// Package models contains standard library HTTP handler patterns
// This file tests stdlib http.HandleFunc() and http.Handle() detection
package models
import (
"encoding/json"
"fmt"
"net/http"
)
// User for response examples
type UserData struct {
ID int64 `json:"id"`
Name string `json:"name"`
Email string `json:"email"`
}
// Simple handler using http.HandleFunc with anonymous function
func SetupBasicRoutes() {
// Basic GET handler with anonymous function
http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello, World!"))
})
// Health check endpoint
http.HandleFunc("/health", func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
json.NewEncoder(w).Encode(map[string]string{"status": "ok"})
})
// User list endpoint
http.HandleFunc("/users", handleUsers)
// Single user endpoint
http.HandleFunc("/users/", handleUser)
// API versioned endpoint
http.HandleFunc("/api/v1/status", func(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode(map[string]string{
"version": "1.0.0",
"status": "running",
})
})
}
// Named handler function for users
func handleUsers(w http.ResponseWriter, r *http.Request) {
switch r.Method {
case http.MethodGet:
users := []UserData{
{ID: 1, Name: "Alice", Email: "alice@example.com"},
{ID: 2, Name: "Bob", Email: "bob@example.com"},
}
json.NewEncoder(w).Encode(users)
case http.MethodPost:
var user UserData
json.NewDecoder(r.Body).Decode(&user)
user.ID = 3
w.WriteHeader(http.StatusCreated)
json.NewEncoder(w).Encode(user)
default:
w.WriteHeader(http.StatusMethodNotAllowed)
}
}
// Named handler function for single user
func handleUser(w http.ResponseWriter, r *http.Request) {
// Parse user ID from path
id := r.URL.Path[len("/users/"):]
switch r.Method {
case http.MethodGet:
user := UserData{ID: 1, Name: "Alice", Email: "alice@example.com"}
json.NewEncoder(w).Encode(user)
case http.MethodPut:
var user UserData
json.NewDecoder(r.Body).Decode(&user)
json.NewEncoder(w).Encode(user)
case http.MethodDelete:
w.WriteHeader(http.StatusNoContent)
default:
w.WriteHeader(http.StatusMethodNotAllowed)
}
_ = id // Suppress unused warning
}
// Using http.ServeMux explicitly
func SetupMuxRoutes() *http.ServeMux {
mux := http.NewServeMux()
// Register handlers on the mux
mux.HandleFunc("/", homeHandler)
mux.HandleFunc("/about", aboutHandler)
mux.HandleFunc("/contact", contactHandler)
mux.HandleFunc("/api/items", itemsHandler)
mux.HandleFunc("/api/items/", itemHandler)
return mux
}
func homeHandler(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Home Page")
}
func aboutHandler(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "About Page")
}
func contactHandler(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Contact Page")
}
func itemsHandler(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode([]string{"item1", "item2", "item3"})
}
func itemHandler(w http.ResponseWriter, r *http.Request) {
id := r.URL.Path[len("/api/items/"):]
json.NewEncoder(w).Encode(map[string]string{"id": id})
}
// Using http.Handle with a handler type
type healthHandler struct{}
func (h *healthHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode(map[string]string{"status": "healthy"})
}
type metricsHandler struct{}
func (m *metricsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain")
fmt.Fprintf(w, "# HELP requests_total Total requests\n")
fmt.Fprintf(w, "requests_total 100\n")
}
func SetupHandlerTypes() {
// Using http.Handle with custom handler types
http.Handle("/healthz", &healthHandler{})
http.Handle("/metrics", &metricsHandler{})
// Using http.Handle with http.HandlerFunc adapter
http.Handle("/ready", http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusOK)
}))
}
// Server struct with method handlers
type APIServer struct {
mux *http.ServeMux
}
func NewAPIServer() *APIServer {
s := &APIServer{
mux: http.NewServeMux(),
}
s.setupRoutes()
return s
}
func (s *APIServer) setupRoutes() {
s.mux.HandleFunc("/api/users", s.handleUsersEndpoint)
s.mux.HandleFunc("/api/products", s.handleProductsEndpoint)
s.mux.HandleFunc("/api/orders", s.handleOrdersEndpoint)
}
func (s *APIServer) handleUsersEndpoint(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode([]string{"user1", "user2"})
}
func (s *APIServer) handleProductsEndpoint(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode([]string{"product1", "product2"})
}
func (s *APIServer) handleOrdersEndpoint(w http.ResponseWriter, r *http.Request) {
json.NewEncoder(w).Encode([]string{"order1", "order2"})
}
func (s *APIServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
s.mux.ServeHTTP(w, r)
}
// Multiple paths registered in a loop (harder to detect)
func SetupLoopRoutes() {
paths := []string{"/path1", "/path2", "/path3"}
for _, p := range paths {
path := p // Capture for closure
http.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
fmt.Fprintf(w, "Path: %s", path)
})
}
}
// FileServer example
func SetupFileServer() {
// Static file serving
http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./static"))))
// Single file serving
http.HandleFunc("/favicon.ico", func(w http.ResponseWriter, r *http.Request) {
http.ServeFile(w, r, "./static/favicon.ico")
})
}
