feat: support optional inject in constructor

Author: gxkl

core/core-decorator/src/decorator/Inject.ts

@@ -36,14 +36,17 @@ export function Inject(param?: InjectParams | string) {
   function constructorInject(target: any, parameterIndex: number) {
     const argNames = ObjectUtils.getConstructorArgNameList(target);
     const argName = argNames[parameterIndex];
-    // TODO get objName from design:type
-    const objName = typeof param === 'string' ? param : param?.name;
     const injectObject: InjectConstructorInfo = {
       refIndex: parameterIndex,
       refName: argName,
-      objName: objName || argName,
+      // TODO get objName from design:type
+      objName: injectParam?.name || argName,
     };
 
+    if (injectParam?.optional) {
+      injectObject.optional = true;
+    }
+
     PrototypeUtil.setInjectType(target, InjectType.CONSTRUCTOR);
     PrototypeUtil.addInjectConstructor(target as EggProtoImplClass, injectObject);
   }

core/types/core-decorator/model/InjectConstructorInfo.ts

@@ -13,4 +13,8 @@ export interface InjectConstructorInfo {
    * obj's name will be injected
    */
   objName: EggObjectName;
+  /**
+   * optional inject
+   */
+  optional?: boolean;
 }