one off script to mixup lodash imports in a project

fix-lodash-imports

#! /usr/bin/env node 

/**
 * ./fix-lodash-imports path/to/file.js
 */

const fs = require('fs');

const loadFile = filepath => fs.readFileSync(filepath, 'utf8');
const writeFile = (filepath, data) => fs.writeFileSync(filepath, data, 'utf8');
const importRegex = /^import ([a-zA-Z]+) from 'lodash\/fp\/\1';$/;

const main = argv => {
    const target = argv[2];

    const file = loadFile(target);
    const lines = file.split('\n');

    const matches = lines.map((data, index) => [index, data]).filter(([, line]) => importRegex.test(line));

    if (matches.length < 1) {
        console.log(`0 matches found in ${target}`);
        return;
    }

    // create list of sub modules
    const subModules = matches.map(([, data]) => importRegex.exec(data)[1]);

    // create new import statement
    const newImport = `import { ${subModules.join(', ')} } from 'lodash/fp';`;

    // naughttttyyy in place splicing
    // replace first import with our shiny new one
    const firstMatch = matches[0];

    if (firstMatch) {
        const pos = firstMatch[0];
        lines.splice(pos, 1, newImport);
    }

    // delete any remaning matches
    const remaning = matches.slice(1);
    // reverse otherwise our match offsets go wrong with each removal
    remaning.reverse().forEach(m => lines.splice(m[0], 1));

    writeFile(target, lines.join('\n'));

    console.log(`${subModules.length} imports splatted down (${remaning.length}--) in ${target}`);
};

main(process.argv);

fix-lodash-imports.md

git grep -l "[a-z] from 'lodash/fp/[a-zA-Z]" | while read line; do ./fix-lodash-imports "$line" ; done