Endpoint for updating task name

backend/src/Designer/Controllers/ProcessModelingController.cs

@@ -73,5 +73,27 @@ public async Task<FileStreamResult> SaveProcessDefinitionFromTemplate(string org
             Stream processDefinitionStream = _processModelingService.GetProcessDefinitionStream(editingContext);
             return new FileStreamResult(processDefinitionStream, MediaTypeNames.Text.Plain);
         }
+
+        [HttpPut("tasks/{taskId}/{taskName}")]
+        public async Task<ActionResult> UpdateProcessTaskName(string org, string repo, string taskId, string taskName, CancellationToken cancellationToken)
+        {
+            Guard.AssertArgumentNotNull(taskId, nameof(taskId));
+            Guard.AssertArgumentNotNull(taskName, nameof(taskName));
+            string developer = AuthenticationHelper.GetDeveloperUserName(HttpContext);
+            var editingContext = AltinnRepoEditingContext.FromOrgRepoDeveloper(org, repo, developer);
+            try
+            {
+                Stream updatedProcessDefinitionStream = await _processModelingService.UpdateProcessTaskNameAsync(editingContext, taskId, taskName, cancellationToken);
+                return new FileStreamResult(updatedProcessDefinitionStream, MediaTypeNames.Text.Plain);
+            }
+            catch (InvalidOperationException)
+            {
+                return BadRequest("Could not deserialize process definition.");
+            }
+            catch (ArgumentException)
+            {
+                return BadRequest("Could not find task with given id.");
+            }
+        }
     }
 }

backend/src/Designer/Services/Implementation/ProcessModeling/ProcessModelingService.cs

@@ -1,9 +1,12 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Xml.Serialization;
+using Altinn.App.Core.Internal.Process.Elements;
 using Altinn.Studio.Designer.Infrastructure.GitRepository;
 using Altinn.Studio.Designer.Models;
 using Altinn.Studio.Designer.Services.Interfaces;
@@ -52,6 +55,37 @@ public Stream GetProcessDefinitionStream(AltinnRepoEditingContext altinnRepoEdit
             return altinnAppGitRepository.GetProcessDefinitionFile();
         }
 
+        public async Task<Stream> UpdateProcessTaskNameAsync(AltinnRepoEditingContext altinnRepoEditingContext, string taskId, string taskName, CancellationToken cancellationToken = default)
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            AltinnAppGitRepository altinnAppGitRepository = _altinnGitRepositoryFactory.GetAltinnAppGitRepository(altinnRepoEditingContext.Org, altinnRepoEditingContext.Repo, altinnRepoEditingContext.Developer);
+            XmlSerializer serializer = new(typeof(Definitions));
+            Definitions? definitions;
+            using (Stream processDefinitionStream = GetProcessDefinitionStream(altinnRepoEditingContext))
+            {
+                definitions = (Definitions?)serializer.Deserialize(processDefinitionStream);
+            }
+
+            if (definitions == null)
+            {
+                throw new InvalidOperationException("Could not deserialize process definition.");
+            }
+
+            ProcessTask? processTask = (definitions.Process.Tasks?.FirstOrDefault(t => t.Id == taskId)) ?? throw new ArgumentException($"Could not find task with id {taskId}.");
+            processTask.Name = taskName;
+
+            Stream processStream = new MemoryStream();
+            serializer.Serialize(processStream, definitions);
+
+            // Reset stream position to beginning after serialization
+            processStream.Seek(0, SeekOrigin.Begin);
+            await altinnAppGitRepository.SaveProcessDefinitionFileAsync(processStream, cancellationToken);
+
+            // Reset stream position to beginning after saving
+            processStream.Seek(0, SeekOrigin.Begin);
+            return processStream;
+        }
+
         private IEnumerable<string> EnumerateTemplateResources(Version version)
         {
             return typeof(ProcessModelingService).Assembly.GetManifestResourceNames()

