feat: enable C# emitter in playground with backend server by JoshLove-msft · Pull Request #10346 · microsoft/typespec

JoshLove-msft · 2026-04-12T18:40:03Z

Split emitter into emit-generate.ts (Node.js) and emit-generate.browser.ts (browser stub)
Browser stub POSTs code model to playground server for generation
Created .NET playground server (ASP.NET Core) that runs the generator
Added Dockerfile for containerized deployment
Pipeline: ACR build + App Service deployment with managed identity
Bundle upload to blob storage for browser-side emitter loading
Website: added C# to playground with server URL configuration
Fix: explicit ValueExpression conversion in spread expressions to prevent SIGSEGV when ParameterProvider is spread into ValueExpression collections

- Split emitter into emit-generate.ts (Node.js) and emit-generate.browser.ts (browser stub) - Browser stub POSTs code model to playground server for generation - Created .NET playground server (ASP.NET Core) that runs the generator - Added Dockerfile for containerized deployment - Pipeline: ACR build + App Service deployment with managed identity - Bundle upload to blob storage for browser-side emitter loading - Website: added C# to playground with server URL configuration - Fix: explicit ValueExpression conversion in spread expressions to prevent SIGSEGV when ParameterProvider is spread into ValueExpression collections Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…ployment Only add new parameters (PlaygroundBundleBuildScript, PlaygroundServerDockerfile, PlaygroundServerAppName) and server deployment section. No changes to existing publish/ESRP pipeline logic. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

pkg-pr-new · 2026-04-12T18:42:17Z

Open in StackBlitz

npm i https://pkg.pr.new/@typespec/http-client-csharp@10346

commit: 2d85b12

github-actions · 2026-04-12T18:42:47Z

No changes needing a change description found.

JoshLove-msft · 2026-04-12T18:45:25Z

Will have a follow up PR for some UX enhancements to show a compiling spinner and change highlighting.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Azure SDK Bot (azure-sdk) · 2026-04-12T18:53:19Z

You can try these changes here

🛝 Playground	🌐 Website	🛝 VSCode Extension

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Mark Cowlishaw (markcowl)

I think we should be able to test changes using the typespec - PR Tools ci checks, so should update that workflow to ensure proper setup

…und-server

Remove default server URL from browser stub to prevent it from leaking to third-party sites. The URL must be explicitly set via globalThis.__TYPESPEC_PLAYGROUND_SERVER_URL__ by the host site. Moved the URL configuration back to the website playground. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The server URL is hardcoded in the browser stub with no globalThis fallback. No configuration needed from the website. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

JoshLove-msft · 2026-04-13T22:48:35Z

I think we should be able to test changes using the typespec - PR Tools ci checks, so should update that workflow to ensure proper setup

Yes, that would capture the website changes, but the emitter changes would need to be published via the emitter pipeline.

The publish stage didn't set a Node version, defaulting to Node 20 on the agent. The bundle-uploader depends on asset-emitter which requires Node >=22. Added NodeTool@0 step before the bundle upload. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

The publish stage checks out fresh source with the original package.json version (e.g. 0.1.0). The bundle uploader reads this version for latest.json. Added a step to apply the build number (e.g. 0.1.0-beta.12345) before bundling, matching Build-Packages.ps1 behavior. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

ADO template parser was failing on the inline script. Use the auto-set BUILD_BUILDNUMBER environment variable instead of the macro syntax. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

C# emitter sets BuildPrereleaseVersion=true so gets -alpha tag, matching Build-Packages.ps1 behavior. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Server-side (Program.cs): - Request size limit: 10 MB max body via Kestrel - Content-Type validation: must be application/json - JSON parse error handling: returns 400 on invalid JSON - Subprocess timeout: 5 minutes, kills process tree on timeout (504) - Security headers: X-Content-Type-Options, X-Frame-Options, Referrer-Policy Client-side (emit-generate.browser.ts): - Validate response content-type is application/json - Validate response shape: { files: Array<{ path, content }> } - Validate each file entry has string path and content Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Mock responses now include Headers with content-type to match the response validation added in the browser stub. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Checks Content-Length header against a 10 MB limit before parsing the response JSON to protect against unexpectedly large responses. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

…und-server

JoshLove-msft and others added 2 commits April 12, 2026 11:36

microsoft-github-policy-service Bot added meta:website TypeSpec.io updates emitter:client:csharp Issue for the C# client emitter: @typespec/http-client-csharp eng labels Apr 12, 2026

JoshLove-msft commented Apr 12, 2026

View reviewed changes

Comment thread ...erator/Microsoft.TypeSpec.Generator.ClientModel/src/Providers/ScmMethodProviderCollection.cs

fix: restore plugin path resolution in emitter.ts

da56524

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

fix: prettier formatting, cspell words, lint cleanup

b07b370

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

fix: clarify browser stub comment

a6006ff

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

JoshLove-msft commented Apr 13, 2026

View reviewed changes

Comment thread packages/http-client-csharp/playground-server/Program.cs

Timothee Guerin (timotheeguerin) reviewed Apr 13, 2026

View reviewed changes

Comment thread eng/emitters/pipelines/templates/stages/emitter-stages.yml

Comment thread eng/emitters/pipelines/templates/stages/emitter-stages.yml Outdated

