ci: add windows coverage

.github/workflows/ci.yaml

@@ -29,16 +29,33 @@ jobs:
       # Will look like ["<version from .bazelversion>", "5.3.2"]
       bazelversions: ${{ toJSON(steps.*.outputs.bazelversion) }}
 
+  matrix-prep-os:
+    # Prepares the 'os' axis of the test matrix
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - id: linux
+        run: echo "os=ubuntu-latest" >> $GITHUB_OUTPUT
+      - id: windows
+        run: echo "os=windows-latest" >> $GITHUB_OUTPUT
+        # Only run on main branch (not PRs) to minimize windows minutes (billed at 2X)
+        # https://docs.github.com/en/billing/managing-billing-for-github-actions/about-billing-for-github-actions#included-storage-and-minutes
+        if: (github.ref == 'refs/heads/main' || contains(github.head_ref, 'windows'))
+    outputs:
+      # Will look like ["ubuntu-latest", "windows-latest"]
+      os: ${{ toJSON(steps.*.outputs.os) }}
+
   test:
     # The type of runner that the job will run on
     runs-on: ${{ matrix.os }}
     needs:
       - matrix-prep-bazelversion
+      - matrix-prep-os
 
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest]
+        os: ${{ fromJSON(needs.matrix-prep-os.outputs.os) }}
         bazelversion: ${{ fromJSON(needs.matrix-prep-bazelversion.outputs.bazelversions) }}
         folder:
           - .
@@ -58,6 +75,12 @@ jobs:
           # TODO: fix
           - folder: e2e/wasm
             bzlmodEnabled: true
+          # Let's opt-in to individual tests here to start
+          - os: windows-latest
+        include:
+          - os: windows-latest
+            folder: e2e/smoke
+
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps:
       # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it