ci: added test checks, updated devcontainer

Author: coderhammer

.devcontainer/Dockerfile

@@ -0,0 +1,12 @@
+FROM node:18
+
+# Install basic development tools
+RUN apt update && apt install -y less man-db sudo
+
+# Ensure default `node` user has access to `sudo`
+ARG USERNAME=node
+RUN echo $USERNAME ALL=\(root\) NOPASSWD:ALL > /etc/sudoers.d/$USERNAME \
+    && chmod 0440 /etc/sudoers.d/$USERNAME
+
+# Set `DEVCONTAINER` environment variable to help with orientation
+ENV DEVCONTAINER=true

.devcontainer/devcontainer.json

@@ -0,0 +1,15 @@
+// See https://containers.dev/implementors/json_reference/ for configuration reference
+{
+	"name": "Untitled Node.js project",
+	"build": {
+		"dockerfile": "Dockerfile"
+	},
+	"remoteUser": "node",
+	"customizations": {
+		"vscode": {
+			"extensions": [
+				"eamodio.gitlens"
+			]
+		}
+	}
+}

.github/workflows/tests.yml

@@ -0,0 +1,26 @@
+name: Tests
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [16.x, 18.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm ci
+    - run: npm run build
+    - run: npm test