Stripping of newlines in comments when preceded by carriage returns

[brettz9]

Hi,

Our users for eslint-plugin-jsdoc have reported problems with Vue in passing on preserving newlines within the ESLint AST comments property when carriage returns are also present (preceding them).

I've confirmed that @babel/eslint-parser does not strip the newlines when interpreting the text within the user's <script> tag, but when supplying the text to vue-eslint-parser, though the carriage returns our preserved, the newlines are stripped, producing comment AST like the following, causing our plugin to report errors when there should be none:

[
  {
    type: 'Block',
    value: '*\r       * @description TESTSTETSTST\r       * @param {string} arg - lorem\r       * @return {string} - someDescription\r       ',
    // ...
  }
]

However, I see that in the likes of templateBody AST, at least, instead of newlines being missing, the newlines are present (and the carriage returns are not added), as perhaps is expected. But for comments, there is the above problem.

Code to reproduce (in a type: "module" package):

import {parseForESLint} from 'vue-eslint-parser';

const parsed = parseForESLint(`\r
  <template>\r
    <div>HELLO WORLD</div>\r
  </template>\r
\r
  <script>\r
  export default {\r
    computed: {\r
      /**\r
       * @description TESTSTETSTST\r
       * @param {string} arg - lorem\r
       * @return {string} - someDescription\r
       */\r
      isForTestingLint (arg) {\r
        return arg;\r
      },\r
    },\r
  };\r
  </script>\r
`, {
  parser: "@babel/eslint-parser"
})

console.log('parsed', parsed.ast.comments);

[ota-meshi]

Thank you for this issue!

It looks like a bug to me. I think we need to replace those CRLF with LF.

[brettz9]

Thanks! If possible, though, I think it might be more ideal for us if you could preserve them so that when fixing comments for people, our parser remains aware of the original line endings.

[brettz9]

The comments are kind of an exception to the Abstract part of the AST acronym (Abstract Syntax Tree), so I think it makes sense there to retain the full exact formatting data.

[ota-meshi]

Thank you for your opinion.
As you say, I think it makes sense to preserve the original line endings in the AST of the script comment in <script>.