support for usage of sql.Out as a param value

go.mod

@@ -1 +1,3 @@
 module github.com/DATA-DOG/go-sqlmock
+
+go 1.12

sqlmock_go18.go

@@ -114,8 +114,3 @@ func (stmt *statement) QueryContext(ctx context.Context, args []driver.NamedValu
 
 // @TODO maybe add ExpectedBegin.WithOptions(driver.TxOptions)
 
-// CheckNamedValue meets https://golang.org/pkg/database/sql/driver/#NamedValueChecker
-func (c *sqlmock) CheckNamedValue(nv *driver.NamedValue) (err error) {
-	nv.Value, err = c.converter.ConvertValue(nv.Value)
-	return err
-}

sqlmock_go18_19.go

@@ -0,0 +1,11 @@
+// +build go1.8,!go1.9
+
+package sqlmock
+
+import "database/sql/driver"
+
+// CheckNamedValue meets https://golang.org/pkg/database/sql/driver/#NamedValueChecker
+func (c *sqlmock) CheckNamedValue(nv *driver.NamedValue) (err error) {
+	nv.Value, err = c.converter.ConvertValue(nv.Value)
+	return err
+}

sqlmock_go19.go

@@ -0,0 +1,19 @@
+// +build go1.9
+
+package sqlmock
+
+import (
+	"database/sql"
+	"database/sql/driver"
+)
+
+// CheckNamedValue meets https://golang.org/pkg/database/sql/driver/#NamedValueChecker
+func (c *sqlmock) CheckNamedValue(nv *driver.NamedValue) (err error) {
+	switch nv.Value.(type) {
+	case sql.Out:
+		return nil
+	default:
+		nv.Value, err = c.converter.ConvertValue(nv.Value)
+		return err
+	}
+}