Discussion on: TypeScript Might Not Be Your God: Case Study of Migration from TS to JSDoc

[Vladyslav Zubko]

Hello @teamradhq !

Cool that you also like JSDoc!

Thanks for providing such a detailed guide on how type checking works during the build! I hope everyone reading this article will also go through the comments since there is a lot of useful information here.

Regarding react-create-app, even if it's deprecated and everyone prefers Vite now, it is still used in many old projects. Actually, I've been a react-create-app hater since its creation, always preferring to configure Webpack myself, or at least eject the react-create-app to have control over my app's build. Disabling type checking during build is usually the first thing I did. But the problem is not everyone is as curious as we are. Unfortunately, many still use the "standard" react-create-app, where type checking happens before the build. Although this has become less common lately because Vite is doing its job 👍

I'm curious to know what the equivalent of overloading a function would be in docblock:

To be honest, I try not to use overloads in production applications. In applications, I find it better to use multiple functions. Overloads, in my opinion, are more suitable for libraries.

If anything, I'm not making excuses 😄 You can create overloads with JSDoc just as conveniently as in TypeScript using the @overload tag. You can learn more about it here - devblogs.microsoft.com/typescript/...

Example:

/**
 * @overload
 * @param {string} value
 * @return {void}
 */

/**
 * @overload
 * @param {number} value
 * @param {number} [maximumFractionDigits]
 * @return {void}
 */

/**
 * @param {string | number} value
 * @param {number} [maximumFractionDigits]
 */
function printValue(value, maximumFractionDigits) {
    if (typeof value === "number") {
        const formatter = Intl.NumberFormat("en-US", {
            maximumFractionDigits,
        });
        value = formatter.format(value);
    }

    console.log(value);
}

I'm not trying to convince you to use or not use TypeScript or suggest that you're entirely wrong. I just want you to know that transpiling TypeScript is not slower than JavaScript. Type checking is the slow part, and it's really only necessary when integrating your change upstream :)

I completely understand and agree with you! However, not everyone grasps this concept, and that's the gist of my article. Everything described in the first paragraph. I have to work with many teams, and each has its reasons for adopting or not adopting TypeScript. I'm just highlighting that going all-in with TypeScript (using .ts files) is not the sole solution to type checking in a project. Action is needed, not just praying to the TypeScript-God!

Thank you so much for your comments! I'm sure they added value to the article!