refactored the enum mirator to also be simpler to maintain

server/backend/migration/safe_enum_migrate.go

@@ -5,32 +5,27 @@ import (
 	"fmt"
 	"strings"
 
+	log "github.com/sirupsen/logrus"
+
 	"gorm.io/gorm"
 )
 
 func SafeEnumAdd(tx *gorm.DB, table interface{}, column string, additionalTypes ...string) error {
 	enumTypes, err := getEnumTypesFromDB(tx, table, column)
-
 	if err != nil {
 		return err
 	}
 
-	enumTypes = append(enumTypes, additionalTypes...)
-	enumTypes = ensureUnique(enumTypes)
-
-	return alterEnumColumn(tx, table, column, enumTypes)
+	return alterEnumColumn(tx, table, column, ensureUnique(append(enumTypes, additionalTypes...)))
 }
 
 func SafeEnumRemove(tx *gorm.DB, table interface{}, column string, rollbackTypes ...string) error {
 	enumTypes, err := getEnumTypesFromDB(tx, table, column)
-
 	if err != nil {
 		return err
 	}
 
-	enumTypes = RemoveTypes(enumTypes, rollbackTypes...)
-
-	return alterEnumColumn(tx, table, column, enumTypes)
+	return alterEnumColumn(tx, table, column, RemoveTypes(enumTypes, rollbackTypes...))
 }
 
 func ensureUnique(types []string) []string {
@@ -46,44 +41,34 @@ func ensureUnique(types []string) []string {
 }
 
 func alterEnumColumn(tx *gorm.DB, table interface{}, column string, types []string) error {
-	enum := BuildEnum(types)
-
 	stmt := &gorm.Statement{DB: tx}
 	err := stmt.Parse(&table)
 	if err != nil {
 		return errors.New("could not parse enum table")
 	}
-	tableName := stmt.Schema.Table
 
-	rawQuery := fmt.Sprintf(
+	if err := tx.Exec(fmt.Sprintf(
 		"ALTER TABLE %s MODIFY %s %s;",
-		tableName,
+		stmt.Schema.Table,
 		column,
-		enum,
-	)
-
-	tx = tx.Exec(rawQuery)
-
-	if tx.Error != nil {
+		BuildEnum(types),
+	)).Error; err != nil {
+		log.WithError(err).Error("Error altering enum table")
 		return errors.New("could not alter enum table")
 	}
-
 	return nil
 }
 
 func getEnumTypesFromDB(tx *gorm.DB, table interface{}, column string) ([]string, error) {
 	columnType, err := tx.Migrator().ColumnTypes(&table)
-
 	if err != nil {
 		return nil, errors.New("could not get enum column types")
 	}
 
 	enumTypes, err := getEnumTypes(columnType, column)
-
 	if err != nil {
 		return nil, err
 	}
-
 	return enumTypes, nil
 }
 
@@ -100,20 +85,16 @@ func RemoveTypes(types []string, rollbackTypes ...string) []string {
 }
 
 func getEnumTypes(columTypes []gorm.ColumnType, column string) ([]string, error) {
-	var cType string
-
 	for _, t := range columTypes {
 		if t.Name() == column {
 			if t, ok := t.ColumnType(); ok {
-				cType = t
-				break
+				return EnumTypesFromString(t)
 			} else {
 				return nil, errors.New("could not get column type")
 			}
 		}
 	}
-
-	return EnumTypesFromString(cType)
+	return nil, errors.New("column does not exist")
 }
 
 func EnumTypesFromString(enum string) ([]string, error) {
@@ -138,15 +119,6 @@ func EnumTypesFromString(enum string) ([]string, error) {
 }
 
 func BuildEnum(types []string) string {
-	str := "enum("
-
-	for _, t := range types {
-		str += fmt.Sprintf("'%s',", t)
-	}
-
-	str = strings.TrimRight(str, ",")
-
-	str += ")"
-
-	return str
+	enums := strings.Join(types, "','")
+	return fmt.Sprintf("enum('%s')", enums)
 }