Expose RoutePatternFactory.Combine

[davidfowl]

Background and Motivation

Custom EndpointDataSource implementations need the ability to combine route patterns with the group prefix for custom route grouping semantics.

Proposed API

namespace Microsoft.AspNetCore.Routing.Patterns;

public static class RoutePatternFactory
{
+    public static RoutePattern Combine(RoutePattern? left, RoutePattern right);
}

Usage Examples

var prefixPattern = RoutePatternFactory.Parse("/api");
var pattern = RoutePatternFactory.Parse("/products/{id}");
var combinedPattern = RoutePatternFactory.Combine(prefixPattern, pattern);

Risks

None

[ghost]

Thank you for submitting this for API review. This will be reviewed by @dotnet/aspnet-api-review at the next meeting of the ASP.NET Core API Review group. Please ensure you take a look at the API review process documentation and ensure that:

• The PR contains changes to the reference-assembly that describe the API change. Or, you have included a snippet of reference-assembly-style code that illustrates the API change.
• The PR describes the impact to users, both positive (useful new APIs) and negative (breaking changes).
• Someone is assigned to "champion" this change in the meeting, and they understand the impact and design of the change.

[ghost]

Thanks for contacting us.

We're moving this issue to the .NET 7 Planning milestone for future evaluation / consideration. We would like to keep this around to collect more feedback, which can help us with prioritizing this work. We will re-evaluate this issue, during our next planning meeting(s).
If we later determine, that the issue has no community involvement, or it's very rare and low-impact issue, we will close it - so that the team can focus on more important and high impact issues.
To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[halter73]

API review notes:

1. This is very nice to have when writing your own GetGroupedEndpoints implementation in an EndpointDataSource.
2. Do we think left should be nullable? Yes. It's convenient when called from Endpoints.

API Approved!

namespace Microsoft.AspNetCore.Routing.Patterns;

public static class RoutePatternFactory
{
+    public static RoutePattern Combine(RoutePattern? left, RoutePattern right);
}

[davidfowl]

Fixed