Turning a function signature into a type?


Turning a function signature into a type?



I have property that is a function and it is typed like this:


/**
* Function that performs the validation.
*/
validate: (vc: ValidationContext, object:any)=>boolean;



The same type signature is used in the class constructor:


constructor(validate: (vc: ValidationContext, object:any)=>boolean) {}



So if I change the signature in one place then I have to change it in another. Is it possible to define a type that encapsulates the type. Something like:


type ValidateType = (vc: ValidationContext, object:any)=>boolean



That way the validate type can be updated in one place?


validate



Per the comments I got a little lucky in this question. This is how I implemented it (@cartant if you would to put this in an answer so you can get credit I'll delete it from here):


/**
* The type api signature for the validation function.
*/
type ValidationFunctionType = (vc: ValidationContext, object:any)=>boolean;





Yes, it's possible. You'd declare the type exactly as you've declared it in your question: type ValidateType = (vc: ValidationContext, object: any) => boolean. Or you could declare it using an interface: interface ValidateType { (vc: ValidationContext, object: any) => boolean }.
– cartant
2 days ago



type ValidateType = (vc: ValidationContext, object: any) => boolean


interface ValidateType { (vc: ValidationContext, object: any) => boolean }





Really??? Wow got pretty lucky on that one! Thanks!
– Ole
2 days ago









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