CodeBench: kompaktoitu Go handlers.go golden — error handling yhdelle riville

This commit is contained in:
2026-04-14 21:15:57 +03:00
parent 5b8919ef89
commit 7d49d62f81

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@@ -71,7 +71,7 @@ type UpdateTodo struct {
## handlers.go
CRUD handlers as closures taking *sql.DB. INSERT/UPDATE use RETURNING, sql.ErrNoRows for 404.
CRUD handlers as closures taking *sql.DB. Key patterns: INSERT RETURNING, sql.ErrNoRows for 404, RowsAffected for delete.
```go
package main
@@ -81,67 +81,51 @@ import (
"encoding/json"
"net/http"
"strconv"
"github.com/go-chi/chi/v5"
)
// POST — decode JSON, defaults with nil-check, INSERT RETURNING, StatusCreated.
func createTodo(db *sql.DB) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
var input CreateTodo
if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
http.Error(w, err.Error(), http.StatusBadRequest); return
}
priority := int64(1)
if input.Priority != nil {
priority = *input.Priority
}
if input.Priority != nil { priority = *input.Priority }
status := "pending"
if input.Status != nil {
status = *input.Status
}
if input.Status != nil { status = *input.Status }
var todo Todo
err := db.QueryRow(
`INSERT INTO todos (title, description, due_date, priority, status)
VALUES (?, ?, ?, ?, ?)
RETURNING id, title, description, due_date, priority, status`,
VALUES (?, ?, ?, ?, ?) RETURNING id, title, description, due_date, priority, status`,
input.Title, input.Description, input.DueDate, priority, status,
).Scan(&todo.ID, &todo.Title, &todo.Description, &todo.DueDate, &todo.Priority, &todo.Status)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError); return }
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusCreated)
json.NewEncoder(w).Encode(todo)
}
}
// GET list — db.Query + rows.Scan loop, empty slice not nil.
func listTodos(db *sql.DB) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
rows, err := db.Query("SELECT id, title, description, due_date, priority, status FROM todos")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError); return }
defer rows.Close()
var todos []Todo
todos := []Todo{}
for rows.Next() {
var t Todo
if err := rows.Scan(&t.ID, &t.Title, &t.Description, &t.DueDate, &t.Priority, &t.Status); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
rows.Scan(&t.ID, &t.Title, &t.Description, &t.DueDate, &t.Priority, &t.Status)
todos = append(todos, t)
}
if todos == nil {
todos = []Todo{}
}
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(todos)
}
}
// GET by id — QueryRow + sql.ErrNoRows → 404.
func getTodo(db *sql.DB) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
id, _ := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
@@ -149,83 +133,51 @@ func getTodo(db *sql.DB) http.HandlerFunc {
err := db.QueryRow(
"SELECT id, title, description, due_date, priority, status FROM todos WHERE id = ?", id,
).Scan(&todo.ID, &todo.Title, &todo.Description, &todo.DueDate, &todo.Priority, &todo.Status)
if err == sql.ErrNoRows {
http.Error(w, "not found", http.StatusNotFound)
return
}
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err == sql.ErrNoRows { http.Error(w, "not found", http.StatusNotFound); return }
if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError); return }
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(todo)
}
}
// PUT — fetch existing, merge with input nil-checks, UPDATE RETURNING.
func updateTodo(db *sql.DB) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
id, _ := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
var existing Todo
err := db.QueryRow(
"SELECT id, title, description, due_date, priority, status FROM todos WHERE id = ?", id,
err := db.QueryRow("SELECT id, title, description, due_date, priority, status FROM todos WHERE id = ?", id,
).Scan(&existing.ID, &existing.Title, &existing.Description, &existing.DueDate, &existing.Priority, &existing.Status)
if err == sql.ErrNoRows {
http.Error(w, "not found", http.StatusNotFound)
return
}
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err == sql.ErrNoRows { http.Error(w, "not found", http.StatusNotFound); return }
if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError); return }
var input UpdateTodo
if err := json.NewDecoder(r.Body).Decode(&input); err != nil {
http.Error(w, err.Error(), http.StatusBadRequest)
return
}
if input.Title != nil {
existing.Title = *input.Title
}
if input.Description != nil {
existing.Description = input.Description
}
if input.DueDate != nil {
existing.DueDate = input.DueDate
}
if input.Priority != nil {
existing.Priority = *input.Priority
}
if input.Status != nil {
existing.Status = *input.Status
http.Error(w, err.Error(), http.StatusBadRequest); return
}
if input.Title != nil { existing.Title = *input.Title }
if input.Description != nil { existing.Description = input.Description }
if input.DueDate != nil { existing.DueDate = input.DueDate }
if input.Priority != nil { existing.Priority = *input.Priority }
if input.Status != nil { existing.Status = *input.Status }
var updated Todo
err = db.QueryRow(
`UPDATE todos SET title = ?, description = ?, due_date = ?, priority = ?, status = ?
WHERE id = ?
`UPDATE todos SET title=?, description=?, due_date=?, priority=?, status=? WHERE id=?
RETURNING id, title, description, due_date, priority, status`,
existing.Title, existing.Description, existing.DueDate, existing.Priority, existing.Status, id,
).Scan(&updated.ID, &updated.Title, &updated.Description, &updated.DueDate, &updated.Priority, &updated.Status)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError); return }
w.Header().Set("Content-Type", "application/json")
json.NewEncoder(w).Encode(updated)
}
}
// DELETE — Exec + RowsAffected == 0 → 404, else 204.
func deleteTodo(db *sql.DB) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
id, _ := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
result, err := db.Exec("DELETE FROM todos WHERE id = ?", id)
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError); return }
rows, _ := result.RowsAffected()
if rows == 0 {
http.Error(w, "not found", http.StatusNotFound)
return
}
if rows == 0 { http.Error(w, "not found", http.StatusNotFound); return }
w.WriteHeader(http.StatusNoContent)
}
}