# `mix demo.record`
[🔗](https://github.com/thenatespack/phoenix_demo/blob/main/lib/mix/tasks/demo.record.ex#L1)

Records every `demo` (see `PhxDemo.Case`) and renders the videos.

    mix demo.record                         # every demo under test/
    mix demo.record test/demos/posts_demo_test.exs
    mix demo.record test/demos/posts_demo_test.exs:5 --gif
    mix demo.record --render-only tmp/demos/my_app_web-demos-posts_demo/create-a-post

It runs `mix test --only phx_demo <paths>` with `MIX_ENV=test`, then,
after the run finishes (Playwright writes the video when the browser
context closes), renders each recorded demo with `PhxDemo.Render`.

Demos that fail are still rendered (handy for debugging), but the task
exits non-zero.

## Options

  * `--gif`: also render a GIF
  * `--no-mp4`: skip the MP4
  * `--no-render`: only record
  * `--render-only DIR`: skip recording and render an existing demo
    directory (repeatable)
  * `--update-baselines`: save this run's scene screenshots as the new
    drift baselines (see `PhxDemo.Drift`)
  * `--no-drift`: skip the visual drift check

Visual drift never fails the task. It prints a warning (and a `::warning`
annotation on GitHub Actions) with a diff image.

Demo files are ordinary ExUnit test files (`*_test.exs`). Keep them out of
your normal `mix test` run with `ExUnit.start(exclude: [:phx_demo])` in
test/test_helper.exs. This task overrides that with `--only phx_demo`.

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*Consult [api-reference.md](api-reference.md) for complete listing*