Comment thread website/src/components/playground-component/playground.tsx Outdated

Jorge Rangel (jorgerangel-msft) reviewed Apr 13, 2026

View reviewed changes

Comment thread packages/http-client-csharp/playground-server/Dockerfile Outdated

Comment thread packages/http-client-csharp/.dockerignore

Mark Cowlishaw (markcowl) reviewed Apr 13, 2026

View reviewed changes

Comment thread packages/http-client-csharp/emitter/src/emit-generate.browser.ts Outdated

JoshLove-msft and others added 3 commits April 13, 2026 15:39

Merge remote-tracking branch 'upstream/main' into feat/csharp-playgro…

01c4644

…und-server

fix: hardcode server URL in emitter, remove configurability

fadf720

The server URL is hardcoded in the browser stub with no globalThis fallback. No configuration needed from the website. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

JoshLove-msft and others added 5 commits April 13, 2026 15:52

fix: use BUILD_BUILDNUMBER env var in version stamp script

ed629d0

ADO template parser was failing on the inline script. Use the auto-set BUILD_BUILDNUMBER environment variable instead of the macro syntax. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

fix: use alpha/beta version tag based on BuildPrereleaseVersion

b4d53db

C# emitter sets BuildPrereleaseVersion=true so gets -alpha tag, matching Build-Packages.ps1 behavior. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

style: format emitter-stages.yml

700d1b1

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Timothee Guerin (timotheeguerin) reviewed Apr 14, 2026

View reviewed changes

Comment thread eng/emitters/pipelines/templates/stages/emitter-stages.yml

JoshLove-msft force-pushed the feat/csharp-playground-server branch from c36f99a to 5cb4659 Compare April 15, 2026 02:37

fix: add headers to mock responses in browser stub tests

bd34a3c

Mock responses now include Headers with content-type to match the response validation added in the browser stub. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Mark Cowlishaw (markcowl) reviewed Apr 17, 2026

View reviewed changes

Comment thread packages/http-client-csharp/emitter/src/emit-generate.browser.ts

JoshLove-msft and others added 2 commits April 17, 2026 08:15

feat: add response size limit check in browser emitter

cf88a0a

Checks Content-Length header against a 10 MB limit before parsing the response JSON to protect against unexpectedly large responses. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Merge remote-tracking branch 'upstream/main' into feat/csharp-playgro…

2d85b12

…und-server

Mark Cowlishaw (markcowl) approved these changes Apr 21, 2026

View reviewed changes

Jorge Rangel (jorgerangel-msft) approved these changes Apr 21, 2026

View reviewed changes

Timothee Guerin (timotheeguerin) approved these changes Apr 21, 2026

View reviewed changes

JoshLove-msft added this pull request to the merge queue Apr 21, 2026

github-merge-queue Bot removed this pull request from the merge queue due to failed status checks Apr 21, 2026

JoshLove-msft added this pull request to the merge queue Apr 21, 2026

github-merge-queue Bot removed this pull request from the merge queue due to failed status checks Apr 21, 2026

JoshLove-msft added this pull request to the merge queue Apr 21, 2026

Merged via the queue into microsoft:main with commit 3e5df34 Apr 21, 2026
63 of 64 checks passed

JoshLove-msft deleted the feat/csharp-playground-server branch April 21, 2026 21:42

JoshLove-msft mentioned this pull request Apr 23, 2026

Add UploadPlaygroundBundle option to archetype-typespec-emitter.yml Azure/azure-sdk-tools#15278

Closed

JoshLove-msft mentioned this pull request May 1, 2026

fix(http-client-csharp): make emitter browser-bundleable for playground upload #10582

Merged

Navigation Menu

Repository navigation

feat: enable C# emitter in playground with backend server - #10346

feat: enable C# emitter in playground with backend server#10346
JoshLove-msft merged 21 commits into
microsoft:mainfrom
JoshLove-msft:feat/csharp-playground-server

JoshLove-msft commented Apr 12, 2026 •

edited

Loading

Uh oh!

Uh oh!

pkg-pr-new Bot commented Apr 12, 2026 •

edited

Loading

Uh oh!

github-actions Bot commented Apr 12, 2026

Uh oh!

JoshLove-msft commented Apr 12, 2026

Uh oh!

Azure SDK Bot (azure-sdk) commented Apr 12, 2026 •

edited

Loading

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Mark Cowlishaw (markcowl) left a comment

Uh oh!

Uh oh!

JoshLove-msft commented Apr 13, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

Conversation

JoshLove-msft commented Apr 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

pkg-pr-new Bot commented Apr 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

github-actions Bot commented Apr 12, 2026

Uh oh!

JoshLove-msft commented Apr 12, 2026

Uh oh!

Azure SDK Bot (azure-sdk) commented Apr 12, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Mark Cowlishaw (markcowl) left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

JoshLove-msft commented Apr 13, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

6 participants

JoshLove-msft commented Apr 12, 2026 •

edited

Loading

pkg-pr-new Bot commented Apr 12, 2026 •

edited

Loading

Azure SDK Bot (azure-sdk) commented Apr 12, 2026 •

edited

Loading