Fixing the case null session state was being set as empty byte array. They are not the same. Setting session state to null properly cleans up session state in service bus. (#1228)

yvgopal · web-flow · commit 62c192457300 · 2025-06-20T16:21:59.000-07:00
diff --git a/src/DurableTask.ServiceBus/Common/Abstraction/ServiceBusAbstraction.cs b/src/DurableTask.ServiceBus/Common/Abstraction/ServiceBusAbstraction.cs
@@ -140,7 +140,9 @@ public async Task SetStateAsync(byte[] sessionState)
         {
             if (sessionState == null)
             {
-                await this.sessionReceiver.SetSessionStateAsync(new BinaryData(new byte[] { }));
+                // Setting session state to null is equivalent to deleting session state.
+                // Setting session state to empty byte array is not equivalent to deleting session state.
+                await this.sessionReceiver.SetSessionStateAsync(null);
             }
             else
             {

Original file line number	Diff line number	Diff line change
`@@ -140,7 +140,9 @@ public async Task SetStateAsync(byte[] sessionState)`
`140`	`140`	`{`
`141`	`141`	`if (sessionState == null)`
`142`	`142`	`{`
`143`		`- await this.sessionReceiver.SetSessionStateAsync(new BinaryData(new byte[] { }));`
	`143`	`+ // Setting session state to null is equivalent to deleting session state.`
	`144`	`+ // Setting session state to empty byte array is not equivalent to deleting session state.`
	`145`	`+ await this.sessionReceiver.SetSessionStateAsync(null);`
`144`	`146`	`}`
`145`	`147`	`else`
`146`	`148`	`{`