From 2202e99cbf0f43c35315fe4d17b87ac81f0f2d23 Mon Sep 17 00:00:00 2001
From: s-takehana <s-takehana@users.noreply.github.com>
Date: Sun, 18 Jul 2021 12:47:44 +0900
Subject: [PATCH] Fix create index with comments in MySQL (#4521)

* Fix create index with comments in MySQL

* Fix tests
---
 migrator/migrator.go  |  8 ++++++++
 tests/migrate_test.go | 29 ++++++++++++++++++++++++-----
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/migrator/migrator.go b/migrator/migrator.go
index 03ffdd02..7c7405b3 100644
--- a/migrator/migrator.go
+++ b/migrator/migrator.go
@@ -195,6 +195,10 @@ func (m Migrator) CreateTable(values ...interface{}) error {
 					}
 					createTableSQL += "INDEX ? ?"
 
+					if idx.Comment != "" {
+						createTableSQL += fmt.Sprintf(" COMMENT '%s'", idx.Comment)
+					}
+
 					if idx.Option != "" {
 						createTableSQL += " " + idx.Option
 					}
@@ -601,6 +605,10 @@ func (m Migrator) CreateIndex(value interface{}, name string) error {
 				createIndexSQL += " USING " + idx.Type
 			}
 
+			if idx.Comment != "" {
+				createIndexSQL += fmt.Sprintf(" COMMENT '%s'", idx.Comment)
+			}
+
 			if idx.Option != "" {
 				createIndexSQL += " " + idx.Option
 			}
diff --git a/tests/migrate_test.go b/tests/migrate_test.go
index 4da3856f..599ca850 100644
--- a/tests/migrate_test.go
+++ b/tests/migrate_test.go
@@ -142,17 +142,36 @@ func TestSmartMigrateColumn(t *testing.T) {
 
 }
 
-func TestMigrateWithComment(t *testing.T) {
-	type UserWithComment struct {
+func TestMigrateWithColumnComment(t *testing.T) {
+	type UserWithColumnComment struct {
 		gorm.Model
-		Name string `gorm:"size:111;index:,comment:这是一个index;comment:this is a 字段"`
+		Name string `gorm:"size:111;comment:this is a 字段"`
 	}
 
-	if err := DB.Migrator().DropTable(&UserWithComment{}); err != nil {
+	if err := DB.Migrator().DropTable(&UserWithColumnComment{}); err != nil {
 		t.Fatalf("Failed to drop table, got error %v", err)
 	}
 
-	if err := DB.AutoMigrate(&UserWithComment{}); err != nil {
+	if err := DB.AutoMigrate(&UserWithColumnComment{}); err != nil {
+		t.Fatalf("Failed to auto migrate, but got error %v", err)
+	}
+}
+
+func TestMigrateWithIndexComment(t *testing.T) {
+	if DB.Dialector.Name() != "mysql" {
+		t.Skip()
+	}
+
+	type UserWithIndexComment struct {
+		gorm.Model
+		Name string `gorm:"size:111;index:,comment:这是一个index"`
+	}
+
+	if err := DB.Migrator().DropTable(&UserWithIndexComment{}); err != nil {
+		t.Fatalf("Failed to drop table, got error %v", err)
+	}
+
+	if err := DB.AutoMigrate(&UserWithIndexComment{}); err != nil {
 		t.Fatalf("Failed to auto migrate, but got error %v", err)
 	}
 }