feat(mongoose): Add VirtualRef decorator

packages/mongoose/src/decorators/index.ts

@@ -6,5 +6,6 @@ export * from "./postHook";
 export * from "./preHook";
 export * from "./ref";
 export * from "./schema";
-export * from "./unique";
 export * from "./select";
+export * from "./unique";
+export * from "./virtualRef";

packages/mongoose/src/decorators/virtualRef.ts

@@ -0,0 +1,49 @@
+import {PropertyMetadata, PropertyRegistry} from "@tsed/common";
+import {MONGOOSE_SCHEMA} from "../constants";
+
+export type VirtualRef<T> = T | null;
+export type VirtualRefs<T> = T[];
+
+/**
+ * Define a property as mongoose virtual reference to other Model (decorated with @Model).
+ *
+ * Warning: To avoid circular dependencies, do not use the virtual reference model in
+ * anything except a type declaration. Using the virtual reference model will prevent
+ * typescript transpiler from stripping away the import statement and cause a circular
+ * import in node.
+ *
+ * ### Example
+ *
+ * ```typescript
+ *
+ * @Model()
+ * class FooModel {
+ *
+ *    @VirtualRef("Foo2Model", "foo")
+ *    field: VirtualRef<Foo2Model>
+ *
+ *    @VirtualRef("Foo2Model", "foo")
+ *    list: VirtualRefs<Foo2Model>
+ * }
+ *
+ * @Model()
+ * class Foo2Model {
+ *    @Ref(FooModel)
+ *    foo: Ref<FooModel>;
+ * }
+ * ```
+ *
+ * @param type
+ * @returns {Function}
+ * @decorator
+ * @mongoose
+ */
+export function VirtualRef(type: string, foreignField: string) {
+  return PropertyRegistry.decorate((propertyMetadata: PropertyMetadata) => {
+    propertyMetadata.store.merge(MONGOOSE_SCHEMA, {
+      ref: type,
+      localField: propertyMetadata.name,
+      foreignField
+    });
+  });
+}

packages/mongoose/test/decorators/virtualRef.spec.ts

@@ -0,0 +1,23 @@
+import {Store} from "@tsed/core";
+import {descriptorOf} from "@tsed/core";
+import {MONGOOSE_SCHEMA} from "../../src/constants";
+import {VirtualRef} from "../../src/decorators";
+import {expect} from "chai";
+
+describe("@VirtualRef()", () => {
+  class Test {}
+  class RefTest {}
+
+  before(() => {
+    VirtualRef("RefTest", "foreign")(Test, "test", descriptorOf(Test, "test"));
+    this.store = Store.from(Test, "test", descriptorOf(Test, "test"));
+  });
+
+  it("should set metadata", () => {
+    expect(this.store.get(MONGOOSE_SCHEMA)).to.deep.eq({
+      ref: "RefTest",
+      foreignField: "foreign",
+      localField: "test"
+    });
+  });
+});