test-runner.js

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

// Setup babel so all future `require` calls are run through it
require("babel-register")({
    // Override babel's default behaviour of ignoring all `node_modules`
    ignore: false,
    only: [
        // Include all js/jsx files in ./src
        "./src/**/*",
        // We have a node_module called citymapper-js that requires babel transpilation
        /citymapper-js/,
    ],
});

process.argv.slice(2).forEach((arg) => {
    glob(arg, (er, files) => {
        if (er) throw er;
        if (files.length === 0) throw new Error(`test-runner: No files at "${arg}"`);

        files.forEach((file) => {
            const filepath = path.resolve(process.cwd(), file);
            require(filepath);
        });
    });
});