(Medium) Why Small Modules Matter - End Result

EndResult.js

const readFileAsJSON = require("./read-file");
const writeFileToJSON = require("./write-file");
const flattenArray = require("flatten-array");

module.exports = function flattenArrayInsideFile(fileName) {
  return readFileAsJSON(fileName)
    .then(function(parsedContent) {
      const flattenedArray = flattenArray(parsedContent);
      return writeFileToJSON(fileName, flattenedArray);
    })
    .then(function() {
      console.log("Done!");
    });
};

// async/await
module.exports = async function flattenArrayInsideFile(fileName) {
  const parsedContent = await readFileAsJSON(fileName);
  const flattenedArray = flattenArray(parsedContent);
  await writeFileToJSON(fileName, flattenedArray);
  console.log("Done!");
};

What do you think of this idea?

update-file

const readFileAsJSON = require("./read-file");
const writeFileToJSON = require("./write-file");

module.exports = function updateFileAsJSON(fileName, transformation) {
  return readFileAsJSON(fileName)
    .then(function(parsedContent) {
      return writeFileToJSON(fileName, transformation(parsedContent));
    });
};

flatten-array-inside-file

const updateFileAsJSON = require("./update-file");
const flattenArray = require("flatten-array");

module.exports = function flattenArrayInsideFile(fileName) {
  return updateFileAsJSON(fileName, flattenArray)
    .then(function() {
      console.log("Done!");
    });
};