test code with all supported Node versions

Author: alexlanz

.github/workflows/main.yml

@@ -2,16 +2,16 @@ name: Test Package
 
 on: push
 
-env:
-  NODE_VERSION: 20
-
 jobs:
   test:
     runs-on: ubuntu-22.04
     timeout-minutes: 15
+    strategy:
+      matrix:
+        node_version: [16, 18, 20]
     steps:
       - uses: actions/checkout@v4
       - uses: aboutbits/github-actions-node/setup-and-install@v2
         with:
-          node-version: ${{ env.NODE_VERSION }}
+          node-version: ${{ matrix.node_version }}
       - run: npm run checks