Correct Answer : koa-validator
Explanation : koa-validator is a data validation middleware that allows you to validate request data.
Correct Answer : App.keys
Explanation : app.keys, property is used to specify the keys that will be used to sign and verify cookies.
app.keys
Correct Answer : Cascading
Explanation : Cascading in Koa.js refers to the sequence in which middleware functions are run.
Correct Answer : Cookies
Explanation : Cookies are basic, short files/data that are given to the client in conjunction with a server request and saved on the client side.