Development build of Hyperapp

As discussed on Slack, I’m creating this issue so we can have a discussion about having a separate build of Hyperapp that developers can use for better debugging and detailed error messages.

Why?

Today, I stumbled upon an issue where the h function wouldn’t accept a date, like {new Date()}. Which is reasonable, except I got an error that I had a hard time understanding at first, which was Uncaught TypeError: Cannot read property 'length' of undefined. You can see a reproduction of the error here: https://codepen.io/vdsabev/pen/Ewpggx

Hyperapp already has a great developer experience due to having so few concepts to learn. To make the learning process (and beyond) even easier, I think the community would benefit from enhanced error messages in cases like mine. This, however, can’t come at the cost of bloating the library - at least not in production.

This issue is about showing better errors. #388 is somewhat related - it’s about showing the errors in a better way.

An example of what React does is: react-dom.development.js:65 Uncaught Error: Objects are not valid as a React child (found: Thu Oct 12 2017 19:55:23 GMT+0300 (Eastern European Summer Time)). If you meant to render a collection of children, use an array instead.

So?

What do you all think? Approaches, examples, alternatives?

Your move.

[jorgebucaran]

We could start by just distributing an unminified file in dist since that would involve zero special maintenance.

[vdsabev]

From the Slack discussions, another use case @selfup bumped into: he used the obsolete root property. A development build could throw an error if any unknown properties are used in the app function call. Or show warnings for deprecated properties, including migration steps.