Skip all testthat tests when condition not met

Question

What is the proper way to skip all tests in the test directory of an R package when using testthat/devtools infrastructure? For example, if there is no connection to a database and all the tests rely on that connection, do I need to write a skip in all the files individually or can I write a single skip somewhere?

I have a standard package setup that looks like

mypackage/

... # other package stuff

tests/

testthat.R

testthat/

test-thing1.R

test-thing2.R

At first I thought I could put a test in the testthat.R file like

## in testthat.R
library(testthat)
library(mypackage)

fail_test <- function() FALSE
if (fail_test()) test_check("package")

but, that didn't work and it looks like calling devtools::test() just ignores that file. I guess an alternative would be to store all the tests in another directory, but is there a better solution?

In that example, you would need `if( fail_test() )` ... – Thomas Jan 09 '16 at 11:10 — Thomas, Jan 09 '16 at 11:10

score 7 · Answer 1 · answered Jul 08 '17 at 21:43

The Skipping a test section in the R Packages book covers this use case. Essentially, you write a custom function that checks whatever condition you need to check -- whether or not you can connect to your database -- and then call that function from all tests that require that condition to be satisfied.

Example, parroted from the book:

skip_if_no_db <- function() {
  if (db_conn()) {
    skip("API not available")
  }
}

test_that("foo api returns bar when given baz", {
  skip_if_no_db()
  ...
})

I've found this approach more useful than a single switch to toggle off all tests since I tend to have a mix of test that do and don't rely on whatever condition I'm checking and I want to always run as many tests as possible.

Should you put this in all tests? Is there some way to run it at the "top level" only once? — NelsonGon, Jun 19 '20 at 05:54
Updated link: https://r-pkgs.org/testing-advanced.html#when-testing-gets-hard — colej1390, Feb 16 '23 at 15:33

score 1 · Answer 2 · answered Feb 06 '16 at 19:10

Maybe you may organize tests in subdirectories, putting conditional directory inclusion in a parent folder test:

Consider 'tests' in testthat package. In particular, this one looks interesting:

test-test_dir.r that includes 'test_dir' subdirectory

I do not see here nothing that recurses subdirectories in test scan:

test_dir

Skip all testthat tests when condition not met

2 Answers2