paths.js

/* eslint-disable import/no-dynamic-require */
/* eslint-disable global-require */
const path = require('path');
const fs = require('fs');
const url = require('url');

const appDirectory = fs.realpathSync(process.cwd());
const resolveApp = relativePath => path.resolve(appDirectory, relativePath);

const envPublicUrl = process.env.PUBLIC_URL;

function ensureSlash(inputPath, needsSlash) {
    const hasSlash = inputPath.endsWith('/');
    if (hasSlash && !needsSlash) {
        return inputPath.substr(0, inputPath.length - 1);
    }
    if (!hasSlash && needsSlash) {
        return `${inputPath}/`;
    }
    return inputPath;
}

const getPublicUrl = appPackageJson => envPublicUrl || require(appPackageJson).homepage;

// We use `PUBLIC_URL` environment variable or "homepage" field to infer
// "public path" at which the app is served.
// Webpack needs to know it to put the right <script> hrefs into HTML even in
// single-page apps that may serve index.html for nested URLs like /todos/42.
// We can't use a relative path in HTML because we don't want to load something
// like /todos/42/static/js/bundle.7289d.js. We have to know the root.
function getServedPath(appPackageJson) {
    const publicUrl = getPublicUrl(appPackageJson);
    const servedUrl = envPublicUrl || (publicUrl ? url.parse(publicUrl).pathname : '/');
    return ensureSlash(servedUrl, true);
}

module.exports = {
    dotenv: resolveApp('.env'),
    servedPath: getServedPath(resolveApp('package.json')),
};