♻ refactor: improve error handling

Author: nmdra

api/handlers.go

@@ -17,11 +17,18 @@ type AddBookRequest struct {
 }
 
 func (h *BookHandler) AddBook(c echo.Context) error {
+	ctx := c.Request().Context()
 	var req AddBookRequest
 	if err := c.Bind(&req); err != nil {
 		return c.JSON(http.StatusBadRequest, echo.Map{"error": "invalid request"})
 	}
 
+	select {
+	case <-ctx.Done():
+		return c.JSON(http.StatusRequestTimeout, echo.Map{"error": "request canceled or timed out"})
+	default:
+	}
+
 	err := h.Service.AddBook(c.Request().Context(), req.Title, req.Description)
 	if err != nil {
 		return c.JSON(http.StatusInternalServerError, echo.Map{"error": err.Error()})
@@ -53,5 +60,3 @@ func (h *BookHandler) SearchBooks(c echo.Context) error {
 
 	return c.JSON(http.StatusOK, results)
 }
-
-// TODO: add redis cache

cmd/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"flag"
 	"fmt"
 	"log/slog"
@@ -16,7 +17,7 @@ import (
 	"semantic-search/internal/repository"
 	"semantic-search/internal/service"
 
-	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/jackc/pgx/v5/pgconn"
 	"github.com/labstack/echo/v4"
 	"github.com/labstack/echo/v4/middleware"
 	"github.com/lmittmann/tint"
@@ -53,11 +54,12 @@ func main() {
 
 	ctx := context.Background()
 
-	dbpool, err := connectToPostgres(ctx, cfg, logger)
+	dbpool, err := db.NewPool(ctx, cfg.db.dsn, logger)
 	if err != nil {
 		logger.Error("Database connection failed", "error", err)
 		os.Exit(1)
 	}
+	logger.Info("Connected to PostgreSQL")
 	defer dbpool.Close()
 
 	embedder, err := newEmbedder(ctx, cfg, logger)
@@ -186,20 +188,23 @@ func setupLogger(levelStr string) *slog.Logger {
 }
 
 func runMigrations(cfg config, logger *slog.Logger) error {
-	if err := db.RunMigrations(cfg.db.dsn, logger); err != nil {
-		return err
+	err := db.RunMigrations(cfg.db.dsn, logger)
+	if err == nil {
+		logger.Info("Migrations applied successfully")
+		return nil
 	}
-	logger.Info("Migrations applied successfully")
-	return nil
-}
 
-func connectToPostgres(ctx context.Context, cfg config, logger *slog.Logger) (*pgxpool.Pool, error) {
-	dbpool, err := db.NewPool(ctx, cfg.db.dsn, logger)
-	if err != nil {
-		return nil, err
+	var pgErr *pgconn.PgError
+	if errors.As(err, &pgErr) {
+		logger.Error("Postgres error during migration",
+			"code", pgErr.Code,
+			"message", pgErr.Message,
+			"detail", pgErr.Detail,
+			"where", pgErr.Where,
+		)
 	}
-	logger.Info("Connected to PostgreSQL")
-	return dbpool, nil
+
+	return fmt.Errorf("failed to run migrations: %w", err)
 }
 
 func newEmbedder(ctx context.Context, cfg config, logger *slog.Logger) (embed.Embedder, error) {

internal/db/db.go

@@ -11,7 +11,6 @@ import (
 
 func NewPool(ctx context.Context, dsn string, logger *slog.Logger) (*pgxpool.Pool, error) {
 	if dsn == "" {
-		logger.Error("DSN is not set")
 		return nil, fmt.Errorf("DSN is not set")
 	}
 
@@ -20,13 +19,11 @@ func NewPool(ctx context.Context, dsn string, logger *slog.Logger) (*pgxpool.Poo
 
 	config, err := pgxpool.ParseConfig(dsn)
 	if err != nil {
-		logger.Error("Failed to parse DSN", "error", err)
 		return nil, fmt.Errorf("failed to parse DSN: %w", err)
 	}
 
 	pool, err := pgxpool.NewWithConfig(ctx, config)
 	if err != nil {
-		logger.Error("Failed to create DB pool", "error", err)
 		return nil, fmt.Errorf("failed to create pool: %w", err)
 	}
 
@@ -45,7 +42,6 @@ func NewPool(ctx context.Context, dsn string, logger *slog.Logger) (*pgxpool.Poo
 	`).Scan(&exists)
 
 	if err != nil {
-		logger.Error("Failed to check books table existence", "error", err)
 		return nil, fmt.Errorf("failed to check books table: %w", err)
 	}
 

internal/db/migrate.go

@@ -22,7 +22,7 @@ func RunMigrations(dsn string, logger *slog.Logger) error {
 
 	defer func() {
 		if err := db.Close(); err != nil {
-			logger.Error("error closing DB: %v", "error", err)
+			logger.Error("error closing DB: %w", "error", err)
 		}
 	}()