Add quiet option to Node API

[duanehutchins]

Clearly describe the bug

The Node API ignores the quiet option. You can confirm that the quiet option is not used in lib/standalone.js.

Example gulpfile.js:

gulp.task('stylelint', () => {
    const stylelint = require('stylelint');
    const options = Object.assign(argv, {
        files: 'sass/**/*.scss',
        formatter: 'string',
        quiet: true,
      });
    return stylelint.lint(options).then(data => {
        console.log(data.output);
    });
});

Even though quiet: true, the warnings are not suppressed.

Which version of stylelint are you using?

12.0.0

How are you running stylelint: CLI, PostCSS plugin, Node.js API?

Node.js API

Does the bug relate to non-standard syntax (e.g. SCSS, Less etc.)?

No

What did you expect to happen?

Warnings should be suppressed in quiet mode. Example:

$ npm run stylelint
/src/sass/_mixins.scss:101:2: Expected single space before "{" (block-opening-brace-space-before) [error]

1 problem

What actually happened (e.g. what warnings or errors did you get)?

Warnings are not suppressed. Example:

$ npm run stylelint
/src/sass/_mixins.scss:101:2: Expected single space before "{" (block-opening-brace-space-before) [error]
/src/sass/_mixins.scss:234:18: Unexpected !important (declaration-no-important) [warning]
/src/sass/_mixins.scss:238:20: Unexpected !important (declaration-no-important) [warning]

3 problems

[alexander-akait]

i think quiet option only for CLI

[jeddy3]

Is there any reason we don't allow it to be used by the Node API? If not, we could add it.

[jeddy3]

As it's a valid use case (where a user wants data.output to be filtered of errors when using the Node.js API) and there are no objections, I've labelled the issue as ready to implement. Please consider contributing if you have time.

You'll need to move quiet out from the CLI docs and into the Options docs in the pull request.

[glen-84]

@jeddy3 I think this should be closed? (#5542)