react-native-devtools-frontend/node_modules/stylelint/docs/developer-guide/processors.md

Writing processors

Processors are functions that hook into stylelint's pipeline, modifying code on its way into stylelint and modifying results on their way out.

Their use is discouraged in favor of PostCSS syntaxes.

Processor modules are functions that accept an options object and return an object with the following the functions, which hook into the processing of each file:

• code: A function that accepts two arguments, the file's code and the file's path, and returns a string for stylelint to lint.
• result: A function that accepts two arguments, the file's stylelint result object and the file's path, and either mutates the result object (returning nothing) or returns a new one.

// my-processor.js
module.exports = function (options) {
  return {
    code: function (input, filepath) {
      // ...
      return transformedCode;
    },
    result: function (stylelintResult, filepath) {
      // ...
      return transformedResult;
    }
  };
};

Processor options must be JSON-friendly because users will need to include them in .stylelintrc files.