preinitModule() — react Function Reference

Source Code

packages/react-dom/src/shared/ReactDOMFloat.js lines 262–333

export function preinitModule(href: string, options?: ?PreinitModuleOptions) {
  if (__DEV__) {
    let encountered = '';
    if (typeof href !== 'string' || !href) {
      encountered += ` The \`href\` argument encountered was ${getValueDescriptorExpectingObjectForWarning(
        href,
      )}.`;
    }
    if (options !== undefined && typeof options !== 'object') {
      encountered += ` The \`options\` argument encountered was ${getValueDescriptorExpectingObjectForWarning(
        options,
      )}.`;
    } else if (options && 'as' in options && options.as !== 'script') {
      encountered += ` The \`as\` option encountered was ${getValueDescriptorExpectingEnumForWarning(
        options.as,
      )}.`;
    }
    if (encountered) {
      console.error(
        'ReactDOM.preinitModule(): Expected up to two arguments, a non-empty `href` string and, optionally, an `options` object with a valid `as` property.%s',
        encountered,
      );
    } else {
      const as =
        options && typeof options.as === 'string' ? options.as : 'script';
      switch (as) {
        case 'script': {
          break;
        }

        // We have an invalid as type and need to warn
        default: {
          const typeOfAs = getValueDescriptorExpectingEnumForWarning(as);
          console.error(
            'ReactDOM.preinitModule(): Currently the only supported "as" type for this function is "script"' +
              ' but received "%s" instead. This warning was generated for `href` "%s". In the future other' +
              ' module types will be supported, aligning with the import-attributes proposal. Learn more here:' +
              ' (https://github.com/tc39/proposal-import-attributes)',
            typeOfAs,
            href,
          );
        }
      }
    }
  }
  if (typeof href === 'string') {
    if (typeof options === 'object' && options !== null) {
      if (options.as == null || options.as === 'script') {
        const crossOrigin = getCrossOriginStringAs(
          options.as,
          options.crossOrigin,
        );
        ReactDOMSharedInternals.d /* ReactDOMCurrentDispatcher */
          .M(/* preinitModuleScript */ href, {
            crossOrigin,
            integrity:
              typeof options.integrity === 'string'
                ? options.integrity
                : undefined,
            nonce:
              typeof options.nonce === 'string' ? options.nonce : undefined,
          });
      }
    } else if (options == null) {
      ReactDOMSharedInternals.d /* ReactDOMCurrentDispatcher */
        .M(/* preinitModuleScript */ href);
    }
  }
  // We don't error because preinit needs to be resilient to being called in a variety of scopes
  // and the runtime may not be capable of responding. The function is optimistic and not critical
  // so we favor silent bailout over warning or erroring.
}