diff --git a/src/core/domain/Entity.ts b/src/core/domain/Entity.ts
index 34f23c9..2be18a8 100644
--- a/src/core/domain/Entity.ts
+++ b/src/core/domain/Entity.ts
@@ -9,8 +9,8 @@ export abstract class Entity<T> {
   protected readonly _id: UniqueEntityID;
   public readonly props: T;
 
-  constructor (props: T, id?: UniqueEntityID) {
-    this._id = id ? id : new UniqueEntityID();
+  constructor (props: T, id = new UniqueEntityID() ) {
+    this._id = id;
     this.props = props;
   }
 
diff --git a/src/core/domain/UniqueEntityID.ts b/src/core/domain/UniqueEntityID.ts
index fd76e4f..3a90080 100644
--- a/src/core/domain/UniqueEntityID.ts
+++ b/src/core/domain/UniqueEntityID.ts
@@ -3,7 +3,7 @@ import uuid from 'uuid/v4';
 import { Identifier } from './Identifier'
 
 export class UniqueEntityID extends Identifier<string | number>{
-  constructor (id?: string | number) {
-    super(id ? id : uuid())
+  constructor (id: string | number = uuid()) {
+    super(id);
   }
 }
\ No newline at end of file
diff --git a/src/core/domain/WatchedList.ts b/src/core/domain/WatchedList.ts
index 54edf55..0694997 100644
--- a/src/core/domain/WatchedList.ts
+++ b/src/core/domain/WatchedList.ts
@@ -6,9 +6,9 @@ export abstract class WatchedList<T> {
   private new: T[];
   private removed: T[];
 
-  constructor (initialItems?: T[]) {
-    this.currentItems = initialItems ? initialItems : [];
-    this.initial = initialItems ? initialItems : [];
+  constructor (initialItems: T[] = []) {
+    this.currentItems = initialItems;
+    this.initial = initialItems;
     this.new = [];
     this.removed = [];
   }
diff --git a/src/core/infra/BaseController.ts b/src/core/infra/BaseController.ts
index 653c515..faaed90 100644
--- a/src/core/infra/BaseController.ts
+++ b/src/core/infra/BaseController.ts
@@ -31,32 +31,32 @@ export abstract class BaseController {
     return res.sendStatus(201);
   }
 
-  public clientError (message?: string) {
-    return BaseController.jsonResponse(this.res, 400, message ? message : 'Unauthorized');
+  public clientError (message = 'Unauthorized') {
+    return BaseController.jsonResponse(this.res, 400, message);
   }
 
-  public unauthorized (message?: string) {
-    return BaseController.jsonResponse(this.res, 401, message ? message : 'Unauthorized');
+  public unauthorized (message = 'Unauthorized') {
+    return BaseController.jsonResponse(this.res, 401, message);
   }
 
-  public paymentRequired (message?: string) {
-    return BaseController.jsonResponse(this.res, 402, message ? message : 'Payment required');
+  public paymentRequired (message = 'Payment required') {
+    return BaseController.jsonResponse(this.res, 402, message);
   }
 
-  public forbidden (message?: string) {
-    return BaseController.jsonResponse(this.res, 403, message ? message : 'Forbidden');
+  public forbidden (message = 'Forbidden') {
+    return BaseController.jsonResponse(this.res, 403, message);
   }
 
-  public notFound (message?: string) {
-    return BaseController.jsonResponse(this.res, 404, message ? message : 'Not found');
+  public notFound (message = 'Not found') {
+    return BaseController.jsonResponse(this.res, 404, message);
   }
 
-  public conflict (message?: string) {
-    return BaseController.jsonResponse(this.res, 409, message ? message : 'Conflict');
+  public conflict (message = 'Conflict') {
+    return BaseController.jsonResponse(this.res, 409, message);
   }
 
-  public tooMany (message?: string) {
-    return BaseController.jsonResponse(this.res, 429, message ? message : 'Too many requests');
+  public tooMany (message = 'Too many requests') {
+    return BaseController.jsonResponse(this.res, 429, message);
   }
 
   public todo () {