test.js

function main(sources) {
  const request$ = sources.ACTION
    .filter(action => action.type === ActionTypes.REQUESTED_USER_REPOS)
    .map(action => action.payload.user)
    .map(user => {
      url: `https://api.github.com/users/${user}/repos`,
      category: 'users'
    })

  const action$ = sources.HTTP
    .select('users')
    .flatten()
    .map(receiveUserRepos.bind(null, user))

  return {
    ACTION: action$,
    HTTP: request$
  };
}