canonical/node_modules/eslint-plugin-import/src/rules/no-commonjs.js

Canonical code style linter and formatter for JavaScript, SCSS, CSS and JSON.

/**
 * @fileoverview Rule to prefer ES6 to CJS
 * @author Jamund Ferguson
 */

const EXPORT_MESSAGE = 'Expected "export" or "export default"'
    , IMPORT_MESSAGE = 'Expected "import" instead of "require()"'

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


module.exports = function (context) {

  return {

    'MemberExpression': function (node) {

      // module.exports
      if (node.object.name === 'module' && node.property.name === 'exports') {
        if (allowPrimitive(node, context)) return
        context.report({ node, message: EXPORT_MESSAGE })
      }

      // exports.
      if (node.object.name === 'exports') {
        context.report({ node, message: EXPORT_MESSAGE })
      }

    },
    'CallExpression': function (call) {
      if (context.getScope().type !== 'module') return

      if (call.callee.type !== 'Identifier') return
      if (call.callee.name !== 'require') return

      if (call.arguments.length !== 1) return
      var module = call.arguments[0]

      if (module.type !== 'Literal') return
      if (typeof module.value !== 'string') return

      // keeping it simple: all 1-string-arg `require` calls are reported
      context.report({
        node: call.callee,
        message: IMPORT_MESSAGE,
      })
    },
  }

}

  // allow non-objects as module.exports
function allowPrimitive(node, context) {
  if (context.options.indexOf('allow-primitive-modules') < 0) return false
  if (node.parent.type !== 'AssignmentExpression') return false
  return (node.parent.right.type !== 'ObjectExpression')
}