fix pvpDefense ref无法找到目标

shared/db/PvpDefense.ts

@@ -55,13 +55,13 @@ class Robot {
 }
 
 class OppPlayers {
-    @prop({ ref: PvpDef, type: mongoose.Schema.Types.ObjectId })
+    @prop({ ref: 'PvpDefense', type: mongoose.Schema.Types.ObjectId })
     oppDef: Ref<PvpDef>;
     @prop({ required: true })
     pos: number;
     @prop({ required: true })
     isRobot: boolean;
-    @prop({ required: true, type: Robot, default: [], _id: false })
+    @prop({ required: true, type: Robot, default: null, _id: false })
     robot: Robot
 }
 
@@ -78,7 +78,7 @@ export default class PvpDefense extends BaseModel {
     roleId: string;					// 角色 id
     @prop({ required: true })
     roleName: string;				// 角色名称
-    @prop({ ref: Role, type: mongoose.Schema.Types.ObjectId })
+    @prop({ ref: 'Role', type: mongoose.Schema.Types.ObjectId })
     role: Ref<Role>;
     @prop({ required: true, type: Heroes, default: getInitialOppHeros(), _id: false })
     heroes: Array<Heroes>;
@@ -92,7 +92,7 @@ export default class PvpDefense extends BaseModel {
     defCe: number;                 //防守ce
     @prop({ required: true, type: OppPlayers, default: getInitialOppPlayers(), _id: false })
     oppPlayers: Array<OppPlayers>;
-    @prop({ ref: SystemConfig, type: mongoose.Schema.Types.ObjectId })
+    @prop({ ref: 'SystemConfig', type: mongoose.Schema.Types.ObjectId })
     map: Ref<SystemConfig>;
     @prop({ required: true, type: HidScores, default: [] })
     hidScores: Array<HidScores>;