Macro masonry::assert_render_snapshot

macro_rules! assert_render_snapshot {
    ($test_harness:expr, $name:expr) => { ... };
}

Assert a snapshot of a rendered frame of your app.

This macro takes a test harness and a name, renders the current state of the app, and stores the render as a PNG next to the text, in a ./screenshots/ folder.

If a screenshot already exists, the rendered value is compared against this screenshot. The assert passes if both are equal; otherwise, a diff file is created.

If a screenshot doesn’t exist, the assert will fail; the new screenshot is stored as ./screenshots/<test_name>.new.png, and must be renamed before the assert will pass.