e.g. for the readr tests after tidyverse/readr@abc64a9

─  checking tests ...
✔  Running ‘first_edition.R’ [13s/13s] (13.4s)
✔  Running ‘second_edition.R’ [13s/13s] (26.6s)

In this case both test files take ~13 seconds to run, which the built in time seems to show but the rcmdcheck time is the sum of the total time to run tests, not the time for the individual test file.

Somewhat rare perhaps because most packages using testthat only have one test file.