nodejs/tools/eslint-rules/lowercase-name-for-primitive.js

/**
 * @fileoverview Check that TypeError[ERR_INVALID_ARG_TYPE] uses
 *               lowercase for primitive types
 * @author Weijia Wang <starkwang@126.com>
 */
'use strict';

//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------

const astSelector = 'NewExpression[callee.property.name="TypeError"]' +
                    '[arguments.0.value="ERR_INVALID_ARG_TYPE"]';

const primitives = [ 'number', 'string', 'boolean', 'null', 'undefined' ];

module.exports = {
  meta: { fixable: 'code' },
  create(context) {
    function checkNamesArgument(node) {
      const names = node.arguments[2];

      switch (names.type) {
        case 'Literal':
          checkName(names);
          break;
        case 'ArrayExpression':
          names.elements.forEach((name) => {
            checkName(name);
          });
          break;
      }
    }

    function checkName(node) {
      const name = node.value;
      const lowercaseName = name.toLowerCase();
      if (name !== lowercaseName && primitives.includes(lowercaseName)) {
        const msg = `primitive should use lowercase: ${name}`;
        context.report({
          node,
          message: msg,
          fix: (fixer) => {
            return fixer.replaceText(
              node,
              `'${lowercaseName}'`,
            );
          },
        });
      }

    }

    return {
      [astSelector]: (node) => checkNamesArgument(node),
    };
  },
};