Add versioning support in durabletask-dotnet(phase1)

src/Abstractions/Abstractions.csproj

@@ -9,6 +9,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Azure.DurableTask.Core" Version="2.17.1" />
     <PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="6.0.0" />
+    <PackageReference Include="Microsoft.Bcl.HashCode" Version="1.1.1" />
     <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="6.0.0" />
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="6.0.0" />
     <PackageReference Include="System.Text.Json" Version="6.0.0" />

src/Abstractions/TaskName.cs

@@ -29,6 +29,41 @@ public TaskName(string name)
         }
     }
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="TaskName"/> struct.
+    /// </summary>
+    /// <param name="name">The name of the task. Providing <c>null</c> will yield the default struct.</param>
+    /// <param name="version">The version of the task.</param>
+    public TaskName(string name, string version)
+    {
+        if (name is null)
+        {
+            if (version is null)
+            {
+                // Force the default struct when null is passed in.
+                this.Name = null!;
+                this.Version = null!;
+            }
+            else
+            {
+                throw new ArgumentException("name must not be null when version is non-null");
+            }
+        }
+        else
+        {
+            if (version is null)
+            {
+                this.Name = name;
+                this.Version = string.Empty; // fallback to the constructor without version parameter
+            }
+            else
+            {
+                this.Name = name;
+                this.Version = version;
+            }
+        }
+    }
+
     /// <summary>
     /// Gets the name of the task without the version.
     /// </summary>
@@ -40,23 +75,22 @@ public TaskName(string name)
     /// <summary>
     /// Gets the version of the task.
     /// </summary>
-    /// <remarks>
-    /// Task versions is currently locked to <see cref="string.Empty" /> as it is not yet integrated into task
-    /// identification. This is being left here as we intend to support it soon.
-    /// </remarks>
+    /// <value>
+    /// The version of the activity task.
+    /// </value>
     public string Version { get; }
 
     /// <summary>
     /// Implicitly converts a <see cref="TaskName"/> into a <see cref="string"/> of the <see cref="Name"/> property value.
     /// </summary>
     /// <param name="value">The <see cref="TaskName"/> to be converted into a string.</param>
-    public static implicit operator string(TaskName value) => value.Name;
+    public static implicit operator string(TaskName value) => value.ToString();
 
     /// <summary>
     /// Implicitly converts a <see cref="string"/> into a <see cref="TaskName"/> value.
     /// </summary>
     /// <param name="value">The string to convert into a <see cref="TaskName"/>.</param>
-    public static implicit operator TaskName(string value) => string.IsNullOrEmpty(value) ? default : new(value);
+    public static implicit operator TaskName(string value) => FromString(value);
 
     /// <summary>
     /// Compares two <see cref="TaskName"/> objects for equality.
@@ -80,6 +114,32 @@ public TaskName(string name)
         return !a.Equals(b);
     }
 
+    /// <summary>
+    /// Parses the taskname string and initializes a new instance of the <see cref="TaskName"/> struct.
+    /// </summary>
+    /// <param name="taskname">The taskname string in format of "Name:Version" or "Name".</param>
+    /// <returns>New <see cref="TaskName"/> instance parsed from taskname string.</returns>
+    public static TaskName FromString(string taskname)
+    {
+        if (string.IsNullOrEmpty(taskname))
+        {
+            return default;
+        }
+
+        string[] parts = taskname.Split(':');
+        if (parts.Length == 1)
+        {
+            return new TaskName(parts[0]);
+        }
+
+        if (parts.Length == 2)
+        {
+            return new TaskName(parts[0], parts[1]);
+        }
+
+        throw new ArgumentException("Invalid task name format: taskname=" + taskname);
+    }
+
     /// <summary>
     /// Gets a value indicating whether to <see cref="TaskName"/> objects
     /// are equal using value semantics.
@@ -88,7 +148,8 @@ public TaskName(string name)
     /// <returns><c>true</c> if the two objects are equal using value semantics; otherwise <c>false</c>.</returns>
     public bool Equals(TaskName other)
     {
-        return string.Equals(this.Name, other.Name, StringComparison.OrdinalIgnoreCase);
+        return string.Equals(this.Name, other.Name, StringComparison.OrdinalIgnoreCase)
+          && string.Equals(this.Version, other.Version, StringComparison.OrdinalIgnoreCase);
     }
 
     /// <summary>
@@ -113,7 +174,7 @@ public override bool Equals(object? obj)
     /// <returns>A 32-bit hash code value.</returns>
     public override int GetHashCode()
     {
-        return StringComparer.OrdinalIgnoreCase.GetHashCode(this.Name);
+        return HashCode.Combine(this.Name, this.Version);
     }
 
     /// <summary>

src/Abstractions/TaskOrchestrationContext.cs

@@ -22,6 +22,11 @@ public abstract class TaskOrchestrationContext
     /// </summary>
     public abstract string InstanceId { get; }
 
+    /// <summary>
+    /// Gets the version of the current orchestration instance.
+    /// </summary>
+    public virtual string? InstanceVersion => null;
+
     /// <summary>
     /// Gets the parent instance or <c>null</c> if there is no parent orchestration.
     /// </summary>

src/Worker/Core/Shims/TaskOrchestrationContextWrapper.cs

@@ -51,6 +51,9 @@ public TaskOrchestrationContextWrapper(
     /// <inheritdoc/>
     public override string InstanceId => this.innerContext.OrchestrationInstance.InstanceId;
 
+    /// <inheritdoc/>
+    public override string InstanceVersion => this.innerContext.Version;
+
     /// <inheritdoc/>
     public override ParentOrchestrationInstance? Parent => this.invocationContext.Parent;