Testthat local_mocked_bindings when not developing a package

Question

I'm developing a shiny app and using testthat for unit tests. I have a folder with test that I run with testthat::test_dir. However, I can't figure out how to use mocking features because I get errors that I'm not in a package. Example: source file with functions:

base_fn <- function(){
  0
}

mocking_result <- function(){
  1
}

My test:

test_that("Mocking a function works",{
  local_mocked_bindings(base_fn = mocking_result)
  
  expect_equal(base_fn(), 1)

})

I keep getting an error Error in dev_package(): No packages loaded with pkgload. I've tried setting the .package argument to NA, NULL, "base", no help. Can I use local_mocked_bindings if I don't want to format everything as a package? I've figured out I can use with_mock to achieve this, but from what I gather that function is superseded so I don't want it to become unusable in the future.

Answer 1

As I was facing the same issue, I asked the question directly on the testthat package repo, and the answer is that

those functions only work inside a package sorry. I think the easiest way to solve your problem would be to put your R scripts in R/ directory and your tests in tests/testthat/ directory and add a minimal DESCRIPTION