Expose endpoint property expressions to ATS

[sebastienros]

Description

Fixes #15868

TypeScript AppHosts could already reference endpoint properties conceptually through the C# EndpointProperty enum, but EndpointReference.Property(...) was explicitly ignored by ATS, so generated SDKs could not construct expressions such as http://${Host}:${Port} from endpoint properties.

This exposes EndpointReference.Property(EndpointProperty) through ATS, refreshes the generated TypeScript, Python, and Java SDK snapshots, and updates the polyglot validation AppHosts to build an endpoint URL from Host and Port endpoint properties.

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire.dev issue:
      • New issue
  • No

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 16540

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 16540"

[Copilot]

Pull request overview

This PR fixes #15868 by exporting EndpointReference.Property(EndpointProperty) through ATS so polyglot SDKs (TypeScript/Python/Java) can construct endpoint property expressions (e.g., building http://{Host}:{Port}) rather than only referencing the endpoint as a whole.

Changes:

• Exports EndpointReference.Property(EndpointProperty) (previously ignored by ATS) to enable endpoint-property expressions in generated SDKs.
• Regenerates TypeScript, Python, and Java SDK snapshot outputs to include the new property(...) capability.
• Updates the polyglot validation AppHosts (TS/Python/Java) to build and use an endpoint URL expression from Host + Port.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/PolyglotAppHosts/Aspire.Hosting/TypeScript/apphost.ts	Uses EndpointProperty.Host/Port via endpoint.property(...) to form a URL expression and sets it as an env var.
tests/PolyglotAppHosts/Aspire.Hosting/Python/apphost.py	Builds a URL ReferenceExpression from endpoint Host/Port property expressions and uses it in environment configuration.
tests/PolyglotAppHosts/Aspire.Hosting/Java/AppHost.java	Builds a URL expression from endpoint HOST/PORT property expressions and uses it in environment configuration.
tests/Aspire.Hosting.CodeGeneration.TypeScript.Tests/Snapshots/TwoPassScanningGeneratedAspire.verified.ts	Snapshot update adding EndpointReference.property(EndpointProperty) to the generated TS surface.
tests/Aspire.Hosting.CodeGeneration.Python.Tests/Snapshots/TwoPassScanningGeneratedAspire.verified.py	Snapshot update adding EndpointReference.property(...) to the generated Python surface.
tests/Aspire.Hosting.CodeGeneration.Java.Tests/Snapshots/TwoPassScanningGeneratedAspire.verified.java	Snapshot update adding EndpointReference.property(EndpointProperty) to the generated Java surface.
src/Aspire.Hosting/ApplicationModel/EndpointReference.cs	Exports the Property(EndpointProperty) API via [AspireExport] so ATS can surface it in generated SDKs.

[github-actions]

Re-running the failed jobs in the CI workflow for this pull request because 1 job was identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

• Tests / Cli.EndToEnd-JavaPolyglotTests / Cli.EndToEnd-JavaPolyglotTests (ubuntu-latest) - Failed step 'Set up .NET Core' matched the transient annotation allowlist.

[github-actions]

Re-running the failed jobs in the CI workflow for this pull request because 2 jobs were identified as retry-safe transient failures in the CI run attempt.
GitHub was asked to rerun all failed jobs for that attempt, and the rerun is being tracked in the rerun attempt.
The job links below point to the failed attempt jobs that matched the retry-safe transient failure rules.

• Tests / Cli.EndToEnd-KubernetesDeployWithRabbitMQTests / Cli.EndToEnd-KubernetesDeployWithRabbitMQTests (ubuntu-latest) - Failed step 'Run nuget dependent tests (Linux/macOS)' will be retried because the job log matched a configurable test-retry pattern: MCR registry rate limiting (HTTP 403)
• Tests / Hosting.Testing / Hosting.Testing (ubuntu-latest) - Test execution failure will be retried because 1 failed test(s) matched transient test failure patterns (MCR registry rate limiting (HTTP 403)).

Matched test failure patterns (1 test)

• Aspire.Cli.EndToEnd.Tests.KubernetesDeployWithRabbitMQTests.DeployK8sWithRabbitMQ — MCR registry rate limiting (HTTP 403)