {
+            logger.warning(String.format(
+                "Invalid integer value for %s: '%s'. Using default value: %d.",
+                key, rawValue, defaultValue));
+            return defaultValue;
+        }
+    }
+
 }