The goal is to declare a Record type definition for a mapper in order to restrict the keys and function values.
The arguments of those functions have different behaviors, thus are defined using a union type.
PushNotificationPayloadVideoComment is part of PushNotificationPayload union type, but the TS compiler detects that it's not assignable to its union
TypeScript version: 4.3.2
Click here for the full code snippet on TS Playground
CodePudding user response：
Using unknown means the function assigned should be capable to handle any parameter type, and you are using functions that can only handle a specific type.
You could use a custom mapped type to map each callback to the appropriate parameter type:
type Mapper = {
[P in PushNotificationPayload as P['category']]?: (payload: P) => void
}