hof thunks: mapping resolutions

hof-thunks-0-mapres-decorator.js

// my-app/api/thunk-utils.js

// ... other decorators and such.

export function mapResolution(mapResFn) {
  return (createThunk) => (params, meta) => async (dispatch, getState) => {
    const res = await dispatch(createThunk(params, meta));
    if (res.error) return res;
    return {
      ...res,
      result: mapResFn(res.result, getState(), params, meta),
    };
  };
}

hof-thunks-1-mapping-that-res.jsx

import { myEndpoint } from 'my-app/api/thunks';
import * as thunk from 'my-app/api/thunk-utils';
// ... other sundry imports.

export default compose(
  connect(
    null,
    (dispatch, ownProps) => ({
      getMyResource: compose(
        thunk.map(dispatch),
        thunk.withParams({
          name: ownProps.name,
          order: 'asc',
        }),
        thunk.then((res, state) => (
          resHasRelated(res)
          ? compose(
            thunk.withParams({ relatedId: res.relatedId }),
            // Now we can clean up the resolution from the related endpoint.
            thunk.mapResolution((relatedRes) => cleanUpRelatedRes(relatedRes))
          )(myRelatedEndpoint)
          : thunk.resolvingWith(() => res)
        ))
      )(myEndpoint),
    })
  )
)(class MyResourceDisplay extends PureComponent {
  // same old, same old...
});