The Convenience of _.chain Without Importing the World

I’ve been meaning to work out how to maintain the convenience of the Lodash’s _.chain function whilst only including the parts of Lodash that I actually need.

Turns out you can cherry pick the fp version of the functions you need and compose them together with _.flow.

import sortBy from "lodash/fp/sortBy";
import flatMap from "lodash/fp/flatMap";
import uniq from "lodash/fp/uniq";
import reverse from "lodash/fp/reverse";
import flow from "lodash/fp/flow";

const exampleData = [
  {
    happenedAt: "2017-06-15T19:00:00+08:00",
    projects: ["Project One"],
  },
  {
    happenedAt: "2017-06-16T19:00:00+08:00",
    projects: ["Project One", "Project Two"],
  },
];

const listOfProjectsByTime = (entries) => {
  return flow(
    sortBy("happenedAt"),
    reverse,
    flatMap("projects"),
    uniq
  )(entries);
};

You can read more in Lodash’s FP Guide.

∙ Programming