Beautify HTML output to prevent >990 char lines

[Alamantus]

Prevent long lines from being broken in Yahoo and Gmail clients.

I made this change before the 2.x update, but it's still a problem, so here it is again. 😄

[meriadec]

Thanks @Alamantus 😄

[meriadec]

Just realized that the PR was for master branch, so I removed commit & pushed it to develop branch (I need to document that in README, but I prefer keep master sync with releases, and do all development on develop).

Also, I added js-beautify to app dependencies :)

[meriadec]

@ngarnier in your opinion, will it conflict with minify output option ? Should we disable beautify when minify is enabled? Or maybe should we make beautify optional? (Like it is now, the MJML App output will not be the "real" MJML output anymore.

[ngarnier]

hey @meriadec, I guess the question is: should we add this beautify option in MJML instead of the app?

@Alamantus, have you seen the HTML output of MJML break because of the way it is formatted? I have never seen that, so it would be very useful if you could share a MJML template where this happens so I can reproduce.

Thanks!

[Alamantus]

@ngarnier It has happened to some of the marketing emails at work, but it was a while ago so I'd have to see if I can find them. In Gmail and Yahoo mail, the client was inserting a line break at about column 990 for some reason. I know it was those clients because the same HTML source came through in Outlook without the line breaks.

It's weird that you haven't encountered it before, though. We use an old version of ARPReach to distribute the emails rather than Mailjet, so maybe it's something happening in the send process, but that doesn't explain why it doesn't contain those line breaks in Outlook (where everything else usually does break).