Type Alias MethodNames<T>

MethodNames<T>: {
    [K in keyof T]: T[K] extends ((...args: any[]) => any)
        ? K
        : never
}[keyof T]

Extract the method key names from a class

Type Parameters

  • T

Example

class MyClass {
       constructor() {}
       aMethod() {}
       anotherMethod() {}
       aField = 'foo'
       anotherField = 42
     }

     type MethodNamesMyClass = MethodNames<MyClass>
     expectType<TypeEqual<MethodNamesMyClass, 'aMethod' |'anotherMethod'>>(true)

Note

constructor is not included

Credit

Original code from https://zirkelc.dev/posts/extract-class-methods