// import settings from default config file let properties = null; const originalConfigFn = require('./karma.conf.js'); originalConfigFn({ set: function (arg) { properties = arg; }, }); // pass `--grep '[live data]'` to mocha to only run live data tests properties.client.args = ['--grep', '[live data]]']; // export settings module.exports = function (config) { config.set(properties); };