fix(cli): honor --source for TypeScript empty AppHost restore by radical · Pull Request #17166 · microsoft/aspire

radical · 2026-05-16T05:10:04Z

Description

What broke

Creating an empty TypeScript AppHost from PR hive packages failed even when the caller explicitly pointed the CLI at that hive:

aspire new aspire-empty --language typescript --source <pr-hive>/packages --version <pr-version>

Instead of creating the project, the command failed during TypeScript code generation with a TypeLoadException for Aspire.TypeSystem.AtsJsonCodeWriter.

Full error from the failing run

RPC server exception:
System.TypeLoadException: Could not load type 'Aspire.TypeSystem.AtsJsonCodeWriter' from assembly 'Aspire.TypeSystem, Version=42.42.42.42, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'.
      at Aspire.Hosting.CodeGeneration.TypeScript.AtsTypeScriptCodeGenerator.RenderTypeScriptExportedValue(JsonNode value, AtsTypeRef typeRef, IReadOnlyDictionary`2 dtoTypesById)
      at Aspire.Hosting.CodeGeneration.TypeScript.AtsTypeScriptCodeGenerator.WriteTypeScriptExportedValueChildren(ExportedValueTreeNode node, IReadOnlyDictionary`2 dtoTypesById, Int32 indentLevel) in /_/src/Aspire.Hosting.CodeGeneration.TypeScript/AtsTypeScriptCodeGenerator.cs:line 907
      at Aspire.Hosting.CodeGeneration.TypeScript.AtsTypeScriptCodeGenerator.GenerateExportedValues(IReadOnlyList`1 exportedValues, IReadOnlyDictionary`2 dtoTypesById) in /_/src/Aspire.Hosting.CodeGeneration.TypeScript/AtsTypeScriptCodeGenerator.cs:line 885
      at Aspire.Hosting.CodeGeneration.TypeScript.AtsTypeScriptCodeGenerator.GenerateAspireSdk(AtsContext context) in /_/src/Aspire.Hosting.CodeGeneration.TypeScript/AtsTypeScriptCodeGenerator.cs:line 666
      at Aspire.Hosting.CodeGeneration.TypeScript.AtsTypeScriptCodeGenerator.GenerateDistributedApplication(AtsContext context) in /_/src/Aspire.Hosting.CodeGeneration.TypeScript/AtsTypeScriptCodeGenerator.cs:line 545
      at Aspire.Hosting.RemoteHost.CodeGeneration.CodeGenerationService.GenerateCode(String language, String assemblyName) in /Users/runner/work/aspire/aspire/src/Aspire.Hosting.RemoteHost/CodeGeneration/CodeGenerationService.cs:line 194
      at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
      at System.Reflection.MethodBaseInvoker.InvokeDirectByRefWithFewArgs(Object obj, Span`1 copyOfArgs, BindingFlags invokeAttr)

❌ An unexpected error occurred: Could not load type 'Aspire.TypeSystem.AtsJsonCodeWriter' from assembly
'Aspire.TypeSystem, Version=42.42.42.42, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'.

Why it broke

aspire new parsed --source, but the empty guest-language scaffolding path dropped it before restoring the prebuilt AppHost packages.

That meant the restore never searched the requested PR hive. NuGet then treated the requested PR version as a minimum version and floated to a different preview package set. The TypeScript generator from that stale package set was loaded next to the PR CLI's Aspire.TypeSystem, and the binary mismatch surfaced as the TypeLoadException.

Fix

This change threads the explicit source through the full guest-language scaffold path:

TemplateInputs.Source → ScaffoldContext → IAppHostServerProject.PrepareAsync → PrebuiltAppHostServer restore

PrebuiltAppHostServer now uses that source for both package-only restore and project-reference closure restore. When an explicit source is supplied, it also restores exact package versions so a missing PR package fails clearly instead of silently resolving another Aspire prerelease.

This intentionally does not change default route-local hive discovery for PR/localhive installs; that belongs with the acquisition coherence work.

Fixes #17159

Validation

dotnet test --project tests/Aspire.Cli.Tests/Aspire.Cli.Tests.csproj --no-launch-profile -- --filter-class "*.Projects.PrebuiltAppHostServerTests" --filter-class "*.Scaffolding.ChannelReseedTests" --filter-not-trait "quarantined=true" --filter-not-trait "outerloop=true"
dotnet test --project tests/Aspire.Cli.Tests/Aspire.Cli.Tests.csproj --no-launch-profile -- --filter-not-trait "quarantined=true" --filter-not-trait "outerloop=true"

