gistfile1.txt

const stylelint = require('stylelint');
const valueParser = require('postcss-value-parser');

const ruleName = 'plugin/valid-css-var';
const messages = stylelint.utils.ruleMessages(ruleName, {
  expected: (variable) => `Expected "${variable}" to be a valid CSS variable`,
});

module.exports = stylelint.createPlugin(ruleName, (primaryOption, secondaryOptions, context) => {
  return (root, result) => {
    const validOptions = stylelint.utils.validateOptions(result, ruleName, {
      // Validation options if any
    });

    if (!validOptions) {
      return;
    }

    root.walkDecls((decl) => {
      const value = decl.value;
      // Parse the value to find variables
      const parsedValue = valueParser(value);

      parsedValue.walk((node) => {
        if (node.type === 'function' && node.value === 'var') {
          // Example check: ensure the variable is defined
          const variableName = node.nodes[0].value;
          if (!isValidVariable(variableName, root)) {
            stylelint.utils.report({
              ruleName,
              result,
              node: decl,
              message: messages.expected(variableName),
            });
          }
        }
      });
    });
  };
});

function isValidVariable(variableName, root) {
  // Implement logic to check if variable is valid.
  // This could involve checking if the variable is defined in the :root selector
  // or checking against a list of known valid variables.
  let isValid = false;
  // Example: Checking for variable definition in :root
  root.walkRules(':root', (rule) => {
    rule.walkDecls(`--${variableName}`, (decl) => {
      isValid = true;
    });
  });
  return isValid;
}

module.exports.ruleName = ruleName;
module.exports.messages = messages;