The Nightwatch test runner supports a number of run-time options to be passed to. To view all, run the following:

nightwatch --help


Name Shortname default description
Main options
--env -e default Which testing environment to use - defined in nightwatch.json
--config -c ./nightwatch.json Path to configuration file; `nightwatch.conf.js` or `nightwatch.json` are read by default if present. Check the [Configuration](/gettingstarted/configuration/) section.
--test -t Runs only the specified test suite/module. By default the runner will attempt to run all tests in the src_folders settings folder(s) and their subfolders.
--testcase Used only together with `--test`. Runs the specified testcase from the current suite/module.
--mocha Set the test runner to use Mocha.
--timeout Set the global timeout for assertion retries before an assertion fails. The various timeout values are defined in the [Globals](/gettingstarted/concepts/#using-test-globals) section.
--reuse-browser Use the same browser session to run the individual test suites (serial mode only).
--workers Max number of test files running at the same time (default: CPU cores; e.g. workers=4)
--serial Executes tests serially (disables parallel mode).
--headless Launch the browser (Chrome or Firefox) in headless mode.
--devtools Automatically open devtools when launching the browser (Chrome, Edge, or Safari).
--verbose Shows extended selenium command logging during the session.
--fail-fast Run in "fail-fast" mode: if a test suite cannot be started, the rest will be aborted.
--list-files Shows list of files present in the project.
Tags & filtering
--group -g Runs only the specified group or several (comma separated) of tests (subfolder). Tests are grouped by being placed in the same subfolder.
--skipgroup -s Skip one or several (comma separated) group of tests.
--filter -f Specify a filter (glob expression) as the file name format to use when loading the test files.
--tag -a Filter test modules by tags. Only tests that have the specified tags will be loaded.
--skiptags Skips tests that have the specified tag or tags (comma separated).
--retries Retries failed or errored testcases up to the specified number of times. Retrying a testcase will also retry the `beforeEach` and `afterEach` hooks, if any.
--suiteRetries Retries failed or errored testsuites (test modules) up to the specified number of times. Retrying a testsuite will also retry the `before` and `after` hooks (in addition to the global beforeEach and afterEach respectively), if any are defined on the testsuite.
--reporter -r junit Name of a predefined reporter (e.g. junit) or path to a custom reporter file to use.

The custom reporter interface looks like:
module.exports = {
write(results, options, done) {
--output -o tests_output The location where the JUnit XML reports will be saved.
--open Opens the HTML report generated in the default browser at the end of test run
Component Testing
--debug Automatically pause the test execution after mounting the component and open the Nightwatch debug REPL interface.
--story Allows to specify which story to run from the current file (when using Storybook or JSX written in component story format).
--preview Used to preview a component story/test; automatically pause the test execution after mounting the component.
Info & Help
--help -h Shows this help.
--version -v Shows the version number