fix: support abstract base entities

Author: Char2sGu

Diff for: __tests__/soft-delete.spec.ts

@@ -20,16 +20,23 @@ class UserDeletedAt extends BaseEntity {
   deletedAt?: Date;
 }
 
-@SoftDeletable(() => UserIsDeleted, "isDeleted", () => true, false)
+@SoftDeletable(() => SoftDeletableBaseEntity, "isDeleted", () => true, false)
 @Entity()
-class UserIsDeleted extends BaseEntity {
+abstract class SoftDeletableBaseEntity extends BaseEntity {
+  constructor(_a: string) {
+    super();
+  }
+
   @PrimaryKey()
   id!: number;
 
   @Property()
   isDeleted!: boolean;
 }
 
+@Entity()
+class UserIsDeleted extends SoftDeletableBaseEntity {}
+
 @SoftDeletable({
   type: () => UserIsDeleted,
   field: "isDeleted",

Diff for: src/decorator.ts

@@ -8,10 +8,7 @@ import {
   SoftDeletableConfig,
 } from "./common";
 
-interface Type<T> {
-  new (...args: any[]): T;
-  prototype: T;
-}
+type Type<Entity> = abstract new (...args: any[]) => Entity;
 
 type EntityDecorator<Entity> = (type: Type<Entity>) => void;