[Fix] no-unknown-property: add defaultChecked property

Author: sjarva

CHANGELOG.md

@@ -7,6 +7,7 @@ This change log adheres to standards from [Keep a CHANGELOG](https://keepachange
 
 ### Fixed
 * [`no-unknown-property`]: add properties `onToggle`, `fill`, `as`, and pointer events ([#3385][] @sjarva)
+* [`no-unknown-property`]: add `defaultChecked` property ([#3385][] @sjarva)
 
 [#3385]: https://github.com/jsx-eslint/eslint-plugin-react/issues/3385
 

lib/rules/no-unknown-property.js

@@ -226,7 +226,7 @@ const DOM_PROPERTY_NAMES_TWO_WORDS = [
   'autoCorrect', // https://stackoverflow.com/questions/47985384/html-autocorrect-for-text-input-is-not-working
   'autoSave', // https://stackoverflow.com/questions/25456396/what-is-autosave-attribute-supposed-to-do-how-do-i-use-it
   // React specific attributes https://reactjs.org/docs/dom-elements.html#differences-in-attributes
-  'className', 'dangerouslySetInnerHTML', 'defaultValue', 'htmlFor', 'onChange', 'suppressContentEditableWarning', 'suppressHydrationWarning',
+  'className', 'dangerouslySetInnerHTML', 'defaultValue', 'defaultChecked', 'htmlFor', 'onChange', 'suppressContentEditableWarning', 'suppressHydrationWarning',
 ];
 
 const DOM_PROPERTIES_IGNORE_CASE = ['charset'];

tests/lib/rules/no-unknown-property.js

@@ -56,6 +56,7 @@ ruleTester.run('no-unknown-property', rule, {
     { code: '<input type="checkbox" checked={checked} disabled={disabled} id={id} onChange={onChange} />' },
     // React related attributes
     { code: '<div onPointerDown={this.onDown} onPointerUp={this.onUp} />' },
+    { code: '<input type="checkbox" defaultChecked={this.state.checkbox} />' },
     // Case ignored attributes, for `charset` discussion see https://github.com/jsx-eslint/eslint-plugin-react/pull/1863
     { code: '<meta charset="utf-8" />;' },
     { code: '<meta charSet="utf-8" />;' },