refactor(migrator): non-standard codes

migrator/index.go

@@ -17,12 +17,12 @@ func (idx Index) Table() string {
 	return idx.TableName
 }
 
-// Name return the name  of the index.
+// Name return the name of the index.
 func (idx Index) Name() string {
 	return idx.NameValue
 }
 
-// Columns return the columns fo the index
+// Columns return the columns of the index
 func (idx Index) Columns() []string {
 	return idx.ColumnList
 }
@@ -37,7 +37,7 @@ func (idx Index) Unique() (unique bool, ok bool) {
 	return idx.UniqueValue.Bool, idx.UniqueValue.Valid
 }
 
-// Option return the optional attribute fo the index
+// Option return the optional attribute of the index
 func (idx Index) Option() string {
 	return idx.OptionValue
 }

migrator/migrator.go

@@ -113,7 +113,7 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 				return err
 			}
 		} else {
-			if err := m.RunWithValue(value, func(stmt *gorm.Statement) (errr error) {
+			if err := m.RunWithValue(value, func(stmt *gorm.Statement) error {
 				columnTypes, err := queryTx.Migrator().ColumnTypes(value)
 				if err != nil {
 					return err
@@ -123,7 +123,6 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 					parseCheckConstraints = stmt.Schema.ParseCheckConstraints()
 				)
 				for _, dbName := range stmt.Schema.DBNames {
-					field := stmt.Schema.FieldsByDBName[dbName]
 					var foundColumn gorm.ColumnType
 
 					for _, columnType := range columnTypes {
@@ -135,12 +134,15 @@ func (m Migrator) AutoMigrate(values ...interface{}) error {
 
 					if foundColumn == nil {
 						// not found, add column
-						if err := execTx.Migrator().AddColumn(value, dbName); err != nil {
+						if err = execTx.Migrator().AddColumn(value, dbName); err != nil {
+							return err
+						}
+					} else {
+						// found, smartly migrate
+						field := stmt.Schema.FieldsByDBName[dbName]
+						if err = execTx.Migrator().MigrateColumn(value, field, foundColumn); err != nil {
 							return err
 						}
-					} else if err := execTx.Migrator().MigrateColumn(value, field, foundColumn); err != nil {
-						// found, smart migrate
-						return err
 					}
 				}
 
@@ -195,7 +197,7 @@ func (m Migrator) GetTables() (tableList []string, err error) {
 func (m Migrator) CreateTable(values ...interface{}) error {
 	for _, value := range m.ReorderModels(values, false) {
 		tx := m.DB.Session(&gorm.Session{})
-		if err := m.RunWithValue(value, func(stmt *gorm.Statement) (errr error) {
+		if err := m.RunWithValue(value, func(stmt *gorm.Statement) (err error) {
 			var (
 				createTableSQL          = "CREATE TABLE ? ("
 				values                  = []interface{}{m.CurrentTable(stmt)}
@@ -214,7 +216,7 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 
 			if !hasPrimaryKeyInDataType && len(stmt.Schema.PrimaryFields) > 0 {
 				createTableSQL += "PRIMARY KEY ?,"
-				primaryKeys := []interface{}{}
+				primaryKeys := make([]interface{}, 0, len(stmt.Schema.PrimaryFields))
 				for _, field := range stmt.Schema.PrimaryFields {
 					primaryKeys = append(primaryKeys, clause.Column{Name: field.DBName})
 				}
@@ -225,8 +227,8 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 			for _, idx := range stmt.Schema.ParseIndexes() {
 				if m.CreateIndexAfterCreateTable {
 					defer func(value interface{}, name string) {
-						if errr == nil {
-							errr = tx.Migrator().CreateIndex(value, name)
+						if err == nil {
+							err = tx.Migrator().CreateIndex(value, name)
 						}
 					}(value, idx.Name)
 				} else {
@@ -276,8 +278,8 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 				createTableSQL += fmt.Sprint(tableOption)
 			}
 
-			errr = tx.Exec(createTableSQL, values...).Error
-			return errr
+			err = tx.Exec(createTableSQL, values...).Error
+			return err
 		}); err != nil {
 			return err
 		}
@@ -498,7 +500,7 @@ func (m Migrator) MigrateColumn(value interface{}, field *schema.Field, columnTy
 		currentDefaultNotNull := field.HasDefaultValue && (field.DefaultValueInterface != nil || !strings.EqualFold(field.DefaultValue, "NULL"))
 		dv, dvNotNull := columnType.DefaultValue()
 		if dvNotNull && !currentDefaultNotNull {
-			// defalut value -> null
+			// default value -> null
 			alterColumn = true
 		} else if !dvNotNull && currentDefaultNotNull {
 			// null -> default value