Add limit to list workflows (#377)

Author: Sushisource

src/Temporalio/Client/TemporalClient.Workflow.cs

@@ -458,6 +458,7 @@ private async IAsyncEnumerable<WorkflowExecution> ListWorkflowsInternalAsync(
                 // Need to combine cancellation token
                 var rpcOptsAndCancelSource = DefaultRetryOptions(input.Options?.Rpc).
                     WithAdditionalCancellationToken(cancellationToken);
+                var yielded = 0;
                 try
                 {
                     var req = new ListWorkflowExecutionsRequest()
@@ -472,6 +473,11 @@ private async IAsyncEnumerable<WorkflowExecution> ListWorkflowsInternalAsync(
                             req, rpcOptsAndCancelSource.Item1).ConfigureAwait(false);
                         foreach (var exec in resp.Executions)
                         {
+                            if (input.Options != null && input.Options.Limit > 0 &&
+                                yielded++ >= input.Options.Limit)
+                            {
+                                yield break;
+                            }
                             yield return new(exec, Client.Options.DataConverter);
                         }
                         req.NextPageToken = resp.NextPageToken;

src/Temporalio/Client/WorkflowListOptions.cs

@@ -13,6 +13,11 @@ public class WorkflowListOptions : ICloneable
         /// </summary>
         public RpcOptions? Rpc { get; set; }
 
+        /// <summary>
+        /// Gets or sets the maximum number of workflows to return. A zero value means no limit.
+        /// </summary>
+        public int Limit { get; set; }
+
         /// <summary>
         /// Create a shallow copy of these options.
         /// </summary>
@@ -28,4 +33,4 @@ public virtual object Clone()
         }
     }
 }
-#endif
+#endif

tests/Temporalio.Tests/Client/TemporalClientWorkflowTests.cs

@@ -272,6 +272,15 @@ await Client.ExecuteWorkflowAsync(
             actualResults.Add(result);
         }
         Assert.Equal(expectedResults, actualResults);
+
+        // Verify limit option works
+        var limitedResults = 0;
+        await foreach (var wf in Client.ListWorkflowsAsync(
+            $"WorkflowId = '{workflowId}'", new() { Limit = 3 }))
+        {
+            limitedResults++;
+        }
+        Assert.Equal(3, limitedResults);
     }
 
     [Workflow]