replace-module-paths.js

const path = require('path')
const fs = require('fs');

let flavors = process.env.FLAVORS;
flavors = flavors ? [...flavors.split(','), ''] : [];

module.exports = function(originalPath, callingFileName, options) {
    let dirpath = callingFileName.split('/');
    dirpath = dirpath.slice(0, dirpath.length - 1).join('/');

    let expectedPath;
    for (suffix of flavors) {
        const correctSuffix = suffix ? `.${suffix}` : '';
        const pathname = path.resolve(dirpath, `${originalPath}${correctSuffix}.js`);
        const isExist = fs.existsSync(pathname);

        if (isExist) {
            let nextPathName = pathname.split('/');
            nextPathName = nextPathName[nextPathName.length - 1];

            const originalPathArray = originalPath.split('/');
            expectedPath = [
                ...originalPathArray.slice(0, originalPathArray.length - 1),
                nextPathName
            ].join('/');

            break;
        }
    }

    return expectedPath;
}