Expect elements to be in the viewport

pz_expect_in_viewport() passes when at least one element matches and every match overlaps the viewport: its bounding box crosses the visible area by any amount. Elements entirely above, below, or beside the fold fail; visibility itself is a separate expectation, pz_expect_visible().

Outside of testthat, a failure aborts with a classed error of class "paparazzi_expectation_failure"; inside testthat, the failure is reported as a test failure instead. See pz_expect_exists() for the retry, timeout, and bridge behavior shared by all expectations.

Usage

pz_expect_in_viewport(ctx, target = NULL, ..., not = FALSE, timeout = NULL)

Arguments

ctx

A paparazzi context.

target

A CSS selector string, a pz_loc() spec, or a list of specs and strings (a union matching any of them). NULL means the current context: the pinned set at a scoped context (so pz_expect_exists() on one trivially passes while the scope is live), the page body at the root.

...

Checked empty; reserved for future use.

not

Invert the check.

timeout

Seconds to wait for the expectation to pass; NULL (default) uses the session default, 0 checks once.

Value

ctx, invisibly.

Examples

if (FALSE) { # paparazzi:::examples_run()
page <- pz_open(pz_example("tasks"), height = 500)

# The last task is inside the scrolling list, below its visible area
last_task <- pz_loc(".task", which = "last")
page |> pz_expect_in_viewport(target = last_task, not = TRUE)
page |>
  pz_act_scroll(last_task) |>
  pz_expect_in_viewport(target = last_task)
pz_close(page)
}