test_that_cli {cli} | R Documentation |
Test cli output with testthat
Description
Use this function in your testthat test files, to test cli output. It requires testthat edition 3, and works best with snapshot tests.
Usage
test_that_cli(
desc,
code,
configs = c("plain", "ansi", "unicode", "fancy"),
links = NULL
)
Arguments
desc |
Test description, passed to |
code |
Test code, it is modified to set up the cli config, and
then passed to |
configs |
cli configurations to test |
links |
Whether to run the code with various hyperlinks allowed.
If
|
Details
test_that_cli()
calls testthat::test_that()
multiple times, with
different cli configurations. This makes it simple to test cli output
with and without ANSI colors, with and without Unicode characters.
Currently available configurations:
-
plain
: no ANSI colors, ASCII characters only. -
ansi
: ANSI colors, ASCII characters only. -
unicode
: no ANSI colors, Unicode characters. -
fancy
; ANSI colors, Unicode characters.
See examples below and in cli's own tests, e.g. in https://github.com/r-lib/cli/tree/main/tests/testthat and the corresponding snapshots at https://github.com/r-lib/cli/tree/main/tests/testthat/_snaps
Important note regarding Windows
Because of base R's limitation to record Unicode characters on Windows, we suggest that you record your snapshots on Unix, or you restrict your tests to ASCII configurations.
Unicode tests on Windows are automatically skipped by testthat currently.
Examples
# testthat cannot record or compare snapshots when you run these
# examples interactively, so you might want to copy them into a test
# file
# Default configurations
cli::test_that_cli("success", {
testthat::local_edition(3)
testthat::expect_snapshot({
cli::cli_alert_success("wow")
})
})
# Only use two configurations, because this output does not have colors
cli::test_that_cli(configs = c("plain", "unicode"), "cat_bullet", {
testthat::local_edition(3)
testthat::expect_snapshot({
cli::cat_bullet(letters[1:5])
})
})
# You often need to evaluate all cli calls of a test case in the same
# environment. Use `local()` to do that:
cli::test_that_cli("theming", {
testthat::local_edition(3)
testthat::expect_snapshot(local({
cli::cli_div(theme = list(".alert" = list(before = "!!! ")))
cli::cli_alert("wow")
}))
})