Record, replay and rerun¶

Experimental: This feature is not yet stable

Enable with: Add [experimental] with record = true to ~/.config/nextest/config.toml, or set NEXTEST_EXPERIMENTAL_RECORD=1 in the environment
Tracking issue: TBD

Nextest supports recording test runs to rerun failing tests and to replay them later. Recorded runs are stored locally in the system cache.

Recorded test runs capture:

Test statuses (pass, fail, etc) and durations.
Outputs for all tests, both failing and successful. (If --no-capture is passed in at the time the run is recorded, test output cannot be captured.)

Use cases¶

Rerunning tests that failed or were not run in the past, with the goal being to iteratively converge towards a successful test run.
Replaying test runs, including those that might have aged past terminal scrollback.

In the future, it will be possible to export replayed test runs in various formats such as JUnit and libtest-json output.

To enable recording in user configuration:

Enabling recording in ~/.config/nextest/config.toml

[experimental]
record = true

[record]
enabled = true

Now, all future cargo nextest run instances will automatically be recorded.

Rerunning failed tests — iteratively converge towards a successful test run.
Replaying test runs — replay recorded runs, including with different reporter options.
Portable recordings — export and share recordings across machines.
Managing recorded runs — list, prune, and configure the record store.