Golang中如何使用httptest.NewRequest包含带值的路径？

在测试HTTP处理器时，httptest.NewRequest创建的请求不会自动解析路径参数。你需要手动设置路径值，或者使用路由器来解析。以下是两种解决方案：

方案1：手动设置路径值（推荐用于单元测试）

在测试中直接设置PathValue：

email := "myemail@test.me"

request := httptest.NewRequest(http.MethodPost, "/users/"+email, nil)
// 手动设置路径参数
request.SetPathValue("email", email)

response := httptest.NewRecorder()
handleEmailCheck(response, request)

方案2：使用路由器进行测试（集成测试）

如果你需要测试完整的路由解析，应该使用路由器：

email := "myemail@test.me"

router := http.NewServeMux()
router.HandleFunc("POST /users/{email}", handleEmailCheck)

request := httptest.NewRequest(http.MethodPost, "/users/"+email, nil)
response := httptest.NewRecorder()

router.ServeHTTP(response, request)

完整示例代码

func TestHandleEmailCheck(t *testing.T) {
    email := "myemail@test.me"
    
    // 方案1：直接设置路径值
    t.Run("unit test with manual path value", func(t *testing.T) {
        request := httptest.NewRequest(http.MethodPost, "/users/"+email, nil)
        request.SetPathValue("email", email)
        
        response := httptest.NewRecorder()
        handleEmailCheck(response, request)
        
        if response.Code != http.StatusOK {
            t.Errorf("expected status OK, got %v", response.Code)
        }
    })
    
    // 方案2：使用路由器
    t.Run("integration test with router", func(t *testing.T) {
        router := http.NewServeMux()
        router.HandleFunc("POST /users/{email}", handleEmailCheck)
        
        request := httptest.NewRequest(http.MethodPost, "/users/"+email, nil)
        response := httptest.NewRecorder()
        
        router.ServeHTTP(response, request)
        
        if response.Code != http.StatusOK {
            t.Errorf("expected status OK, got %v", response.Code)
        }
    })
}

处理器示例

func handleEmailCheck(w http.ResponseWriter, r *http.Request) {
    email := r.PathValue("email")
    if email == "" {
        http.Error(w, "email parameter required", http.StatusBadRequest)
        return
    }
    
    // 处理逻辑
    fmt.Fprintf(w, "Processing email: %s", email)
}

使用SetPathValue方法是Go 1.22+中引入的，专门用于在测试中模拟路径参数。对于单元测试处理器逻辑，这是最直接的方法。