everybody loves a refactor

internal/db/errors.go

@@ -0,0 +1,31 @@
+package db
+
+import (
+	"fmt"
+	"strings"
+)
+
+func IsBadRequest(err error) bool {
+	return strings.HasPrefix(err.Error(), "bad request:")
+}
+
+func BadRequest(err string) error {
+	return fmt.Errorf("bad request: %s", err)
+}
+
+func BadRequestNotFound(resource, field string, value any) error {
+	errStr := fmt.Sprintf("%s with %s=%v not found", resource, field, value)
+	return BadRequest(errStr)
+}
+
+func BadRequestNotAssociated(parent, child string, parentID, childID any) error {
+	errStr := fmt.Sprintf("%s (ID: %v) not associated with %s (ID: %v)",
+		child, childID, parent, parentID)
+	return BadRequest(errStr)
+}
+
+func BadRequestAssociated(parent, child string, parentID, childID any) error {
+	errStr := fmt.Sprintf("%s (ID: %v) already associated with %s (ID: %v)",
+		child, childID, parent, parentID)
+	return BadRequest(errStr)
+}