void-dom-elements-no-children.js 4.0 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('hasown');
  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. /** @type {import('eslint').Rule.RuleModule} */
  42. module.exports = {
  43. meta: {
  44. docs: {
  45. description: 'Disallow void DOM elements (e.g. `<img />`, `<br />`) from receiving children',
  46. category: 'Best Practices',
  47. recommended: false,
  48. url: docsUrl('void-dom-elements-no-children'),
  49. },
  50. messages: {
  51. noChildrenInVoidEl,
  52. },
  53. schema: [],
  54. },
  55. create: (context) => ({
  56. JSXElement(node) {
  57. const elementName = node.openingElement.name.name;
  58. if (!isVoidDOMElement(elementName)) {
  59. // e.g. <div />
  60. return;
  61. }
  62. if (node.children.length > 0) {
  63. // e.g. <br>Foo</br>
  64. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  65. node,
  66. data: {
  67. element: elementName,
  68. },
  69. });
  70. }
  71. const attributes = node.openingElement.attributes;
  72. const hasChildrenAttributeOrDanger = attributes.some((attribute) => {
  73. if (!attribute.name) {
  74. return false;
  75. }
  76. return attribute.name.name === 'children' || attribute.name.name === 'dangerouslySetInnerHTML';
  77. });
  78. if (hasChildrenAttributeOrDanger) {
  79. // e.g. <br children="Foo" />
  80. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  81. node,
  82. data: {
  83. element: elementName,
  84. },
  85. });
  86. }
  87. },
  88. CallExpression(node) {
  89. if (node.callee.type !== 'MemberExpression' && node.callee.type !== 'Identifier') {
  90. return;
  91. }
  92. if (!isCreateElement(context, node)) {
  93. return;
  94. }
  95. const args = node.arguments;
  96. if (args.length < 1) {
  97. // React.createElement() should not crash linter
  98. return;
  99. }
  100. const elementName = 'value' in args[0] ? args[0].value : undefined;
  101. if (!isVoidDOMElement(elementName)) {
  102. // e.g. React.createElement('div');
  103. return;
  104. }
  105. if (args.length < 2 || args[1].type !== 'ObjectExpression') {
  106. return;
  107. }
  108. const firstChild = args[2];
  109. if (firstChild) {
  110. // e.g. React.createElement('br', undefined, 'Foo')
  111. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  112. node,
  113. data: {
  114. element: elementName,
  115. },
  116. });
  117. }
  118. const props = args[1].properties;
  119. const hasChildrenPropOrDanger = props.some((prop) => {
  120. if (!('key' in prop) || !prop.key || !('name' in prop.key)) {
  121. return false;
  122. }
  123. return prop.key.name === 'children' || prop.key.name === 'dangerouslySetInnerHTML';
  124. });
  125. if (hasChildrenPropOrDanger) {
  126. // e.g. React.createElement('br', { children: 'Foo' })
  127. report(context, noChildrenInVoidEl, 'noChildrenInVoidEl', {
  128. node,
  129. data: {
  130. element: elementName,
  131. },
  132. });
  133. }
  134. },
  135. }),
  136. };