[R-pkg-devel] Interpret feedback: not write testthat-tests in examples

[Richel Bilderbeek]

Dear R package developers,

I would enjoy some help regarding some feedback I got on my package from a CRAN volunteer, as I am unsure how to interpret this correctly.

This is the feedback I got (I added '[do]'):

> Please [do] not write testthat-tests in your examples.

I wonder if this is about using `testthat` or using tests in general.

To simplify the context, say I wrote a package with a function called `add`, that adds two numbers. My example code would then be something like this:

```
library(testthat)

expect_equal(add(1, 2), 3)
```

The first interpretation is about using `testthat`: maybe I should use base R (`stopifnot`) or another testing library (`testit`) or hand-craft it myself?

The second interpretation is about using tests in example code. I like to actively demonstrate that my code works as expected. I checked the policies regarding examples, and I could not find a rule that I should refrain from doing so.

What is the correct response to this feedback?

Thanks for your guidance, Richel Bilderbeek