void-dom-elements-no-children.js 3.9 KB

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  1. /**
  2. * @fileoverview Prevent void elements (e.g. <img />, <br />) from receiving
  3. * children
  4. * @author Joe Lencioni
  5. */
  6. 'use strict';
  7. const has = require('object.hasown/polyfill')();
  8. const docsUrl = require('../util/docsUrl');
  9. const isCreateElement = require('../util/isCreateElement');
  10. const report = require('../util/report');
  11. // ------------------------------------------------------------------------------
  12. // Helpers
  13. // ------------------------------------------------------------------------------
  14. // Using an object here to avoid array scan. We should switch to Set once
  15. // support is good enough.
  16. const VOID_DOM_ELEMENTS = {
  17. area: true,
  18. base: true,
  19. br: true,
  20. col: true,
  21. embed: true,
  22. hr: true,
  23. img: true,
  24. input: true,
  25. keygen: true,
  26. link: true,
  27. menuitem: true,
  28. meta: true,
  29. param: true,
  30. source: true,
  31. track: true,
  32. wbr: true,
  33. };
  34. function isVoidDOMElement(elementName) {
  35. return has(VOID_DOM_ELEMENTS, elementName);
  36. }
  37. // ------------------------------------------------------------------------------
  38. // Rule Definition
  39. // ------------------------------------------------------------------------------
  40. const noChildrenInVoidEl = 'Void DOM element <{{element}} /> cannot receive children.';
  41. module.exports = {
  42. meta: {
  43. docs: {
  44. description: 'Disallow void DOM elements (e.g. `<img />`, `<br />`) from receiving children',
  45. category: 'Best Practices',
  46. recommended: false,
  47. url: docsUrl('void-dom-elements-no-children'),
  48. },
  49. messages: {
  50. noChildrenInVoidEl,
  51. },
  52. schema: [],
  53. },
  54. create: (context) => ({
  55. JSXElement(node) {
  56. const elementName = node.openingElement.name.name;
  57. if (!isVoidDOMElement(elementName)) {
  58. // e.g. <div />
  59. return;
  60. }
  61. if (node.children.length > 0) {
  62. // e.g. <br>Foo</br>
  63. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  64. node,
  65. data: {
  66. element: elementName,
  67. },
  68. });
  69. }
  70. const attributes = node.openingElement.attributes;
  71. const hasChildrenAttributeOrDanger = attributes.some((attribute) => {
  72. if (!attribute.name) {
  73. return false;
  74. }
  75. return attribute.name.name === 'children' || attribute.name.name === 'dangerouslySetInnerHTML';
  76. });
  77. if (hasChildrenAttributeOrDanger) {
  78. // e.g. <br children="Foo" />
  79. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  80. node,
  81. data: {
  82. element: elementName,
  83. },
  84. });
  85. }
  86. },
  87. CallExpression(node) {
  88. if (node.callee.type !== 'MemberExpression' && node.callee.type !== 'Identifier') {
  89. return;
  90. }
  91. if (!isCreateElement(node, context)) {
  92. return;
  93. }
  94. const args = node.arguments;
  95. if (args.length < 1) {
  96. // React.createElement() should not crash linter
  97. return;
  98. }
  99. const elementName = args[0].value;
  100. if (!isVoidDOMElement(elementName)) {
  101. // e.g. React.createElement('div');
  102. return;
  103. }
  104. if (args.length < 2 || args[1].type !== 'ObjectExpression') {
  105. return;
  106. }
  107. const firstChild = args[2];
  108. if (firstChild) {
  109. // e.g. React.createElement('br', undefined, 'Foo')
  110. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  111. node,
  112. data: {
  113. element: elementName,
  114. },
  115. });
  116. }
  117. const props = args[1].properties;
  118. const hasChildrenPropOrDanger = props.some((prop) => {
  119. if (!prop.key) {
  120. return false;
  121. }
  122. return prop.key.name === 'children' || prop.key.name === 'dangerouslySetInnerHTML';
  123. });
  124. if (hasChildrenPropOrDanger) {
  125. // e.g. React.createElement('br', { children: 'Foo' })
  126. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  127. node,
  128. data: {
  129. element: elementName,
  130. },
  131. });
  132. }
  133. },
  134. }),
  135. };