ABAP Developer Assistant — @abap Copilot Chat Participant

Internal VS Code extension exposing an @abap Copilot Chat participant for SAP ABAP developers.

Status

Project layout

src/
  extension.ts            entry point — registers the chat participant
  router.ts                dispatches request.command -> handler
  handlers/
    unitTestHandler.ts      /unittest logic (v1, live)
    reviewHandler.ts         /review stub (v3)
  prompts/
    unitTestPrompt.ts        system + user prompt builder for /unittest
  shared/
    types.ts                  shared interfaces (hints, DDIC context)
    hintExtractor.ts           regex-based static analysis of ABAP source
    modelSelector.ts            Copilot model selection with fallback
    adtLookup.ts                 v2 stub for live ADT package/field lookups

Adding a new command (e.g. a future /dump) means: one new handler file in handlers/, one new prompt file in prompts/, one new case in router.ts. Nothing else needs to change.

Running locally

npm install
npm run compile

Then press F5 in VS Code to launch an Extension Development Host. In the new window:

1. Open an .abap file, or paste ABAP code directly.
2. Open Copilot Chat (Ctrl+Alt+I / Cmd+Alt+I).
3. Select some code (or leave nothing selected to use the whole file) and type:

   @abap /unittest
   

Configuration

Packaging for distribution

npx vsce package

This produces a .vsix file.

Distribution via GitHub Releases

The repo ships a workflow (.github/workflows/release.yml) that builds the .vsix and attaches it to a GitHub Release whenever a version tag is pushed:

npm version patch   # or minor/major — bumps package.json + creates a git tag
git push origin main --tags

Once the workflow finishes, install the released .vsix:

gh release download <tag> --repo hmdev-test/abap-copilot-unit-test-agent --pattern '*.vsix'
code --install-extension abap-unit-test-generator-<version>.vsix

(gh is the GitHub CLI; since this repo is private, the person running this must be signed in — gh auth login — and have repo access.) To update, re-run the same two commands with the new tag.

Note: this does not give VS Code automatic background updates the way the public Marketplace does — installing a new version is still a manual gh release download + code --install-extension per person. If true silent auto-update becomes a requirement, that needs a private Open VSX registry (or the public Marketplace) instead of GitHub Releases.

Before wide rollout: confirm with your GitHub Copilot licensing/security owner that routing ABAP source through vscode.lm (Copilot's model access) is approved for your company's code — this uses the developer's existing Copilot subscription and sends code to GitHub/Microsoft/OpenAI infrastructure per Copilot's standard data handling.

Design principles this codebase follows

• No hardcoded model family. modelSelector.ts asks for whatever Copilot model is available rather than pinning to a specific one that may be deprecated later.
• Deterministic facts come from regex, not the LLM. hintExtractor.ts parses method visibility, DB table access, and DI seams directly from the source so the model isn't re-deriving (and potentially getting wrong) facts that code can already tell us for certain.
• Never fabricate DDIC field names. Without a live ADT connection (v2), unknown structures get a * TODO: verify fields comment instead of invented field names — a wrong guess here is worse than an honest gap.
• Code review output stays separate from test generation output (v3 is a distinct command), so a developer asking for a test never gets an unrequested critique of their business logic silently mixed into the same response.
• No auto-applied changes, ever. Suggestions are always chat output for a human to review — nothing in this extension writes to files or transports on its own.