Integrating JavaScript functions into TypeScript

Question

Integrating JavaScript functions into TypeScript

When converting a JavaScript function to TypeScript, I encountered an issue. The function works fine in JS but in TS, I receive the following error:

[ts] Cannot find name 'PasscodeAuth'. Did you mean 'passcodeAuth'?

function passcodeAuth() {
  return PasscodeAuth.isSupported()
    .then(() => {
      return PasscodeAuth.authenticate()
    })
    .then(success => {
      AlertIOS.alert('Authenticated Successfully');
    })
    .catch(error => {
      console.log(error)
      AlertIOS.alert(error.message);
    });
}

The 'PasscodeAuth' entity is not imported or defined anywhere, yet it functions correctly in JavaScript. How can I make it recognizable for TypeScript? In JavaScript, I can use any word as a parameter and still have access to 'isSupported' and 'authenticate', even if it's not a real parameter. Any suggestions on how to resolve this for TypeScript?

Appreciate any insights! Thanks!

javascript typescript

Answer 1

Answer №1

In the context of whether or not PasscodeAuth truly exists, you can notify typescript about it using a declare statement. Here is an example:

// Place this at the top level of the file that uses PasscodeAuth
declare const PasscodeAuth: any;

This will define PasscodeAuth as a variable with the type any. Consequently, you can utilize it in your file without encountering errors related to that variable. However, since it is typed as any, you will not benefit from type safety. If you happen to know the specific type for it, you can specify a more precise type instead of any.

A declare statement merely serves as a type annotation and does not have any impact on the resulting JavaScript code. It seems that your code functions correctly despite the TypeScript errors, so incorporating a declaration appears to be the appropriate solution.

Answer 2

In the context of whether or not PasscodeAuth truly exists, you can notify typescript about it using a declare statement. Here is an example:

// Place this at the top level of the file that uses PasscodeAuth
declare const PasscodeAuth: any;

This will define PasscodeAuth as a variable with the type any. Consequently, you can utilize it in your file without encountering errors related to that variable. However, since it is typed as any, you will not benefit from type safety. If you happen to know the specific type for it, you can specify a more precise type instead of any.

A declare statement merely serves as a type annotation and does not have any impact on the resulting JavaScript code. It seems that your code functions correctly despite the TypeScript errors, so incorporating a declaration appears to be the appropriate solution.

Integrating JavaScript functions into TypeScript

Answer №1

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