Add WithOrder to IEndpointConventionBuilder

src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs

@@ -126,6 +126,29 @@ public static TBuilder WithGroupName<TBuilder>(this TBuilder builder, string end
         return builder;
     }
 
+    /// <summary>
+    /// Sets the <see cref="RouteEndpointBuilder.Order"/> to the provided <paramref name="order"/> for all
+    /// builders created by <paramref name="builder"/>.
+    /// </summary>
+    /// <param name="builder">The <see cref="IEndpointConventionBuilder"/>.</param>
+    /// <param name="order">The order assigned to the endpoint.</param>
+    /// <returns>The <see cref="IEndpointConventionBuilder"/>.</returns>
+    public static TBuilder WithOrder<TBuilder>(this TBuilder builder, int order) where TBuilder : IEndpointConventionBuilder
+    {
+        builder.Add(builder =>
+        {
+            if (builder is RouteEndpointBuilder routeEndpointBuilder)
+            {
+                routeEndpointBuilder.Order = order;
+            }
+            else
+            {
+                throw new InvalidOperationException("This endpoint does not support Order.");
+            }
+        });      
+        return builder;
+    }
+
     /// <summary>
     /// Disables anti-forgery token validation for all endpoints produced on
     /// the target <see cref="IEndpointConventionBuilder"/>.

src/Http/Routing/src/PublicAPI.Unshipped.txt

@@ -8,6 +8,7 @@ override Microsoft.AspNetCore.Routing.HttpMethodMetadata.ToString() -> string!
 override Microsoft.AspNetCore.Routing.RouteNameMetadata.ToString() -> string!
 override Microsoft.AspNetCore.Routing.SuppressLinkGenerationMetadata.ToString() -> string!
 override Microsoft.AspNetCore.Routing.SuppressMatchingMetadata.ToString() -> string!
+static Microsoft.AspNetCore.Builder.RoutingEndpointConventionBuilderExtensions.WithOrder<TBuilder>(this TBuilder builder, int order) -> TBuilder
 Microsoft.AspNetCore.Builder.RouteShortCircuitEndpointConventionBuilderExtensions
 Microsoft.AspNetCore.Routing.RouteShortCircuitEndpointRouteBuilderExtensions
 static Microsoft.AspNetCore.Builder.RouteShortCircuitEndpointConventionBuilderExtensions.ShortCircuit(this Microsoft.AspNetCore.Builder.IEndpointConventionBuilder! builder, int? statusCode = null) -> Microsoft.AspNetCore.Builder.IEndpointConventionBuilder!

src/Http/Routing/test/UnitTests/Builder/RoutingEndpointConventionBuilderExtensionsTest.cs

@@ -223,6 +223,20 @@ public void FinallyConventions_CanExamineMetadataInFIFOOrder()
         Assert.Equal(new[] { "test-metadata", "inner-metadata", "inner-metadata-2" }, metadata);
     }
 
+    [Fact]
+    public void WithOrder_Func_SetsOrder()
+    {
+        // Arrange
+        var builder = CreateBuilder();
+
+        // Act
+        builder.WithOrder(47);
+
+        // Assert
+        var endpoint = builder.Build() as RouteEndpoint;
+        Assert.Equal(47, endpoint.Order);
+    }
+
     private TestEndpointConventionBuilder CreateBuilder()
     {
         var conventionBuilder = new DefaultEndpointConventionBuilder(new RouteEndpointBuilder(