ci: also build on Windows

Test that we can also be built on Windows. This test ensures that developers using a Windows
machine can build everything.

.github/workflows/_build-rust.yml

@@ -2,11 +2,21 @@
 # More info: https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_iduses
 
 # Common Rust CI setup that checkout the repo, installs the common toolchain
-# and set's up the cargo cache. It builds, tests, and lints the code.
+# and set's up the cargo cache. It builds, tests, and lints the code, but is
+# configurable. This way, the same workflow can be used to build, test, and lint
+# all in different steps, but with the same cache.
 
 on:
   workflow_call:
     inputs:
+      runs-on:
+        type: string
+        required: false
+        default: ubuntu-latest
+        description: |
+          The value for the "runs-on" property: e.g.
+          - ubuntu-latest
+          - windows-latest
       rust-version:
         type: string
         required: false
@@ -22,7 +32,14 @@ on:
         required: false
         # Make sure we always an empty string to "--features <FEATURES>"
         default: '""'
-        description: Comma-separated String with additional Rust features relevant for a certain job.
+        description: >
+          Comma-separated string with additional crate features. Empty string by
+          default. CAUTION: For Windows CI runners, this must be '""' as is,
+          i.e., the string itself must be "". This is a limitation of the
+          Windows power shell. This might be configured like this:
+
+          features: >
+            '""'
       do-style-check:
         type: boolean
         required: false
@@ -35,8 +52,8 @@ on:
         description: Execute tests.
 
 jobs:
-  check_rust:
-    runs-on: ubuntu-latest
+  rust:
+    runs-on: ${{ inputs.runs-on }}
     steps:
       - name: Check out
         uses: actions/checkout@v3
@@ -67,16 +84,23 @@ jobs:
       - name: Build (all targets)
         run: cargo build --all-targets --features ${{ inputs.features }}
       - name: Code Formatting
-        if: ${{ inputs.do-style-check }}
+        if: inputs.do-style-check
         run: cargo fmt --all -- --check
       - name: Code Style and Doc Style
-        if: ${{ inputs.do-style-check }}
+        if: inputs.do-style-check
         run: |
           cargo doc --document-private-items --features ${{ inputs.features }}
           cargo clippy --all-targets --features ${{ inputs.features }}
-      - name: Unit Test
-        if: ${{ inputs.do-test }}
+      - name: Unit Test (UNIX)
+        if: inputs.do-test && runner.os != 'Windows'
         run: |
           curl -LsSf https://get.nexte.st/latest/linux | tar zxf -
           chmod u+x cargo-nextest
           ./cargo-nextest nextest run --features ${{ inputs.features }}
+      - name: Unit Test (Windows)
+        if: inputs.do-test && runner.os == 'Windows'
+        run: |
+          Invoke-WebRequest https://get.nexte.st/latest/windows -OutFile cargo-nextest.zip
+          Expand-Archive .\cargo-nextest.zip
+          cp .\cargo-nextest/cargo-nextest.exe .
+          .\cargo-nextest.exe nextest run --features ${{ inputs.features }}

.github/workflows/rust.yml

@@ -57,6 +57,20 @@ jobs:
       do-style-check: false
       rust-target: thumbv7em-none-eabihf
 
+  # We perform one single run also in Windows. This should be sufficient to
+  # check that devs can also use this on Windows.
+  build_nostd_stable_windows:
+    name: build no_std (stable) [Windows]
+    uses: ./.github/workflows/_build-rust.yml
+    with:
+      runs-on: windows-latest
+      # Quirk for the Windows powershell and its handling of empty arguments.
+      features: >
+        '""'
+      rust-version: stable
+      do-style-check: false
+      rust-target: thumbv7em-none-eabihf
+
   build_nostd_nightly:
     name: build no_std (nightly)
     needs: build_nightly