Allow TaskHubClient's CreateOrchestrationInstanceAsync to schedule or…

…chestrators (#1107)

Test/DurableTask.Core.Tests/TaskHubClientTests.cs

@@ -0,0 +1,73 @@
+//  ----------------------------------------------------------------------------------
+//  Copyright Microsoft Corporation
+//  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//  http://www.apache.org/licenses/LICENSE-2.0
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
+//  ----------------------------------------------------------------------------------
+
+#nullable enable
+namespace DurableTask.Core.Tests
+{
+    using DurableTask.Core.History;
+    using DurableTask.Emulator;
+    using Microsoft.VisualStudio.TestTools.UnitTesting;
+    using System;
+    using System.Collections.Generic;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// A test implementation of <see cref="LocalOrchestrationService"/> that captures messages for later inspection.
+    /// </summary>
+    public class TestLocalOrchestrationService : LocalOrchestrationService
+    {
+        public List<TaskMessage> Messages { get; } = new List<TaskMessage>();
+
+        public override Task CreateTaskOrchestrationAsync(TaskMessage creationMessage, OrchestrationStatus[] dedupeStatuses)
+        {
+            // capture message for later inspection
+            this.Messages.Add(creationMessage);
+
+            // call base implementation
+            return base.CreateTaskOrchestrationAsync(creationMessage, dedupeStatuses);
+        }
+    }
+
+    [TestClass]
+    public class TaskHubClientTests
+    {
+        /// <summary>
+        /// Tests that scheduled orchestrations can be created.
+        /// </summary>
+        [TestMethod]
+        public async Task CanCreateScheduledOrchestrations()
+        {
+            // create test orchestration service that allows us to inspect the generated HistoryEvents
+            TestLocalOrchestrationService service = new TestLocalOrchestrationService();
+            TaskHubClient client = new TaskHubClient(service);
+
+            // orchestrator should fire in 5 minutes
+            DateTime fireAt = DateTime.UtcNow.AddMinutes(5);
+
+            // invoke client method
+            await client.CreateOrchestrationInstanceAsync(
+                name: "TestOrchestration", version: "", instanceId: null, input: null, tags: null, dedupeStatuses: null, startAt: fireAt);
+
+            var messages = service.Messages;
+            Assert.IsTrue(messages.Count == 1);
+
+            TaskMessage startMessage = messages[0];
+            HistoryEvent durableEvent = startMessage.Event;
+            Assert.IsInstanceOfType(durableEvent, typeof(ExecutionStartedEvent));
+
+            // we expect the generated history event to have a populated ScheduledStartTime with value provided to the client.
+            ExecutionStartedEvent startEvent = (ExecutionStartedEvent)durableEvent;
+            Assert.IsTrue(startEvent.ScheduledStartTime == fireAt);
+        }
+    }
+}