Ginkgo Testing

Ginkgo is a BDD-style testing framework for Go, primarily used for E2E tests.

E2E Test Structure

test/e2e/
├── suite_test.go    # Suite bootstrap with BeforeSuite/AfterSuite
└── xxx_test.go      # Test specs

Suite Bootstrap

package e2e_test

import (
    "testing"

    . "github.com/onsi/ginkgo/v2"
    . "github.com/onsi/gomega"
)

var BaseURL string

func TestE2E(t *testing.T) {
    RegisterFailHandler(Fail)
    RunSpecs(t, "E2E Suite")
}

var _ = BeforeSuite(func() {
    // Setup: deploy app, initialize clients
    BaseURL = "http://localhost:8080"
})

var _ = AfterSuite(func() {
    // Cleanup resources
})

Test Specs

package e2e_test

import (
    "net/http"

    . "github.com/onsi/ginkgo/v2"
    . "github.com/onsi/gomega"
)

var _ = Describe("Health API", func() {
    var client *http.Client

    BeforeEach(func() {
        client = &http.Client{}
    })

    Describe("GET /api/v1/health", func() {
        Context("when server is running", func() {
            It("should return status ok", func() {
                resp, err := client.Get(BaseURL + "/api/v1/health")
                Expect(err).NotTo(HaveOccurred())
                defer resp.Body.Close()

                Expect(resp.StatusCode).To(Equal(http.StatusOK))
            })
        })
    })
})

Common Matchers

// Equality
Expect(actual).To(Equal(expected))

// Errors
Expect(err).NotTo(HaveOccurred())
Expect(err).To(MatchError("message"))

// Collections
Expect(slice).To(HaveLen(3))
Expect(slice).To(ContainElement("foo"))

// Strings
Expect(str).To(ContainSubstring("partial"))

// Numbers
Expect(n).To(BeNumerically(">", 10))

// Async (for eventual consistency)
Eventually(func() int { return getCount() }).Should(Equal(5))

Best Practices

1. Use BeforeSuite/AfterSuite for app deployment and cleanup
2. Use BeforeEach for per-test setup (e.g., HTTP client)
3. Use Context for different scenarios
4. Use By() to document test steps
5. Use Skip() when preconditions not met

Running E2E Tests

# Run E2E tests
ginkgo ./test/e2e/...

# Verbose output
ginkgo -v ./test/e2e/...

# Focus on specific specs
ginkgo --focus="Health" ./test/e2e/...