Function resolveToJSON

packages/react-client/src/ReactFlightReplyClient.js:357–859

(
    this:
      | {+[key: string | number]: ReactServerValue}
      | $ReadOnlyArray<ReactServerValue>,
    key: string,
    value: ReactServerValue,
  )

  }

  function resolveToJSON(
    this:
      | {+[key: string | number]: ReactServerValue}
      | $ReadOnlyArray<ReactServerValue>,
    key: string,
    value: ReactServerValue,
  ): ReactJSONValue {
    const parent = this;

    if (__DEV__) {
      if (key === __PROTO__) {
        console.error(
          'Expected not to serialize an object with own property `__proto__`. When parsed this property will be omitted.%s',
          describeObjectForErrorMessage(parent, key),
        );
      }
    }

    // Make sure that `parent[key]` wasn't JSONified before `value` was passed to us
    if (__DEV__) {
      // $FlowFixMe[incompatible-use]
      const originalValue = parent[key];
      if (
        typeof originalValue === 'object' &&
        originalValue !== value &&
        !(originalValue instanceof Date)
      ) {
        if (objectName(originalValue) !== 'Object') {
          console.error(
            'Only plain objects can be passed to Server Functions from the Client. ' +
              '%s objects are not supported.%s',
            objectName(originalValue),
            describeObjectForErrorMessage(parent, key),
          );
        } else {
          console.error(
            'Only plain objects can be passed to Server Functions from the Client. ' +
              'Objects with toJSON methods are not supported. Convert it manually ' +
              'to a simple value before passing it to props.%s',
            describeObjectForErrorMessage(parent, key),
          );
        }
      }
    }

    if (value === null) {
      return null;
    }

    if (typeof value === 'object') {
      switch ((value: any).$$typeof) {
        case REACT_ELEMENT_TYPE: {
          if (temporaryReferences !== undefined && key.indexOf(':') === -1) {
            // TODO: If the property name contains a colon, we don't dedupe. Escape instead.
            const parentReference = writtenObjects.get(parent);
            if (parentReference !== undefined) {
              // If the parent has a reference, we can refer to this object indirectly
              // through the property name inside that parent.