expect_snapshot does not work during `auto_test_package()` when single test file reruns are triggered

[sebkopf]

Apologies upfront, I don't know how to reprex this particular issue but here's how it can be reproduced in a few steps.

In a bare R package, add a file with a simple snapshot test, such as test-example.R below, and run devtools::test() once to create the snapshot.

test_that("produce auto_test issue with snapshots", {
  expect_snapshot(1)
})

Now run auto_test_package(). At first it behaves as I would expect. It runs the tests (or single test in this example) and reruns them when I make code changes in any files in R or src folders. However if I make a change in the test file (test-example.R) and it thus triggers a rerun of only the tests in that file, the paths to the snapshot end up wrong somehow, it tries to re-create the snapshot and the tests fail:

> auto_test_package()
ℹ Loading examplepkg
✔ | F W  S  OK | Context
✔ |          1 | example                                                                                                                                                                                                                                                                

══ Results ═════════════════
[ FAIL 0 | WARN 0 | SKIP 0 | PASS 1 ]
Changed code:  example.R 
Rerunning all tests
✔ | F W  S  OK | Context
✔ |          1 | example                                                                                                                                                                                                                                                                

══ Results ═════════════════
[ FAIL 0 | WARN 0 | SKIP 0 | PASS 1 ]
Rerunning tests:  test-example.R 
✔ | F W  S  OK | Context
✔ |   1      1 | /Users/sk/R/examplepkg/tests/testthat/test-example                                                                     
──────────────────
Warning (/Users/sk/R/examplepkg/tests/testthat/test-example.R:2:3): produce auto_test issue with snapshots
Adding new snapshot:
Code
  1
Output
  [1] 1
──────────────────
Error in brio::write_file(out, path) : 
  Could not open file: /Users/sk/R/examplepkg/tests/testthat/_snaps//Users/sk/R/examplepkg/tests/testthat/test-example.md

I suspect this has something todo with the tests paths of the watcher here but not sure what's going wrong exactly:

testthat/R/auto-test.R

Line 117 in 0fa3269

test_paths = tests,

Session info:

> sessionInfo()
R version 4.3.3 (2024-02-29)
Platform: x86_64-apple-darwin20 (64-bit)
Running under: macOS Sonoma 14.6.1

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib 
LAPACK: /Library/Frameworks/R.framework/Versions/4.3-x86_64/Resources/lib/libRlapack.dylib;  LAPACK version 3.11.0

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

time zone: Europe/Berlin
tzcode source: internal

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1]  testthat_3.2.2

[hadley]

Thanks for filing this bug report! Unfortunately because it hits a combination of features that not many people use and it's likely to be tricky to fix, we don't have the development resources to fix at this time. It's our policy to close such issues to help stay focussed on the biggest problems, but the issue is still indexed by google, so if other people hit it, they'll be able to find it, and we can consider reopen it if it turns out to be a common problem. Thanks for reporting and I'm sorry we couldn't help more 😞.