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

aspire new aspire-empty --language typescript --source <pr-hive> --version <pr-version> parsed --source, but the empty AppHost TypeScript scaffolding path dropped it before the prebuilt AppHost restored Aspire.Hosting and TypeScript code-generation packages. The bundled restore then searched channel sources, missed the requested PR hive packages, and NuGet floated to a stale preview package set, which later failed with TypeLoadException when the generator loaded against the PR CLI's Aspire.TypeSystem. Flow TemplateInputs.Source into ScaffoldContext, pass it to IAppHostServerProject.PrepareAsync, and have PrebuiltAppHostServer add that source to package and closure restores. When a source override is present, use exact version ranges so restore fails rather than silently resolving a different Aspire prerelease. Fixes microsoft#17159 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

github-actions · 2026-05-16T05:10:56Z

🚀 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 -- 17166

Or

Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 17166"

radical · 2026-05-16T05:23:59Z

There is a second part of the fix that improves this when --source is not passed. And it will be included in #17105 .

Remove whitespace-only changes that are unrelated to the source restore fix, keeping the PR focused on the explicit package source propagation. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

radical · 2026-05-16T06:00:15Z

PR Testing Report

PR Information

PR Number: fix(cli): honor --source for TypeScript empty AppHost restore #17166
Title: fix(cli): honor --source for TypeScript empty AppHost restore
Head Commit: a49d604
Tested At: 2026-05-16T01:53:26.383-04:00

CLI Version Verification

Expected Commit: a49d604
Installed Version: 13.4.0-pr.17166.ga49d604d
Status: ✅ Verified; installed version contains PR commit suffix ga49d604d.

Changes Analyzed

Files Changed

src/Aspire.Cli/Projects/DotNetBasedAppHostServerProject.cs
src/Aspire.Cli/Projects/IAppHostServerProject.cs
src/Aspire.Cli/Projects/PrebuiltAppHostServer.cs
src/Aspire.Cli/Scaffolding/IScaffoldingService.cs
src/Aspire.Cli/Scaffolding/ScaffoldingService.cs
src/Aspire.Cli/Templating/CliTemplateFactory.EmptyTemplate.cs
tests/Aspire.Cli.Tests/Projects/AppHostServerSessionTests.cs
tests/Aspire.Cli.Tests/Projects/PrebuiltAppHostServerTests.cs
tests/Aspire.Cli.Tests/Scaffolding/ChannelReseedTests.cs
tests/Aspire.Cli.Tests/TestServices/FakeFailingAppHostServerProject.cs

Change Categories

CLI changes detected — guest empty-template scaffolding and prebuilt AppHost package restore.
Hosting integration changes
Dashboard changes
Client/Component changes
Template package changes
Test changes detected

Test Scenarios Executed

Scenario 1: PR CLI install + version match

Objective: Install the PR dogfood CLI and verify it matches the PR head commit.
Status: ✅ Passed

Evidence:

Install log: install-output.txt
Version output: version.txt

Scenario 2: TypeScript empty template with explicit PR hive source

Objective: Verify aspire new aspire-empty --language typescript succeeds when --source points to PR packages outside the standard hive discovery location.
Status: ✅ Passed

Command shape:

aspire new aspire-empty --language typescript --name PrSourceTs3 --output <temp>/PrSourceTs3 --version 13.4.0-pr.17166.ga49d604d --localhost-tld false --suppress-agent-init --non-interactive --source <explicit-pr-packages>

Evidence:

Log: scenarios/scenario-1-typescript-explicit-source-short.log
Generated file list: scenarios/scenario-1-typescript-explicit-source-short.files.txt

Observation: The project was created successfully and TypeScript dependencies were installed. This scenario used a short temp HOME with no ~/.aspire/hives directory, so success depended on the explicit --source path.

Scenario 3: TypeScript empty template without explicit source

Objective: Confirm the test setup still exposes the source-dependent failure when the explicit source is omitted.
Status: ✅ Expected failure reproduced

Command shape:

aspire new aspire-empty --language typescript --name NoSourceTs3 --output <temp>/NoSourceTs3 --version 13.4.0-pr.17166.ga49d604d --localhost-tld false --suppress-agent-init --non-interactive

Evidence:

Log: scenarios/scenario-4-typescript-no-source-short.log

Observed error:

Could not load type 'Aspire.TypeSystem.AtsJsonCodeWriter' from assembly 'Aspire.TypeSystem, Version=42.42.42.42, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'.

Observation: This reproduces the issue signature when the explicit package source is not available to the restore path.

Non-applicable attempted scenarios

Python and Go were initially attempted for aspire-empty, but the PR CLI reports that aspire-empty does not support those languages. They were not counted as PR failures.

