Globally replace mass-lodash imports

replace.js

const { exec } = require("child_process");
const fs = require("fs");

const script = exec(
  "grep -lir --exclude-dir={android,ios,node_modules,coverage} \"import _ from 'lodash'\" . | grep -v .map"
);

let filesToUpdate;

const fixNextFile = () => {
  if (filesToUpdate.length) {
    const filename = filesToUpdate.shift();
    let fileContents = fs.readFileSync(filename, {
      encoding: "utf8"
    });
    let lodashRegex = /(_\.)([a-zA-Z]+)/g;
    let lodashFns = [];

    match = lodashRegex.exec(fileContents);
    while (match != null) {
      const wholeRef = match[0];
      fileContents = fileContents.replace(wholeRef, wholeRef.substr(2));
      lodashFns.push(match[2]);
      match = lodashRegex.exec(fileContents);
    }

    lodashFns = lodashFns.filter(
      (item, pos) => lodashFns.indexOf(item) === pos
    );

    if (lodashFns.length) {
    fileContents = fileContents.replace(
      "import _ from 'lodash'",
      `import { ${lodashFns.join(",")} } from 'lodash'`
    );

    console.log(`Analysis of ${filename}`);
    console.log(`Lodash functions detected: ${lodashFns.join(",")}`);
    console.log("-----");
    
    fs.writeFileSync(filename, fileContents, { encoding: "utf-8" });
    } else {
      console.log('Could not find lodash usage.')
    }
    fixNextFile();
  }
};

script.stdout.on("data", function(data) {
  filesToUpdate = data
    .split("\n")
    .filter(val => !!val)
    .filter(val => !val.includes("lodash-fix"));

  fixNextFile();
});