Remove null/nullable parameter from DistributedApplicationExecutionContext (#8533)

Author: sebastienros

src/Aspire.Hosting/DistributedApplicationBuilder.cs

@@ -130,7 +130,8 @@ private DistributedApplicationExecutionContextOptions BuildExecutionContextOptio
         {
             DistributedApplicationOperation.Run => new DistributedApplicationExecutionContextOptions(operation),
             DistributedApplicationOperation.Inspect => new DistributedApplicationExecutionContextOptions(operation),
-            _ => new DistributedApplicationExecutionContextOptions(operation, _innerBuilder.Configuration["Publishing:Publisher"])
+            DistributedApplicationOperation.Publish => new DistributedApplicationExecutionContextOptions(operation, _innerBuilder.Configuration["Publishing:Publisher"] ?? "manifest"),
+            _ => throw new DistributedApplicationException("Invalid operation specified. Valid operations are 'publish', 'inspect', or 'run'.")
         };
     }
 

src/Aspire.Hosting/DistributedApplicationExecutionContext.cs

@@ -36,7 +36,7 @@ public DistributedApplicationExecutionContext(DistributedApplicationOperation op
     /// <summary>
     /// The name of the publisher that is being used if <see cref="Operation"/> is set to <see cref="DistributedApplicationOperation.Publish"/>. 
     /// </summary>
-    public string? PublisherName { get; set; }
+    public string PublisherName { get; set; }
 
     private readonly DistributedApplicationExecutionContextOptions? _options;
 

src/Aspire.Hosting/DistributedApplicationExecutionContextOptions.cs

@@ -12,16 +12,17 @@ public class DistributedApplicationExecutionContextOptions
     /// Constructs a <see cref="DistributedApplicationExecutionContextOptions" />.
     /// </summary>
     /// <param name="operation">Indicates whether the AppHost is running in Publish mode or Run mode.</param>
-    public DistributedApplicationExecutionContextOptions(DistributedApplicationOperation operation) : this(operation, null)
+    public DistributedApplicationExecutionContextOptions(DistributedApplicationOperation operation)
     {
+        this.Operation = operation;
     }
 
     /// <summary>
     /// Constructs a <see cref="DistributedApplicationExecutionContextOptions" />.
     /// </summary>
     /// <param name="operation">Indicates whether the AppHost is running in Publish mode or Run mode.</param>
     /// <param name="publisherName">The publisher name if in Publish mode.</param>
-    public DistributedApplicationExecutionContextOptions(DistributedApplicationOperation operation, string? publisherName = null)
+    public DistributedApplicationExecutionContextOptions(DistributedApplicationOperation operation, string publisherName)
     {
         this.Operation = operation;
         this.PublisherName = publisherName;
@@ -38,7 +39,7 @@ public DistributedApplicationExecutionContextOptions(DistributedApplicationOpera
     public DistributedApplicationOperation Operation { get; }
 
     /// <summary>
-    /// The name of the publisher if running in pbublish mode.
+    /// The name of the publisher if running in publish mode.
     /// </summary>
     public string? PublisherName { get; }
 }