Fail cleanly when AppHost selection would require a prompt in non-interactive mode

[shauryalowkeygotaura]

Description

Fixes #17619

When no AppHost is found in the current directory but other AppHosts are running on the system, aspire describe --non-interactive (and the other commands that resolve a running AppHost: logs, stop, wait, export, telemetry, mcp) fell through to the interactive "Select from all running AppHosts" prompt. The prompt guard then threw, surfacing as:

❌ An unexpected error occurred: This prompt requires interactive input but the CLI is running in non-interactive mode...

with the generic unexpected-error exit code, which is not diagnosable from CI scripts.

AppHostConnectionResolver now checks ICliHostEnvironment.SupportsInteractiveInput before either selection prompt:

• Only out-of-scope AppHosts running → returns the command's standard not-found error (e.g. The AppHost is not running.) with CliExitCodes.FailedToFindProject.
• Multiple in-scope AppHosts → returns a new actionable error: "Multiple running AppHosts were found, but the CLI is running in non-interactive mode. Pass --apphost to specify which AppHost to use.", also with FailedToFindProject.

Interactive behavior is unchanged. To give the resolver access to the host environment, ICliHostEnvironment was added to CommonCommandServices (DI-provided) and passed through at each construction site.

Testing

• Added ResolveConnectionAsync_NonInteractiveWithOnlyOutOfScopeAppHosts_ReturnsNotFoundError and ResolveConnectionAsync_NonInteractiveWithMultipleInScopeAppHosts_ReturnsActionableError
• dotnet test --project tests/Aspire.Cli.Tests -- --filter-class "*AppHostConnectionResolverTests" --filter-class "*DescribeCommandTests" --filter-class "*StopCommandTests" --filter-class "*WaitCommandTests" --filter-class "*ExportCommandTests": 79/79 passing locally

🤖 Generated with Claude Code

[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 -- 18079

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 18079"

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR adds non-interactive mode handling to the AppHostConnectionResolver, ensuring that when the CLI runs in non-interactive mode (e.g., in CI/CD pipelines or scripts), it returns clear, actionable error messages instead of attempting interactive prompts that would fail.

Changes:

• Added ICliHostEnvironment dependency to AppHostConnectionResolver and CommonCommandServices to detect non-interactive mode
• Added early-return error paths in ResolveConnectionAsync when multiple AppHosts require user selection but interactive input is unavailable
• Added new localized resource string MultipleAppHostsNonInteractive with translations across all supported languages

Reviewed changes

Copilot reviewed 29 out of 30 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/Aspire.Cli/Backchannel/AppHostConnectionResolver.cs	Core logic: adds non-interactive guards before interactive prompts
src/Aspire.Cli/Commands/CommonCommandServices.cs	Adds ICliHostEnvironment as a service property
src/Aspire.Cli/Commands/*.cs (11 files)	Pass services.HostEnvironment to AppHostConnectionResolver
src/Aspire.Cli/Resources/SharedCommandStrings.resx	New resource string for the non-interactive error
src/Aspire.Cli/Resources/xlf/*.xlf (12 files)	Localization entries for the new string
tests/Aspire.Cli.Tests/Backchannel/AppHostConnectionResolverTests.cs	New tests for non-interactive scenarios; updates existing tests with new parameter
tests/Aspire.Cli.Tests/NuGet/NuGetPackagePrefetcherTests.cs	Updates CommonCommandServices constructor calls with extra null!

Files not reviewed (1)

• src/Aspire.Cli/Resources/SharedCommandStrings.Designer.cs: Language not supported

[JamesNK]

According to the test this displays AppHostNotRunning resource string (No running AppHost found. Use 'aspire run' to start one first.)

I think a message like "No running AppHost found in the current scope. Pass --apphost to specify an AppHost running outside the current scope." would be more useful. Maybe even include the scope in the error message.

I think the most likely situation here is there is a running app host that someone wants to get information from, but describe wasn't called in the right directory or with the right options to get data from it.

[Copilot]

Copilot's findings

Files not reviewed (1)

• src/Aspire.Cli/Resources/SharedCommandStrings.Designer.cs: Language not supported

• Files reviewed: 29/30 changed files
• Comments generated: 0 new