ci: run tests on Windows and macOS (#923)

Adds Windows and macOS to the unit and integration test matrices to catch
cross-platform regressions automatically (path separators, shell quoting,
.cmd shim resolution, etc.). Linux keeps the full matrix (Electron 37 +
latest, VS Code 1.106.0 + stable); Windows and macOS each run a single
latest/stable smoke job. OS versions are pinned
(ubuntu-24.04, windows-2025, macos-15) for reproducibility.

Closes #882

Author: EhabY

.github/workflows/ci.yaml

@@ -28,14 +28,19 @@ jobs:
       - run: pnpm build
 
   test-unit:
-    name: Unit Test (Electron ${{ matrix.electron-version }})
-    runs-on: ubuntu-24.04
+    name: Unit Test (${{ matrix.name }}, Electron ${{ matrix.electron-version }})
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         # Minimum supported version: VS Code 1.106 (Oct 2025) -> Electron 37 -> Node 22
-        # See https://github.com/ewanharris/vscode-versions for version mapping
-        electron-version: ["37", "latest"]
+        # See https://github.com/ewanharris/vscode-versions for version mapping.
+        # Older Electron stays Linux-only; "latest" smoke-tests Windows + macOS too.
+        include:
+          - { os: ubuntu-24.04, name: Linux, electron-version: "37" }
+          - { os: ubuntu-24.04, name: Linux, electron-version: "latest" }
+          - { os: windows-2025, name: Windows, electron-version: "latest" }
+          - { os: macos-15, name: macOS, electron-version: "latest" }
 
     steps:
       - uses: actions/checkout@v6
@@ -44,16 +49,21 @@ jobs:
 
       - name: Run tests with Electron ${{ matrix.electron-version }}
         run: ./scripts/test-electron.sh ${{ matrix.electron-version }}
+        shell: bash
         env:
           CI: true
 
   test-integration:
-    name: Integration Test (VS Code ${{ matrix.vscode-version }})
-    runs-on: ubuntu-24.04
+    name: Integration Test (${{ matrix.name }}, VS Code ${{ matrix.vscode-version }})
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
-        vscode-version: ["1.106.0", "stable"]
+        include:
+          - { os: ubuntu-24.04, name: Linux, vscode-version: "1.106.0" }
+          - { os: ubuntu-24.04, name: Linux, vscode-version: "stable" }
+          - { os: windows-2025, name: Windows, vscode-version: "stable" }
+          - { os: macos-15, name: macOS, vscode-version: "stable" }
 
     steps:
       - uses: actions/checkout@v6
@@ -63,7 +73,9 @@ jobs:
       - run: pnpm build
 
       - name: Run integration tests on VS Code ${{ matrix.vscode-version }}
-        run: xvfb-run -a pnpm test:integration --label "VS Code ${{ matrix.vscode-version }}"
+        # xvfb only exists on Linux; on Windows/macOS the runner has a real display.
+        run: ${{ runner.os == 'Linux' && 'xvfb-run -a' || '' }} pnpm test:integration --label "VS Code ${{ matrix.vscode-version }}"
+        shell: bash
 
   package:
     name: Package