feat: initial commit

internal/setup/helper.go

@@ -0,0 +1,34 @@
+package setup
+
+import (
+	"context"
+	"sync"
+
+	"forge.cadoles.com/wpetit/kouiz/internal/config"
+	"github.com/pkg/errors"
+)
+
+func createFromConfigOnce[T any](factory func(ctx context.Context, conf *config.Config) (T, error)) func(ctx context.Context, conf *config.Config) (T, error) {
+	var (
+		once    sync.Once
+		service T
+		onceErr error
+	)
+
+	return func(ctx context.Context, conf *config.Config) (T, error) {
+		once.Do(func() {
+			srv, err := factory(ctx, conf)
+			if err != nil {
+				onceErr = errors.WithStack(err)
+				return
+			}
+
+			service = srv
+		})
+		if onceErr != nil {
+			return *new(T), onceErr
+		}
+
+		return service, nil
+	}
+}