Development warnings

[Rich-Harris]

There are a few things that can't be caught with static analysis, such as missing data on first render. Is better if we only check those things in development mode, since it's unnecessary code in production otherwise.

[PaulBGD]

Would this be a check like if (process.env.NODE_ENV !== 'production') ?

[Rich-Harris]

Something like that, yes — or maybe a compile option, like

const { code, map } = svelte.compile( template, {
  dev: true
});

[PaulBGD]

I think I've gotten too used to working with view frameworks.

[Rich-Harris]

Implemented in 1.9.0