feat: null_safety test

tests/models/testdata.go

@@ -0,0 +1,26 @@
+package models
+
+type Order struct {
+	Id            uint `gorm:"primaryKey"`
+	Status        string
+	ProductTypeId uint
+	ProductType   ProductType
+	ProductAmount uint
+	Description   string
+	CustomerId    uint `gorm:"null;foreignKey:CustomerId;"` // want "Null safety error in \"Order\" model, field \"CustomerId\": column nullable policy doesn't match to tag nullable policy"
+	Customer      Customer
+	CreatedAt     int64 `gorm:"autoCreateTime"`
+	DeadlineDate  int64
+}
+
+type ProductType struct {
+	Id   uint `gorm:"primaryKey"`
+	Name string
+}
+
+type Customer struct {
+	Id      uint `gorm:"primaryKey"`
+	Title   string
+	Contact string
+	Orders  []Order `gorm:"foreignKey:CustomerId"`
+}