improve error in native.go

Signed-off-by: Adrian Moreno <[email protected]>

native.go

@@ -4,6 +4,22 @@ import (
 	"fmt"
 )
 
+// ErrNoTable describes a error in the provided table information
+type ErrNoTable struct {
+	table string
+}
+
+func (e *ErrNoTable) Error() string {
+	return fmt.Sprintf("Table not found: %s", e.table)
+}
+
+// NewErrNoTable creates a new ErrNoTable
+func NewErrNoTable(table string) error {
+	return &ErrNoTable{
+		table: table,
+	}
+}
+
 // NativeAPI is an API that offers functions to interact with libovsdb without
 // having to handle it's internal objects. It uses a DatabaseSchema to infer the
 // type of each value and make translations.
@@ -42,7 +58,7 @@ func (na NativeAPI) GetRowData(tableName string, row *Row) (map[string]interface
 func (na NativeAPI) GetData(tableName string, ovsData map[string]interface{}) (map[string]interface{}, error) {
 	table, ok := na.schema.Tables[tableName]
 	if !ok {
-		return nil, fmt.Errorf("TableName not found in schema %s", tableName)
+		return nil, NewErrNoTable(tableName)
 	}
 	nativeRow := make(map[string]interface{}, len(table.Columns))
 
@@ -66,12 +82,11 @@ func (na NativeAPI) GetData(tableName string, ovsData map[string]interface{}) (m
 func (na NativeAPI) NewRow(tableName string, data interface{}) (map[string]interface{}, error) {
 	table, ok := na.schema.Tables[tableName]
 	if !ok {
-		return nil, fmt.Errorf("TableName not found in schema %s", tableName)
+		return nil, NewErrNoTable(tableName)
 	}
-
 	nativeRow, ok := data.(map[string]interface{})
 	if !ok {
-		return nil, fmt.Errorf("NativeAPI.NewRow requires data to be *map[string]interface{}")
+		return nil, NewErrWrongType("NativeAPI.NewRow", "map[string]interface{}", data)
 	}
 
 	ovsRow := make(map[string]interface{}, len(table.Columns))
@@ -83,7 +98,7 @@ func (na NativeAPI) NewRow(tableName string, data interface{}) (map[string]inter
 		}
 		ovsElem, err := NativeToOvs(column, nativeElem)
 		if err != nil {
-			return nil, fmt.Errorf("Table %s, Column %s: Failed to generate OvS element: %s", tableName, name, err.Error())
+			return nil, fmt.Errorf("Table %s, Column %s: Failed to generate OvS element. %s", tableName, name, err.Error())
 		}
 		ovsRow[name] = ovsElem
 	}