hide character metrics console warnings on production - fixes #3853

[borriglione]

What is the previous behavior before this PR?

It logs console warnings if no metric was found for the character in the current font and mode.

What is the new behavior after this PR?

It logs console warnings only in non-production NODE_ENV

Fixes #3853

[edemaine]

Sorry for the delay in reviewing this. In addition to the style issues now highlighted below, there seems to a problem: process.env.NODE_ENV is getting evaluated and replaced at build time instead of at runtime. I see the following in dist/katex.js after running yarn build:

    const nodeEnv = typeof process !== 'undefined' && "production";

Presumably this is a feature of our build process (Webpack), and there's a way around it. Are you able to explore workarounds?

[kalvdans]

I think we can get rid of the warning completely, regardless of environment.

[edemaine]

@kalvdans The warning serves a purpose: it tells you that the height of the character is unknown, so there's a decent chance it will be placed incorrectly. (A good example is within a \sqrt.)

[kalvdans]

@kalvdans The warning serves a purpose: it tells you that the height of the character is unknown, so there's a decent chance it will be placed incorrectly. (A good example is within a \sqrt.)

Yes but what should the user (document writer) do about it?

If the message is aimed for font developers, a full list of missing metrics is more useful.