Error thrown on single-line mixin include without semicolon

[jwilsson]

Originally reported at lesshint/lesshint#490

• Node Version: 10.9.0
• NPM Version: 6.2.0
• postcss-less Version: 2.0.0

If you have a large amount of code to share which demonstrates the problem you're experiencing, please provide a link to your
repository rather than pasting code. Otherwise, please paste relevant short snippets below.

LESS

.foo{.bar("baz")}

JavaScript

const postcss = require('postcss');
const syntax = require('postcss-less');

const lessText = `.foo{.bar("baz")}`;

postcss([])
  .process(lessText, { syntax: syntax })
  .then(function (result) {
    console.log(result.root.first)
  })
  .catch((e) => {
      console.error(e);
  });

Errors

CssSyntaxError {
  name: 'CssSyntaxError',
  reason: 'Unknown word',
  source: '\n.foo{.bar("baz")}\n',
  line: 2,
  column: 16,
  message: '<css input>:2:16: Unknown word',
  input: { line: 2, column: 16, source: '\n.foo{.bar("baz")}\n' }
}

Expected Behavior

Return an AST without any errors.

Actual Behavior

The above error is thrown. Adding a semicolon before } fixes it though.

How can we reproduce the behavior?

Run the JS code above.

[zhangzhiqiang37]

Excuse me, is there any fix progress about this issue?

[shellscape]

@zhangzhiqiang37 github will show activity above if there is any. as of 20 days ago, there is no activity.

[shellscape]

Well the semicolon is just a false flag on this one. A semicolon short-circuits the parsing and returns the proper rule. But the real issue here is that there's a combination of parens and a string param there that seems to be throwing the parsing off. I've spent 4 hours and tried a half dozen different ways to resolve this and nothing will satisfy all scenarios. One fix results in other breakages.

If anyone wants this fixed, it's going to have to come from an outside contributor. 4 hours is my max.

[shellscape]

So I ended up rewriting the entire parser on PostCSS v7. 00995e5 adds a test to assert that this doesn't throw an error any longer.

[zhangzhiqiang37]

So... I will see this new feature in next version of lesshint? @jwilsson

[jwilsson]

@zhangzhiqiang37 Yes, eventually. There are still some things to work out with this upgrade.