require-v-if-inside-transition.js

/**
 * @author Yosuke Ota
 * See LICENSE file in root directory for full license.
 */
'use strict'

// ------------------------------------------------------------------------------
// Requirements
// ------------------------------------------------------------------------------

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

// ------------------------------------------------------------------------------
// Helpers
// ------------------------------------------------------------------------------

/**
 * Check whether the given node is an well-known element or not.
 * @param {ASTNode} node The element node to check.
 * @returns {boolean} `true` if the name is an well-known element name.
 */
function isWellKnownElement (node) {
  if (
    (!utils.isHtmlElementNode(node) && !utils.isSvgElementNode(node)) ||
    utils.isHtmlWellKnownElementName(node.rawName) ||
    utils.isSvgWellKnownElementName(node.rawName)
  ) {
    return true
  }
  return false
}

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

module.exports = {
  meta: {
    type: 'problem',
    docs: {
      description: 'require control the display of the content inside `<transition>`',
      categories: ['vue3-essential'],
      url: 'https://eslint.vuejs.org/rules/require-v-if-inside-transition.html'
    },
    fixable: null,
    schema: [],
    messages: {
      expected: 'The element inside `<transition>` is expected to have a `v-if` or `v-show` directive.'
    }
  },

  create (context) {
    /**
     * Check if the given element has display control.
     * @param {VElement} element The element node to check.
     */
    function verifyInsideElement (element) {
      if (utils.isCustomComponent(element)) {
        return
      }
      if (!isWellKnownElement(element)) {
        return
      }
      if (!utils.hasDirective(element, 'if') && !utils.hasDirective(element, 'show')) {
        context.report({
          node: element.startTag,
          loc: element.startTag.loc,
          messageId: 'expected'
        })
      }
    }

    return utils.defineTemplateBodyVisitor(context, {
      "VElement[name='transition'] > VElement" (node) {
        if (node.parent.children[0] !== node) {
          return
        }
        verifyInsideElement(node)
      }
    })
  }
}