pz_expect_js() passes when at least one element matches and the
predicate holds for every match: expr is evaluated as a function
receiving the element, e.g. "el => el.scrollTop > 0". It's the
escape hatch for conditions the catalog doesn't cover. A predicate
that throws is a JavaScript error, not a failed check.
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.
Arguments
- ctx
A paparazzi context.
- expr
A JavaScript function receiving the element, as a string, e.g.
"el => el.scrollTop > 0".- target
A CSS selector string, a
pz_loc()spec, or a list of specs and strings (a union matching any of them).NULLmeans the current context: the pinned set at a scoped context (sopz_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,0checks once.
Examples
if (FALSE) { # paparazzi:::examples_run()
page <- pz_open(pz_example("tasks"))
# The predicate receives each matching element
page |> pz_expect_js("el => el.scrollHeight > el.clientHeight", target = ".task-list")
page |> pz_expect_js("el => el.draggable", target = ".task")
pz_close(page)
}