ci: add GitHub Actions workflow for tests and linting

.github/workflows/ci.yml

@@ -0,0 +1,54 @@
+name: CI
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Run Tests
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        go-version: [ "1.21.x", "1.22.x", "1.23.x", "1.24.x", "1.25.x", "1.26.x"]
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Go ${{ matrix.go-version }}
+      uses: actions/setup-go@v5
+      with:
+        go-version: ${{ matrix.go-version }}
+
+    - name: Verify dependencies
+      run: go mod verify
+
+    - name: Build
+      run: go build -v ./...
+
+    - name: Run tests with race detector
+      run: go test -v -race -coverprofile=coverage.txt -covermode=atomic ./...
+
+  lint:
+    name: Lint Code
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Go
+      uses: actions/setup-go@v5
+      with:
+        go-version: "1.21.x"
+        cache: false # golangci-lint-action handles its own caching
+
+    - name: golangci-lint
+      uses: golangci/golangci-lint-action@v6
+      with:
+        version: latest
+        args: --timeout=5m

README.md

@@ -60,7 +60,7 @@ func main() {
 
 	// 2. Worker reuse is disabled to prevent state leaks between sessions
 	pool, _ := herd.New(factory,
-		herd.WithAutoScale(1, 5),
+		herd.WithAutoScale(1, 5), // auto-scale between 1 and 5 concurrent tenants (until expires)
 		herd.WithTTL(15 * time.Minute),
 		herd.WithWorkerReuse(false), // CRITICAL: Never share browsers between users
 	)

pool.go

@@ -136,7 +136,6 @@ type Pool[C any] struct {
 	workers   []Worker[C]    // all known workers (for Stats / Shutdown)
 	available chan Worker[C] // free workers
 
-	wg   sync.WaitGroup
 	done chan struct{} // closed when the pool is shutting down, all the background loops will listen for this
 
 	// pool context for canceling all the background loops