backend/src/Designer/Services/Interfaces/IProcessModelingService.cs

@@ -39,5 +39,15 @@ public interface IProcessModelingService
         /// <param name="altinnRepoEditingContext">An <see cref="AltinnRepoEditingContext"/>.</param>
         /// <returns>A <see cref="Stream"/> of a process definition file.</returns>
         Stream GetProcessDefinitionStream(AltinnRepoEditingContext altinnRepoEditingContext);
+
+        /// <summary>
+        /// Updates the name of a task in the process definition file.
+        /// </summary>
+        /// <param name="altinnRepoEditingContext">n <see cref="AltinnRepoEditingContext"/>.</param>
+        /// <param name="taskId">The ID of the task to update</param>
+        /// <param name="taskName">The name to set for the task</param>
+        /// <param name="cancellationToken">A <see cref="CancellationToken"/> that observes if operation is cancelled.</param>
+        /// <returns></returns>
+        Task<Stream> UpdateProcessTaskNameAsync(AltinnRepoEditingContext altinnRepoEditingContext, string taskId, string taskName, CancellationToken cancellationToken = default);
     }
 }

backend/tests/Designer.Tests/Controllers/ProcessModelingController/UpdateProcessTaskNameTests.cs

@@ -0,0 +1,54 @@
+using System.Net;
+using System.Net.Http;
+using System.Net.Mime;
+using System.Text;
+using System.Threading.Tasks;
+using System.Xml.Linq;
+using Designer.Tests.Controllers.ApiTests;
+using Designer.Tests.Utils;
+using FluentAssertions;
+using Microsoft.AspNetCore.Mvc.Testing;
+using Xunit;
+
+namespace Designer.Tests.Controllers.ProcessModelingController
+{
+    public class UpdateProcessTaskName : DisagnerEndpointsTestsBase<UpdateProcessTaskName>, IClassFixture<WebApplicationFactory<Program>>
+    {
+        private static string Url(string org, string repository, string taskId, string taskName) => $"/designer/api/{org}/{repository}/process-modelling/tasks/{taskId}/{taskName}";
+
+        public UpdateProcessTaskName(WebApplicationFactory<Program> factory) : base(factory)
+        {
+        }
+
+        [Theory]
+        [InlineData("ttd", "app-with-process", "testUser", "Task_1", "NewTaskName")]
+        public async Task UpdateProcessTaskName_ShouldReturnUpdatedProcess(string org, string app, string developer, string taskId, string taskName)
+        {
+            string targetRepository = TestDataHelper.GenerateTestRepoName();
+            await CopyRepositoryForTest(org, app, developer, targetRepository);
+
+            string url = Url(org, targetRepository, taskId, taskName);
+
+            using var response = await HttpClient.PutAsync(url, null);
+            response.StatusCode.Should().Be(HttpStatusCode.OK);
+
+            string responseContent = await response.Content.ReadAsStringAsync();
+
+            responseContent.Should().NotBeNullOrEmpty();
+            responseContent.Should().Contain(taskName);
+        }
+
+        [Theory]
+        [InlineData("ttd", "app-with-process", "testUser", "Does_not_exist", "NewTaskName")]
+        public async Task InvalidTaskId_ShouldReturnBadRequest(string org, string app, string developer, string taskId, string taskName)
+        {
+            string targetRepository = TestDataHelper.GenerateTestRepoName();
+            await CopyRepositoryForTest(org, app, developer, targetRepository);
+
+            string url = Url(org, targetRepository, taskId, taskName);
+
+            using var response = await HttpClient.PutAsync(url, null);
+            response.StatusCode.Should().Be(HttpStatusCode.BadRequest);
+        }
+    }
+}

backend/tests/Designer.Tests/Services/ProcessModelingServiceTests.cs

@@ -1,8 +1,14 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Linq;
+using System.Xml.Serialization;
+using Altinn.App.Core.Internal.Process.Elements;
+using Altinn.Studio.Designer.Factories;
+using Altinn.Studio.Designer.Models;
 using Altinn.Studio.Designer.Services.Implementation.ProcessModeling;
 using Altinn.Studio.Designer.Services.Interfaces;
+using Designer.Tests.Utils;
 using FluentAssertions;
 using Moq;
 using SharedResources.Tests;
@@ -30,6 +36,34 @@ public void GetProcessDefinitionTemplates_GivenVersion_ReturnsListOfTemplates(st
             }
         }
 
