Im looking for an explanation of the use of such syntax. I wont bore with my interpretation.

Updated with improved questions : Would const customClaims only have 1 attribute? Does that as { role? : string } remove other attributes as well? What if user custom claims has no role attribute?

const customClaims = (user.customClaims || {role: ""}) as { role?: string };

CodePudding user response：

Let's break this down.

(user.customClaims || {role: ""}) is an expression that result in a value (let's call it