Hydra is a typst package allowing you to easily display the heading like elements anywhere in your document. In short, it will show you the currently active element only when it is not visible.

Some of hydra's features rely on the size of the top-margin, if you use a different page size than a4 or a custom top margin for your pages, make sure to configure hydra, otherwise those cheks may not work.

#import "@preview/hydra:0.3.0": hydra

#set page(header: hydra() + line(length: 100%))
#set heading(numbering: "1.1")
#show heading.where(level: 1): it => pagebreak(weak: true) + it

= Introduction
#lorem(750)

= Content
== First Section
#lorem(500)
== Second Section
#lorem(250)
== Third Section
#lorem(500)

= Annex
#lorem(10)

For a more in-depth description of hydra's functionality and the reference read its manual.

This package serves as my real-world test for typst-test, it is not required for contributions, but encouraged as it speeds up the review process.

Other than that tests can be run using the following command structure for each test:

test=...
typst --root . "tests/typ/${test}.typ" "tests/out/${test}/{n}.png"
# some command to compare images in tests/ref/${test} and tests/out/${test}

Furthermore, I use just and nushell to run common commands. It's once again not required, as I'll generate those myself if you don't on a PR, but if you already use both you can run the example and manual generation using just gen.