Refactor GitHub Actions workflow for cross-platform compatibility

.github/workflows/test.yml

@@ -7,9 +7,17 @@ on:
     branches: [ "main" ]
 
 jobs:
-
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        arch: [amd64, arm64, 386]
+        exclude:
+          - os: windows-latest
+            arch: arm64
+          - os: macos-latest
+            arch: 386
     env:
       FISKALHRGO_TEST_CERT_PATH: ${{ secrets.FISKALHRGO_TEST_CERT_PATH }}
       FISKALHRGO_TEST_CERT_PASSWORD: ${{ secrets.FISKALHRGO_TEST_CERT_PASSWORD }}
@@ -20,17 +28,46 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.23.1'
+        go-version: 'stable'
 
-    - name: Build
-      run: go build -v ./...
+    - name: Set TEMP_DIR environment variable
+      run: echo "TEMP_DIR=$(mktemp -d)" >> $GITHUB_ENV
+      shell: bash
+
+    - name: Set TEMP_DIR environment variable for Windows
+      if: runner.os == 'Windows'
+      run: echo "TEMP_DIR=%TEMP%" >> $GITHUB_ENV
+      shell: cmd
 
-    # Decode and save the P12 certificate (needed for tests)
     - name: Decode and save the P12 certificate
       run: |
-        echo "$CIS_P12_BASE64" | base64 -d > /tmp/fiskal.p12
+        go run -mod=mod - <<EOF
+        package main
+
+        import (
+            "encoding/base64"
+            "io/ioutil"
+            "os"
+        )
+
+        func main() {
+            data, err := base64.StdEncoding.DecodeString(os.Getenv("CIS_P12_BASE64"))
+            if err != nil {
+                panic(err)
+            }
+            err = ioutil.WriteFile(os.Getenv("TEMP_DIR")+"/fiskal.p12", data, 0644)
+            if err != nil {
+                panic(err)
+            }
+        }
+        EOF
       env:
         CIS_P12_BASE64: ${{ secrets.CIS_P12_BASE64 }}
 
+    - name: Build
+      run: go build -v ./...
+
     - name: Test
       run: go test -v ./...
+      env:
+        FISKALHRGO_TEST_CERT_PATH: $TEMP_DIR/fiskal.p12