Function defaultEncodeFormAction

packages/react-client/src/ReactFlightReplyClient.js:943–992

(
  this: any => Promise<any>,
  identifierPrefix: string,
)

}

function defaultEncodeFormAction(
  this: any => Promise<any>,
  identifierPrefix: string,
): ReactCustomFormAction {
  const referenceClosure = knownServerReferences.get(this);
  if (!referenceClosure) {
    throw new Error(
      'Tried to encode a Server Action from a different instance than the encoder is from. ' +
        'This is a bug in React.',
    );
  }
  let data: null | FormData = null;
  let name;
  const boundPromise = referenceClosure.bound;
  if (boundPromise !== null) {
    let thenable = boundCache.get(referenceClosure);
    if (!thenable) {
      const {id, bound} = referenceClosure;
      thenable = encodeFormData({id, bound});
      boundCache.set(referenceClosure, thenable);
    }
    if (thenable.status === 'rejected') {
      throw thenable.reason;
    } else if (thenable.status !== 'fulfilled') {
      throw thenable;
    }
    const encodedFormData = thenable.value;
    // This is hacky but we need the identifier prefix to be added to
    // all fields but the suspense cache would break since we might get
    // a new identifier each time. So we just append it at the end instead.
    const prefixedData = new FormData();
    // $FlowFixMe[prop-missing]
    encodedFormData.forEach((value: string | File, key: string) => {
      // $FlowFixMe[incompatible-call]
      prefixedData.append('$ACTION_' + identifierPrefix + ':' + key, value);
    });
    data = prefixedData;
    // We encode the name of the prefix containing the data.
    name = '$ACTION_REF_' + identifierPrefix;
  } else {
    // This is the simple case so we can just encode the ID.
    name = '$ACTION_ID_' + referenceClosure.id;
  }
  return {
    name: name,
    method: 'POST',
    encType: 'multipart/form-data',
    data: data,
  };
}

function customEncodeFormAction(
  reference: any => Promise<any>,