Add unit tests

.github/workflows/go.yml

@@ -0,0 +1,62 @@
+name: Go CI
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: ['1.20', '1.21']
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v4
+      with:
+        go-version: ${{ matrix.go-version }}
+
+    - name: Get dependencies
+      run: go get -v -t -d ./...
+
+    - name: Verify dependencies
+      run: go mod verify
+
+    - name: Run go vet
+      run: go vet ./...
+
+    - name: Run tests
+      run: go test -v -race -coverprofile=coverage.txt -covermode=atomic ./...
+
+    - name: Upload coverage to Codecov
+      uses: codecov/codecov-action@v3
+      with:
+        files: ./coverage.txt
+        fail_ci_if_error: false
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: ['1.20', '1.21']
+        os: [ubuntu-latest, macos-latest]
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v4
+      with:
+        go-version: ${{ matrix.go-version }}
+
+    - name: Build
+      run: go build -v ./cmd/proxy