feat: add encode/decode helper functions

internal/db/migrations/20241104191906_create_users_table.sql

@@ -7,8 +7,8 @@ create table users
 
     created_at timestamptz not null default current_timestamp,
     updated_at timestamptz not null default current_timestamp,
+    email      text        not null check (char_length(email) < 255) unique,
 
-    email      text        not null check (char_length(email) < 255),
     -- bcrypt hash is always 60
     password   text        not null check (char_length(password) = 60),
 

internal/server/handlers.go

@@ -26,28 +26,31 @@ func (s *Server) HandleHealthCheck(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) HandleCreateUser(w http.ResponseWriter, r *http.Request) {
-	var req struct {
-		Email    string `json:"email"`
-		Password string `json:"password"`
-	}
-	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+	// Decode the request body into a CreateUserParams struct
+	userParams, err := decode[db.CreateUserParams](r)
+	if err != nil {
 		http.Error(w, err.Error(), http.StatusBadRequest)
 		return
 	}
-	// TODO:
-	// - validate the request body and use proper status codes, e.g., malformed request body, etc.
-	// - hash the password
 
-	params := db.CreateUserParams(req)
-	user, err := s.client.Queries.CreateUser(r.Context(), params)
+	// Create the user
+	user, err := s.client.Queries.CreateUser(r.Context(), userParams)
 	if err != nil {
 		// Return an unknown error
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
 
-	w.WriteHeader(http.StatusCreated)
-	err = json.NewEncoder(w).Encode(user)
+	// We use a custom response so we don't leak the password hash
+	res := struct {
+		Id  int64 `json:"id"`
+		msg string
+	}{
+		Id:  user.ID,
+		msg: "User created successfully",
+	}
+
+	err = encode(w, r, http.StatusCreated, res)
 	if err != nil {
 		return
 	}

internal/server/utils.go

@@ -0,0 +1,28 @@
+package server
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+func encode[T any](w http.ResponseWriter, r *http.Request, status int, v T) error {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+
+	if err := json.NewEncoder(w).Encode(v); err != nil {
+		return fmt.Errorf("encode json: %w", err)
+	}
+
+	return nil
+}
+
+func decode[T any](r *http.Request) (T, error) {
+	var v T
+
+	if err := json.NewDecoder(r.Body).Decode(&v); err != nil {
+		return v, fmt.Errorf("decode json: %w", err)
+	}
+
+	return v, nil
+}