It’s not possible for Typescript to reach an exported function in a different module

Question

It’s not possible for Typescript to reach an exported function in a different module

Having trouble referencing and using exported methods from another module. I keep getting an error that says 'There is no exported member in SecondModule'.

module FirstModule{
    export class someClass{
         constructor(method: SecondModule.exMethod)   //Error occurs here: 'There is no exported member in SecondModule'
         {}
    }
}

module SecondModule{
    export function exMethod(){
        return function(input){
             //perform some actions
             return result;
        }
    }

}

angularjs visual-studio typescript

Answer 1

Answer №1

It is not possible to use a function reference as a type directly, but you can limit the constructor to a specific function type that accepts functions with a signature similar to exMethod.

Check out this code snippet for an example:

module FirstModule {
    export class MyClass {
         constructor(method: () => (input) => any) {
         }
    }
}

module SecondModule {
    export function exMethod() {
        return function(input) {
             // do something
             return result;
        }
    }
}

new FirstModule.MyClass(SecondModule.exMethod); // This works fine
new FirstModule.MyClass(() => {});              // This will throw an error

If you absolutely need to ensure that only SecondModule.exMethod is passed in, you can skip the parameter and call the function directly within MyClass:

module FirstModule {
    export class MyClass {
         constructor() {
             SecondModule.exMethod()(5); // Example of calling the method
         }
    }
}

Answer 2

It is not possible to use a function reference as a type directly, but you can limit the constructor to a specific function type that accepts functions with a signature similar to exMethod.

Check out this code snippet for an example:

module FirstModule {
    export class MyClass {
         constructor(method: () => (input) => any) {
         }
    }
}

module SecondModule {
    export function exMethod() {
        return function(input) {
             // do something
             return result;
        }
    }
}

new FirstModule.MyClass(SecondModule.exMethod); // This works fine
new FirstModule.MyClass(() => {});              // This will throw an error

If you absolutely need to ensure that only SecondModule.exMethod is passed in, you can skip the parameter and call the function directly within MyClass:

module FirstModule {
    export class MyClass {
         constructor() {
             SecondModule.exMethod()(5); // Example of calling the method
         }
    }
}

It’s not possible for Typescript to reach an exported function in a different module

Answer №1

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