+        [Theory]
+        [InlineData("ttd", "app-with-process", "testUser", "Task_1", "NewTaskName")]
+        public async void UpdateProcessTaskNameAsync_GivenTaskIdAndTaskName_UpdatesTaskName(string org, string repo, string developer, string taskId, string newTaskName)
+        {
+            // Arrange
+            string targetRepository = TestDataHelper.GenerateTestRepoName();
+            var editingContext = AltinnRepoEditingContext.FromOrgRepoDeveloper(org, targetRepository, developer);
+            await TestDataHelper.CopyRepositoryForTest(org, repo, developer, targetRepository);
+
+            try
+            {
+                var altinnGitRepositoryFactory = new AltinnGitRepositoryFactory(TestDataHelper.GetTestDataRepositoriesRootDirectory());
+                IProcessModelingService processModelingService = new ProcessModelingService(altinnGitRepositoryFactory);
+
+                // Act
+                using Stream result = await processModelingService.UpdateProcessTaskNameAsync(editingContext, taskId, newTaskName);
+                XmlSerializer serializer = new(typeof(Definitions));
+                Definitions definitions = (Definitions)serializer.Deserialize(result);
+
+                // Assert
+                definitions.Process.Tasks.First(t => t.Id == taskId).Name.Should().Be(newTaskName);
+            }
+            finally
+            {
+                TestDataHelper.DeleteAppRepository(org, targetRepository, developer);
+            }
+        }
+
         public static IEnumerable<object[]> TemplatesTestData => new List<object[]>
         {
             new object[]

backend/tests/Designer.Tests/_TestData/Repositories/testUser/ttd/app-with-process/App/config/process/process.bpmn

@@ -0,0 +1,42 @@
+<bpmn:definitions xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:altinn="http://altinn.no" xmlns:bpmn="http://www.omg.org/spec/BPMN/20100524/MODEL" xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI" xmlns:dc="http://www.omg.org/spec/DD/20100524/DC" xmlns:di="http://www.omg.org/spec/DD/20100524/DI" id="Altinn_SingleDataTask_Process_Definition" targetNamespace="http://bpmn.io/schema/bpmn">
+  <bpmn:process id="SingleDataTask" isExecutable="false">
+    <bpmn:startEvent id="StartEvent_1">
+      <bpmn:outgoing>SequenceFlow_1n56yn5</bpmn:outgoing>
+    </bpmn:startEvent>
+    <bpmn:endEvent id="EndEvent_1">
+      <bpmn:incoming>Flow_1htunjv</bpmn:incoming>
+    </bpmn:endEvent>
+    <bpmn:sequenceFlow id="SequenceFlow_1n56yn5" sourceRef="StartEvent_1" targetRef="Task_1" />
+    <bpmn:task id="Task_1" name="Utfylling">
+      <bpmn:extensionElements>
+        <altinn:taskExtension>
+          <altinn:taskType>data</altinn:taskType>
+        </altinn:taskExtension>
+      </bpmn:extensionElements>
+      <bpmn:incoming>SequenceFlow_1n56yn5</bpmn:incoming>
+      <bpmn:outgoing>Flow_1htunjv</bpmn:outgoing>
+    </bpmn:task>
+    <bpmn:sequenceFlow id="Flow_1htunjv" sourceRef="Task_1" targetRef="EndEvent_1" />
+  </bpmn:process>
+  <bpmndi:BPMNDiagram id="BPMNDiagram_1">
+    <bpmndi:BPMNPlane id="BPMNPlane_1" bpmnElement="SingleDataTask">
+      <bpmndi:BPMNShape id="_BPMNShape_StartEvent_2" bpmnElement="StartEvent_1">
+        <dc:Bounds x="156" y="81" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="Task_1_di" bpmnElement="Task_1">
+        <dc:Bounds x="260" y="59" width="100" height="80" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="EndEvent_1_di" bpmnElement="EndEvent_1">
+        <dc:Bounds x="422" y="81" width="36" height="36" />
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNEdge id="SequenceFlow_1n56yn5_di" bpmnElement="SequenceFlow_1n56yn5">
+        <di:waypoint x="192" y="99" />
+        <di:waypoint x="260" y="99" />
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="Flow_1htunjv_di" bpmnElement="Flow_1htunjv">
+        <di:waypoint x="360" y="99" />
+        <di:waypoint x="422" y="99" />
+      </bpmndi:BPMNEdge>
+    </bpmndi:BPMNPlane>
+  </bpmndi:BPMNDiagram>
+</bpmn:definitions>