@dr.pogodin/react-helmet/build/module/Helmet.js

Thread-safe Helmet for React 19+ and friends

import { c as _c } from "react/compiler-runtime";
import { Children, use, useEffect, useId } from 'react';
import { Context } from './Provider';
import { REACT_TAG_MAP, TAG_NAMES, VALID_TAG_NAMES } from './constants';
import { cloneProps, mergeProps, pushToPropArray } from './utils';
function assertChildType(childType, nestedChildren) {
  if (typeof childType !== 'string') {
    throw Error('You may be attempting to nest <Helmet> components within each other, which is not allowed. Refer to our API for more information.');
  }
  if (!VALID_TAG_NAMES.includes(childType)) {
    throw Error(`Only elements types ${VALID_TAG_NAMES.join(', ')} are allowed. Helmet does not support rendering <${childType}> elements. Refer to our API for more information.`);
  }
  if (!nestedChildren || typeof nestedChildren === 'string' || Array.isArray(nestedChildren)
  // TODO: This piece of the check is wrong when parent is a fragment,
  // and thus children may not be an array of strings.
  // && nestedChildren.every((item) => typeof item === 'string')
  ) return;
  throw Error(`Helmet expects a string as a child of <${childType}>. Did you forget to wrap your children in braces? ( <${childType}>{\`\`}</${childType}> ) Refer to our API for more information.`);
}

/**
 * Given a string key, it checks it against the legacy mapping between supported
 * HTML attribute names and their corresponding React prop names (for the names
 * that are different). If found in the mapping, it prints a warning to console
 * and returns the mapped prop name. Otherwise, it just returns the key as is,
 * assuming it is already a valid React prop name.
 */
function getPropName(key) {
  const res = REACT_TAG_MAP[key];
  if (res) {
    // eslint-disable-next-line no-console
    console.warn(`"${key}" is not a valid JSX prop, replace it by "${res}"`);
  }
  return res ?? key;
}

/**
 * Given children and props of a <Helmet> component, it reduces them to a single
 * props object.
 *
 * TODO: I guess, it should be further refactored, to make it cleaner...
 * though, it should perfectly work as is, so not a huge priority for now.
 */
function reduceChildrenAndProps(props) {
  // NOTE: `props` are clonned, thus it is safe to push additional items to
  // array values of `res`, and to re-assign non-array values of `res`, without
  // the risk to mutate the original `props` object.
  const res = cloneProps(props);

  // TODO: This is a temporary block, for compatibility with legacy library.
  for (const item of Object.values(props)) {
    if (Array.isArray(item)) {
      for (const it of item) {
        // TODO: This condition is actually needed to prevent some test failures,
        // I guess, something is messed up with related types?
        // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
        if (it) {
          for (const key of Object.keys(it)) {
            const p = getPropName(key);
            if (p !== key) {
              it[p] = it[key];
              delete it[key];
            }
          }
        }
      }
    } else if (item && typeof item === 'object') {
      const it = item;
      for (const key of Object.keys(it)) {
        const p = getPropName(key);
        if (p !== key) {
          it[p] = it[key];
          delete it[key];
        }
      }
    }
  }

  // eslint-disable-next-line complexity
  Children.forEach(props.children, child => {
    if (child === undefined || child === null) return;
    if (typeof child !== 'object' || !('props' in child)) {
      throw Error(`"${typeof child}" is not a valid <Helmet> descendant`);
    }
    let nestedChildren;
    const childProps = {};
    if (child.props) {
      for (const [key, value] of Object.entries(child.props)) {
        if (key === 'children') nestedChildren = value;else childProps[getPropName(key)] = value;
      }
    }
    let {
      type
    } = child;
    // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-conversion
    if (typeof type === 'symbol') type = type.toString();
    assertChildType(type, nestedChildren);
    function assertStringChild(child2) {
      if (typeof child2 !== 'string') {
        // TODO: We want to throw, but the legacy code did not, so we won't for
        // now.
        // eslint-disable-next-line no-console
        console.error(`child of ${type} element should be a string`);

        /*
        throw Error(
          // NOTE: assertChildType() above guarantees that `type` is a string,
          // although it is not expressed in a way TypeScript can automatically
          // pick up.
        );
        */
      }
    }
    switch (type) {
      case TAG_NAMES.BASE:
        res.base = childProps;
        break;
      case TAG_NAMES.BODY:
        res.bodyAttributes = childProps;
        break;
      case TAG_NAMES.FRAGMENT:
        mergeProps(res, reduceChildrenAndProps({
          children: nestedChildren
        }));
        break;
      case TAG_NAMES.HTML:
        res.htmlAttributes = childProps;
        break;
      case TAG_NAMES.LINK:
      case TAG_NAMES.META:
        if (nestedChildren) {
          throw Error(`<${type} /> elements are self-closing and can not contain children. Refer to our API for more information.`);
        }
        pushToPropArray(res, type, childProps);
        break;
      case TAG_NAMES.NOSCRIPT:
      case TAG_NAMES.SCRIPT:
        if (nestedChildren !== undefined) {
          assertStringChild(nestedChildren);
          childProps.innerHTML = nestedChildren;
        }
        pushToPropArray(res, type, childProps);
        break;
      case TAG_NAMES.STYLE:
        assertStringChild(nestedChildren);
        childProps.cssText = nestedChildren;
        pushToPropArray(res, type, childProps);
        break;
      case TAG_NAMES.TITLE:
        res.titleAttributes = childProps;
        if (typeof nestedChildren === 'string') res.title = nestedChildren;

        // When title contains {} expressions the children are an array of
        // strings, and other values.
        else if (Array.isArray(nestedChildren)) res.title = nestedChildren.join('');
        break;
      case TAG_NAMES.HEAD:
      default:
        {
          // TODO: Perhaps, we should remove HEAD entry from TAG_NAMES?
          // eslint-disable-next-line @typescript-eslint/no-unused-vars
          const bad = type;
        }
    }
  });
  delete res.children;
  return res;
}
const Helmet = props => {
  const $ = _c(8);
  const context = use(Context);
  if (!context) {
    throw Error("<Helmet> component must be within a <HelmetProvider> children tree");
  }
  const id = useId();
  context.update(id, reduceChildrenAndProps(props));
  let t0;
  if ($[0] !== context || $[1] !== id || $[2] !== props) {
    t0 = () => {
      context.update(id, reduceChildrenAndProps(props));
      context.clientApply();
    };
    $[0] = context;
    $[1] = id;
    $[2] = props;
    $[3] = t0;
  } else {
    t0 = $[3];
  }
  useEffect(t0);
  let t1;
  let t2;
  if ($[4] !== context || $[5] !== id) {
    t1 = () => () => {
      context.update(id, undefined);
      context.clientApply();
    };
    t2 = [context, id];
    $[4] = context;
    $[5] = id;
    $[6] = t1;
    $[7] = t2;
  } else {
    t1 = $[6];
    t2 = $[7];
  }
  useEffect(t1, t2);
  return null;
};
export default Helmet;
//# sourceMappingURL=Helmet.js.map