Build extension in GitHub action; and improve it

Author: alt-romes

.github/workflows/debugger.yaml

@@ -1,24 +1,53 @@
 on: [push]
 name: Debugger CI
 jobs:
+  build-vscode-extension:
+    name: Build vscode-extension
+    runs-on: ubuntu-latest # or macOS-latest, or windows-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: recursive
+      - uses: cachix/install-nix-action@v31
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
+
+      - name: Build extension
+        run: |
+          cd vscode-extension/
+          nix-build
+
+      - name: Upload extension artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: Extension Vsix
+          path: vscode-extension/result/haskell-debugger-extension-0.1.0.vsix
+
   build-ghc-debugger:
     name: Build ghc-debug-adapter
     runs-on: ubuntu-latest # or macOS-latest, or windows-latest
     steps:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
+
       - uses: haskell-actions/setup@v2
         with:
           ghc-version: latest-nightly
           cabal-version: latest
           ghcup-release-channel: https://ghc.gitlab.haskell.org/ghcup-metadata/ghcup-nightlies-0.0.7.yaml
 
-      - name: Build ghc-debug-adapter
-        run: cabal build exe:ghc-debug-adapter
+      - uses: cachix/install-nix-action@v31
+        with:
+          nix_path: nixpkgs=channel:nixos-unstable
 
-      - name: Test ghc-debug-adapter
-        run: |
+      - run: cabal build exe:ghc-debug-adapter
+
+  test-ghc-debugger:
+    name: Test ghc-debug-adapter
+    needs: build-ghc-debugger
+    steps:
+      - run: |
           cd test/integration-tests/
           make clean && make build && make test