Enforce consistent acronyms and brands in variable names

[mrmckeb]

What are we trying to solve

To enforce consistent casing for acronyms.

Examples:

• toJson vs toJSON
• MdnLink vs MDNLink
• githubProfile vs gitHubProfile

There are many views on this, and many valid arguments for either approach.

Research

• Microsoft has a recommended approach: Abbreviations
• Google has a recommended approach: Camel case: defined
• There are multiple discussions on Stack Overflow:
  • https://stackoverflow.com/questions/15526107/acronyms-in-camelcase
  • https://stackoverflow.com/questions/4504508/camel-casing-acronyms

Recommendation

As with many of our decisions in the style guide, I feel we should opt for the solution that's easiest to lint.

• toJson
• MdnLink
• svgToPng

For brands, we should simply ignore casing and apply normal conventions (not lintable):

• githubProfile
• youtubeVideo
• paypalAccount

Unfortunately it's difficult to know programatically* if the XMLHTTP in XMLHTTPRequest is one or more acronyms, or a word that's incorrectly uppercased, just as it's impossible to know the opposite.

*Assuming we're not writing rules that use ML.

[mrmckeb]

Closing off as we can't think of a way to autofix this.