no-this-in-before-route-enter.js

/**
 * @fileoverview Don't use this in a beforeRouteEnter method
 * @author Przemyslaw Jan Beigert
 */
"use strict";

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

const utils = require('../utils');

"use strict";
/**
 * @param {FunctionExpression | BlockStatement | Property | ThisExpression} obj
 * @returns {boolean}
 */
function deepFindThisExpression(obj) {
  if (typeof obj !== 'object' || !obj) {
    return false;
  }
  if (obj.type === 'ThisExpression') {
    return true;
  }

  /** @param {typeof obj} key */
  return Object.entries(obj).some(([key, value]) => {
    if (key === 'parent') {
      return false;
    }
    if (Array.isArray(value)) {
      return value.some(item => deepFindThisExpression(item));
    }
    if (typeof value === 'object') {
      return deepFindThisExpression(value);
    }

    return false;
  })
}

/**
 * @param {Property | SpreadElement} property
 * @returns {property is Property}
 */
function isPropertyBeforeRouteMethod(property) {
  if (property.type !== 'Property') {
    return false;
  }

  return property.key.type === 'Identifier' && property.key.name === 'beforeRouteEnter';
}

const errorMessage = 'beforeRouteEnter does NOT have access to `this` component instance. https://router.vuejs.org/guide/advanced/navigation-guards.html#in-component-guards'

module.exports = {
  errorMessage: errorMessage,
  meta: {
    type: 'suggestion',
    docs: {
      description: 'Do not this in beforeRouteEnter',
      categories: null,
      url: 'https://eslint.vuejs.org/rules/no-this-in-before-route-enter.html'
    },
  },

  /** @param {RuleContext} context */
  create: function (context) {
    // ----------------------------------------------------------------------
    // Public
    // ----------------------------------------------------------------------
    return utils.executeOnVue(context, (obj) => {
      const beforeRouteProperty = obj.properties.find(isPropertyBeforeRouteMethod);
      if (!beforeRouteProperty) {
        return;
      }
      if (beforeRouteProperty.value.type !== 'FunctionExpression') {
        return;
      }
      if (deepFindThisExpression(beforeRouteProperty.value.body)) {
        context.report({
          node: beforeRouteProperty,
          message: errorMessage,
        });
      }
    });
  }
};