how to access constants declared via Object.defineProperty

Question

i am learning how to declare app-wide globla constatnts. referring to this post here for the answer of Dominic Barnes, for the code titled with constants.js -- Better. i copied it and pasted it as shown in the following lines:

constants.js

function define(name, value) {
    Object.defineProperty(exports, name, {
        value:      value,
        enumerable: true
    });
}

define("PI", 3.14);

invocation to constants.js in app.js

import constants from './constants/constants';
var req=https.get('https://xx/xx/getDistanceFromOriginToDestination/30.976639,30.056021,30.97775,30.033333',options, callback);
constants. //<==========????
req.on('error', (e) => {
    console.error("problem with request:", e);
});
req.end();

the propblem is, in the post of the Dominic Barnes he can access the PI as follows and as shown in his answer:

var constants = require("./constants");
console.log(constants.PI); // 3.14
constants.PI = 5;
console.log(constants.PI); // still 3.14

in my case, the autocomplete of VS-Codes does not show any thing derived from constants.js, or in other words, i can not have access to PI. please let me know what i am missing to chieve accessing the constant PI declared in constants.js

Answer 1

VSCode uses Typescript type information in order to provide intellisense like auto-completion and argument hints.

You can create your own module type descriptor for the constants JavaScript module. Add a new constants.d.ts file along-side constants.js with the following contents

export declare const PI: number;

---

You can see the results in the below CodeSandbox example

Without the .d.ts descriptor, the editor does not know about constants.PI

But as soon as the descriptor is enabled, you get auto-completion and type hints

Note that in either case, the code compiles and displays the correct value.