Merge pull request #78 from ulule/fix/do-not-panic-when-formatting-a-…

…nil-valuer

fix: don't panic when formatting a nil valuer

builder/insert_test.go

@@ -2,6 +2,7 @@ package builder_test
 
 import (
 	"database/sql"
+	"database/sql/driver"
 	"fmt"
 	"testing"
 	"time"
@@ -495,9 +496,29 @@ func TestInsert_Valuer(t *testing.T) {
 			NamedQuery: "INSERT INTO table (email, login) VALUES (:arg_1, :arg_2)",
 			Args:       []interface{}{"[email protected]", sql.NullInt64{}},
 		},
+		{
+			Name: "nil valuer",
+			Builder: loukoum.
+				Insert("table").
+				Columns("email", "login").
+				Values("[email protected]", (*valuer)(nil)),
+			String:     "INSERT INTO table (email, login) VALUES ('[email protected]', NULL)",
+			Query:      "INSERT INTO table (email, login) VALUES ($1, $2)",
+			NamedQuery: "INSERT INTO table (email, login) VALUES (:arg_1, :arg_2)",
+			Args:       []interface{}{"[email protected]", (*valuer)(nil)},
+		},
 	})
 }
 
+type valuer struct{}
+
+func (valuer) Value() (driver.Value, error) {
+	return nil, nil
+}
+func (*valuer) Scan(src interface{}) error {
+	return nil
+}
+
 func TestInsert_Set(t *testing.T) {
 	RunBuilderTests(t, []BuilderTest{
 		{

format/format.go

@@ -5,6 +5,7 @@ import (
 	"database/sql/driver"
 	"encoding/hex"
 	"fmt"
+	"reflect"
 	"strconv"
 	"time"
 )
@@ -23,6 +24,12 @@ func Value(arg interface{}) string { // nolint: gocyclo
 	case time.Time:
 		return Time(value)
 	case driver.Valuer:
+		reflectvalue := reflect.ValueOf(value)
+		if reflectvalue.Kind() == reflect.Ptr &&
+			reflectvalue.IsNil() {
+			return "NULL"
+		}
+
 		v, err := value.Value()
 		if err != nil {
 			panic("loukoum: was not able to retrieve valuer value")