'use strict';
const React = require('react');
const ReactDOM = require('react-dom');
const ReactDOMClient = require('react-dom/client');
const assertConsoleErrorDev =
require('internal-test-utils').assertConsoleErrorDev;
function expectWarnings(tags, warnings = [], withoutStack = 0) {
tags = [...tags];
warnings = [...warnings];
document.removeChild(document.documentElement);
document.appendChild(document.createElement('html'));
document.documentElement.innerHTML = '<head></head><body></body>';
let element = null;
const containerTag = tags.shift();
let container;
switch (containerTag) {
case '#document':
container = document;
break;
case 'html':
container = document.documentElement;
break;
case 'body':
container = document.body;
break;
case 'head':
container = document.head;
break;
case 'svg':
container = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
break;
default:
container = document.createElement(containerTag);
break;
}
while (tags.length) {
const Tag = tags.pop();
if (Tag === '#text') {
element = 'text';
} else {
element = <Tag>{element}</Tag>;
}
}
const root = ReactDOMClient.createRoot(container);
ReactDOM.flushSync(() => {
root.render(element);
});
if (warnings.length) {
assertConsoleErrorDev(
warnings,
withoutStack > 0 ? {withoutStack} : undefined,
);
}
root.unmount();
}
describe('validateDOMNesting', () => {
it('allows valid nestings', () => {
expectWarnings(['table', 'tbody', 'tr', 'td', 'b']);
expectWarnings(['body', 'datalist', 'option']);
expectWarnings(['div', 'a', 'object', 'a']);
expectWarnings(['div', 'p', 'button', 'p']);
expectWarnings(['p', 'svg', 'foreignObject', 'p']);
expectWarnings(['html', 'body', 'div']);
expectWarnings(['div', 'ul', 'ul', 'li']);
expectWarnings(['div', 'label', 'div']);
expectWarnings(['div', 'ul', 'li', 'section', 'li']);
expectWarnings(['div', 'ul', 'li', 'dd', 'li']);
});
it('prevents problematic nestings', () => {
expectWarnings(
['a', 'a'],
[
'In HTML, <a> cannot be a descendant of <a>.\n' +
'This will cause a hydration error.\n' +
' in a (at **)',
],
);
expectWarnings(
['form', 'form'],
[
'In HTML, <form> cannot be a descendant of <form>.\n' +
'This will cause a hydration error.\n' +
' in form (at **)',
],
);
expectWarnings(
['p', 'p'],
[
'In HTML, <p> cannot be a descendant of <p>.\n' +
'This will cause a hydration error.\n' +
' in p (at **)',
],
);
expectWarnings(
['table', 'tr'],
[
'In HTML, <tr> cannot be a child of <table>. ' +
'Add a <tbody>, <thead> or <tfoot> to your code to match the DOM tree generated by the browser.\n' +
'This will cause a hydration error.\n' +
' in tr (at **)',
],
);
expectWarnings(
['div', 'ul', 'li', 'div', 'li'],
[
'In HTML, <li> cannot be a descendant of <li>.\n' +
'This will cause a hydration error.\n' +
'\n' +
' <ul>\n' +
'> <li>\n' +
' <div>\n' +
'> <li>\n' +
'\n' +
' in li (at **)',
'<li> cannot contain a nested <li>.\nSee this log for the ancestor stack trace.\n' +
' in li (at **)',
],
);
expectWarnings(
['div', 'html'],
[
'In HTML, <html> cannot be a child of <div>.\n' +
'This will cause a hydration error.\n' +
' in html (at **)',
],
);
expectWarnings(
['body', 'body'],
[
'In HTML, <body> cannot be a child of <body>.\n' +
'This will cause a hydration error.\n' +
' in body (at **)',
],
);
expectWarnings(
['head', 'body'],
[
'In HTML, <body> cannot be a child of <head>.\n' +
'This will cause a hydration error.\n' +
' in body (at **)',
],
);
expectWarnings(
['head', 'head'],
[
'In HTML, <head> cannot be a child of <head>.\n' +
'This will cause a hydration error.\n' +
' in head (at **)',
],
);
expectWarnings(
['html', 'html'],
[
'In HTML, <html> cannot be a child of <html>.\n' +
'This will cause a hydration error.\n' +
' in html (at **)',
],
);
expectWarnings(
['body', 'html'],
[
'In HTML, <html> cannot be a child of <body>.\n' +
'This will cause a hydration error.\n' +
' in html (at **)',
],
);
expectWarnings(
['head', 'html'],
[
'In HTML, <html> cannot be a child of <head>.\n' +
'This will cause a hydration error.\n' +
' in html (at **)',
],
);
expectWarnings(
['svg', 'foreignObject', 'body', 'p'],
[
'In HTML, <body> cannot be a child of <foreignObject>.\n' +
'This will cause a hydration error.\n' +
'\n' +
'> <foreignObject>\n' +
'> <body>\n' +
'\n' +
' in body (at **)',
],
);
});
it('relaxes the nesting rules at the root when the container is a singleton', () => {
expectWarnings(['#document', 'html']);
expectWarnings(['#document', 'body']);
expectWarnings(['#document', 'head']);
expectWarnings(['#document', 'div']);
expectWarnings(['#document', 'meta']);
expectWarnings(['#document', '#text']);
expectWarnings(['html', 'body']);
expectWarnings(['html', 'head']);
expectWarnings(['html', 'div']);
expectWarnings(['html', 'meta']);
expectWarnings(['html', '#text']);
expectWarnings(['body', 'head']);
expectWarnings(['body', 'div']);
expectWarnings(['body', 'meta']);
expectWarnings(['body', '#text']);
});
});