Address feedback to WithUrls()

[DamianEdwards]

Description

Addresses feedback received about using WithUrls():

• URL callbacks are now run later, during the BeforeResourceStarted event processing
• Multiple URLs associated with the same endpoint are now properly supported and will be displayed on the dashboard
• URLs that are not associated with an endpoint now aren't active until the resource enters the "Running" state
• Added new overloads of WithUrl that accept ReferenceExpression and interpolated string
• Tweaked doc comments to make it clearer when URLs are added vs. updated
• Added new tests

Fixes #8587

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
• Does the change make any security assumptions or guarantees?
  • [ x No
• Does the change require an update in our Aspire docs?
  • Yes
    • Is this introducing a breaking change?
      • No
        • Link to aspire-docs issue: [New article]: Customizing resource URLs using new API added in 9.2 docs-aspire#2936

[Copilot]

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

tests/Aspire.Hosting.Tests/WithUrlsTests.cs:47

• [nitpick] The test method name 'WithUrlsCallsCallbackAfterBeforeResourceStartedEvent' is ambiguous due to the repeated 'AfterBefore' phrasing. Consider renaming it to 'WithUrlsCallsCallbackAfterResourceStartedEvent' for clarity.

public async Task WithUrlsCallsCallbackAfterBeforeResourceStartedEvent()

src/Aspire.Hosting/Dcp/ResourceSnapshotBuilder.cs:213

• The use of the null-forgiving operator on 'endpointUrl.Endpoint' assumes this property is never null. Consider adding a null-check or ensuring via code invariants that 'endpointUrl.Endpoint' is always set to avoid potential runtime exceptions.

urls.Add(new(Name: endpointUrl.Endpoint!.EndpointName, Url: endpointUrl.Url, IsInternal: false) { IsInactive = isInactive, DisplayProperties = new(endpointUrl.DisplayText ?? "", endpointUrl.DisplayOrder ?? 0) });

[DamianEdwards]

/backport to release/9.2

[github-actions]

Started backporting to release/9.2: https://github.com/dotnet/aspire/actions/runs/14321482119

[davidfowl]

What happens if this fails?

[DamianEdwards]

Good question given it's user code. This didn't change in this PR of course, but there's no error handling here right now. I see that the environment callback stuff doesn't handle errors in its callbacks either though.

[davidfowl]

So same experience, failed to start