Automatically Split E2E Tasks by File

In almost every codebase, e2e tests are the largest portion of the CI pipeline. Typically, e2e tests are grouped by application so that whenever an application's code changes, all the e2e tests for that application are run. These large groupings of e2e tests make caching and distribution less effective. Also, because e2e tests deal with a lot of integration code, they are at a much higher risk to be flaky.

You could manually address these problems by splitting your e2e tests into smaller tasks, but this requires developer time to maintain and adds additional configuration overhead to your codebase. Or, you could allow Nx to automatically split your Cypress or Playwright e2e tests by file.

Set up

To enable automatically split e2e tasks, you need to turn on inferred tasks for the @nx/cypress or @nx/playwright plugins. Run this command to set up inferred tasks:

This command will register the appropriate plugin in the plugins array of nx.json.

Manual Configuration

If you are already using the @nx/cypress or @nx/playwright plugin, you need to manually add the appropriate configuration to the plugins array of nx.json. The configuration settings can be found on the Cypress or Playwright plugin docs.

Usage

You can view the available tasks in the graph:

You'll see that there are tasks named e2e, e2e-ci and a task for each e2e test file.

Developers can run all e2e tests locally the same way as usual:

You can update your CI pipeline to run e2e-ci, which will automatically run all the inferred tasks for the individual e2e test files. Run it like this:

Benefits

Smaller e2e tasks enable the following benefits:

• Nx's cache can be used for all the e2e tasks that succeeded and only the failed tasks need to be re-run
• Distributed Task Execution allows your e2e tests to be run on multiple machines simultaneously, which reduces the total time of the CI pipeline
• Nx Agents can automatically re-run failed flaky e2e tests on a separate agent without a developer needing to manually re-run the CI pipeline