feat(jss): Add format option to SheetsRegistry.toString()

[briganti]

What Would You Like to Add/Fix?

This PR adds a new option format to SheetsRegistry.toString so whitespaces are removed from stringified CSS.

jss.createRule('a', {float: 'left', width: '1px'})

// Default
rule.toString()
// outputs:
// .a-id {
//   float: left;
//   width: 1px;
// }

// With format:false
rule.toString({format: false}))
// outputs:
// .a-id{float:left;width:1px;}

Todo

• [x] Add test(s) that verify the modified behavior
• [ ] Add documentation if it changes public API

Expectations on Changes

Indentation and line breaks are removed when format: false is passed to SheetsRegistry.toString or rule.toString methods.

Changelog

• Add a new option format for removing whitespaces in SheetsRegistry.toString(options)

[kof]

I am not sure regarding "uglify" as an option name, because it may let people think its gonna do more than removing white spaces, but we won't add anything else than whitespace removal because real modification is costly at runtime.

[kof]

How about "removeWhitespace" or "compact" or "format"

[kof]

If "format" it would be true by default.

[briganti]

Thanks for the fast review @kof. I've updated the PR to take into account your feedback.

[kof]

merged, thank you

[kof]

released in https://github.com/cssinjs/jss/releases/tag/v10.8.0