Broken typescript definitions for twiml

[controversial]

The type definitions that ship for TwiML classes should say what types the methods return, rather than specifying any, which is useless for type checking.

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In the following example:

const message = new twilio.twiml.MessagingResponse();
const markup = message.toString();

the type of markup is any, rather than string, which makes the value useless for type checking.

Typescript projects using typescript-eslint will struggle to use this value:

const myTwiml = new twilio.twiml.MessagingResponse();
const markup = myTwiml.toString();
return new Response(markup, { headers: { 'Content-Type': 'text/xml' } });

eslint will raise:

error  Unsafe assignment of an `any` value                                                          @typescript-eslint/no-unsafe-assignment
error  Unsafe argument of type `any` assigned to a parameter of type `BodyInit | null | undefined`  @typescript-eslint/no-unsafe-argument

[manisha1997]

Thanks for raising the issue. We will check this