Summary

Scenario	Status	Notes
PR CLI install/version	✅ Passed	Installed `13.4.0-pr.17166.ga49d604d`.
TypeScript empty with `--source`	✅ Passed	Explicit out-of-hive PR package source succeeded.
TypeScript empty without `--source`	✅ Expected failure	Reproduced original `AtsJsonCodeWriter` `TypeLoadException`.

Overall Result

✅ PR VERIFIED

The downloaded PR CLI honors --source for the reported TypeScript empty AppHost restore path. The contrast run without --source still hits the original failure shape, which confirms the passing scenario is exercising the intended fix.

Copilot

Pull request overview

This PR fixes aspire new aspire-empty --language typescript failures when callers supply --source (e.g., a PR hive) by threading the source override through the empty-template scaffolding path into AppHost server preparation, and ensuring the prebuilt AppHost restore uses that override (including exact-version restores when an explicit source is provided) to avoid mixed-binary package sets.

Changes:

Thread TemplateInputs.Source through ScaffoldContext into IAppHostServerProject.PrepareAsync(...) as packageSourceOverride.
Update PrebuiltAppHostServer restore logic to include the explicit source for both package-only restore and project-closure restore, and restore exact versions when an explicit source is provided.
Add/adjust tests to validate the override is passed through and that restore is invoked with the expected sources/version constraints.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/Aspire.Cli.Tests/TestServices/FakeFailingAppHostServerProject.cs	Updates fake to match new `PrepareAsync` signature with source override.
tests/Aspire.Cli.Tests/Scaffolding/ChannelReseedTests.cs	Adds coverage that scaffolding passes `PackageSourceOverride` into `PrepareAsync`.
tests/Aspire.Cli.Tests/Projects/PrebuiltAppHostServerTests.cs	Adds coverage that bundled restore uses `--source` override and exact-version package args.
tests/Aspire.Cli.Tests/Projects/AppHostServerSessionTests.cs	Updates test fake to match the updated `PrepareAsync` signature.
src/Aspire.Cli/Templating/CliTemplateFactory.EmptyTemplate.cs	Passes `inputs.Source` into `ScaffoldContext.PackageSourceOverride` for empty templates.
src/Aspire.Cli/Scaffolding/ScaffoldingService.cs	Forwards `PackageSourceOverride` into `IAppHostServerProject.PrepareAsync`.
src/Aspire.Cli/Scaffolding/IScaffoldingService.cs	Extends `ScaffoldContext` with `PackageSourceOverride`.
src/Aspire.Cli/Projects/PrebuiltAppHostServer.cs	Applies source override to restore paths; enforces exact version restore when override is set.
src/Aspire.Cli/Projects/IAppHostServerProject.cs	Extends `PrepareAsync` contract to accept an optional `packageSourceOverride`.
src/Aspire.Cli/Projects/DotNetBasedAppHostServerProject.cs	Updates signature to satisfy the extended `IAppHostServerProject` contract.

When an explicit package source is passed to guest AppHost restore, keep the exact-version pinning scoped to Aspire packages because that is the source mapping being overridden. Non-Aspire integration packages should retain normal NuGet minimum-version restore semantics. Also apply the temporary NuGet.config to the project-reference closure restore path instead of only adding sources to the synthetic project. That keeps package source mapping and channel-specific restore settings active when package and project integrations are restored together. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

davidfowl · 2026-05-16T06:52:54Z

 /// </summary>
 internal sealed class PrebuiltAppHostServer : IAppHostServerProject
 {
+    private const string NuGetOrgSource = "https://api.nuget.org/v3/index.json";


chore(cli): remove source restore diff noise

a49d604

Remove whitespace-only changes that are unrelated to the source restore fix, keeping the PR focused on the explicit package source propagation. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

radical marked this pull request as ready for review May 16, 2026 06:02

radical requested review from JamesNK, davidfowl and mitchdenny as code owners May 16, 2026 06:02

Copilot AI review requested due to automatic review settings May 16, 2026 06:02

Copilot started reviewing on behalf of radical May 16, 2026 06:02 View session

Copilot AI reviewed May 16, 2026

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radical added this to the 13.4 milestone May 16, 2026

davidfowl reviewed May 16, 2026

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github-actions Bot mentioned this pull request May 16, 2026

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fix(cli): honor --source for TypeScript empty AppHost restore#17166

fix(cli): honor --source for TypeScript empty AppHost restore#17166
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Description

What broke

Why it broke

Fix

Validation

Checklist

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PR Testing Report

PR Information

CLI Version Verification

Changes Analyzed

Files Changed

Change Categories

Test Scenarios Executed

Scenario 1: PR CLI install + version match

Scenario 2: TypeScript empty template with explicit PR hive source

Scenario 3: TypeScript empty template without explicit source

Non-applicable attempted scenarios

Summary

Overall Result

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radical commented May 16, 2026 •

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