`expect_snapshot` and friends suggest incorrect review and accept code when `variant` is not NULL

[mrcaseb]

Let's start with what I am observing during package development:

When passing a variant to expect_snapshot() or expect_snapshot_value() the printed snapshot_hint prints incorrect files as running the suggested code results in #> No snapshots to update.
The printed files are the name of the test file and it misses the variant directory.

Since I don't really know the internals of testthat, I had a hard time creating a reprex. I went off of #1545 and was asked by Hadley to file a new issue in #1545 (comment)

library(testthat)
# I need test_dir as path for snapshot_review
test_dir <- withr::local_tempdir()
# and I need snap_dir as path where snapshots should be saved to
snap_dir <- file.path(test_dir, "_snaps")
snapper <- testthat:::local_snapshotter(snap_dir)

snapper$start_file("test", "test")
test_that("test", {
  local_edition(3)
  expect_snapshot_value("a", variant = "barret")
})
#> ── Warning: test ───────────────────────────────────────────────────────────────
#> Adding new snapshot for variant 'barret':
#> "a"
#> Test passed with 1 success 🎉.
snapper$end_file()

list.files(test_dir, recursive = TRUE)
#> [1] "_snaps/barret/test.md"

snapper$start_file("test", "test")
test_that("test", {
  local_edition(3)
  expect_snapshot_value("b", variant = "barret")
})
#> ── Failure: test ───────────────────────────────────────────────────────────────
#> Snapshot of "b" has changed (variant 'barret'):
#>     old | new    
#> [1] a   - b   [1]
#> * Run `testthat::snapshot_accept("test")` to accept the change.
#> * Run `testthat::snapshot_review("test")` to review the change.
#> Error:
#> ! Test failed with 1 failure and 0 successes.
snapper$end_file()
list.files(test_dir, recursive = TRUE)
#> [1] "_snaps/barret/test.md"     "_snaps/barret/test.new.md"

# The suggested code: doesn't work
snapshot_review("test", path = test_dir)
#> No snapshots to update.

# The following two work as expected

# what snapshot_meta expects us to pass
snapshot_review("barret/", path = test_dir)

# also works because it checks all recursive dirs? 
# I wonder if this would let us review more than we wanted if 
# there were other changed snapshots in other sub directories.
snapshot_review(path = test_dir)

^{Created on 2026-02-19 with reprex v2.1.1}

Session info

sessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value
#>  version  R version 4.5.2 Patched (2025-10-31 r88977)
#>  os       macOS Tahoe 26.2
#>  system   aarch64, darwin20
#>  ui       X11
#>  language en
#>  collate  en_US.UTF-8
#>  ctype    en_US.UTF-8
#>  tz       Europe/Berlin
#>  date     2026-02-19
#>  pandoc   3.6.3 @ /Applications/RStudio.app/Contents/Resources/app/quarto/bin/tools/aarch64/ (via rmarkdown)
#>  quarto   1.7.33 @ /usr/local/bin/quarto
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version date (UTC) lib source
#>  brio          1.1.5   2024-04-24 [1] CRAN (R 4.5.0)
#>  cli           3.6.5   2025-04-23 [1] CRAN (R 4.5.0)
#>  crayon        1.5.3   2024-06-20 [1] CRAN (R 4.5.0)
#>  desc          1.4.3   2023-12-10 [1] CRAN (R 4.5.0)
#>  diffobj       0.3.6   2025-04-21 [1] CRAN (R 4.5.0)
#>  diffviewer    0.1.2   2024-06-12 [1] CRAN (R 4.5.0)
#>  digest        0.6.39  2025-11-19 [1] CRAN (R 4.5.2)
#>  evaluate      1.0.5   2025-08-27 [1] CRAN (R 4.5.0)
#>  fastmap       1.2.0   2024-05-15 [1] CRAN (R 4.5.0)
#>  fs            1.6.6   2025-04-12 [1] CRAN (R 4.5.0)
#>  glue          1.8.0   2024-09-30 [1] CRAN (R 4.5.0)
#>  htmltools     0.5.9   2025-12-04 [1] CRAN (R 4.5.2)
#>  httpuv        1.6.16  2025-04-16 [1] CRAN (R 4.5.0)
#>  jsonlite      2.0.0   2025-03-27 [1] CRAN (R 4.5.0)
#>  knitr         1.51    2025-12-20 [1] CRAN (R 4.5.2)
#>  later         1.4.6   2026-02-13 [1] CRAN (R 4.5.2)
#>  lifecycle     1.0.5   2026-01-08 [1] CRAN (R 4.5.2)
#>  magrittr      2.0.4   2025-09-12 [1] CRAN (R 4.5.0)
#>  mime          0.13    2025-03-17 [1] CRAN (R 4.5.0)
#>  otel          0.2.0   2025-08-29 [1] CRAN (R 4.5.0)
#>  pillar        1.11.1  2025-09-17 [1] CRAN (R 4.5.0)
#>  pkgload       1.5.0   2026-02-03 [1] CRAN (R 4.5.2)
#>  promises      1.5.0   2025-11-01 [1] CRAN (R 4.5.0)
#>  R6            2.6.1   2025-02-15 [1] CRAN (R 4.5.0)
#>  Rcpp          1.1.1   2026-01-10 [1] CRAN (R 4.5.2)
#>  reprex        2.1.1   2024-07-06 [1] CRAN (R 4.5.0)
#>  rlang         1.1.7   2026-01-09 [1] CRAN (R 4.5.2)
#>  rmarkdown     2.30    2025-09-28 [1] CRAN (R 4.5.0)
#>  rprojroot     2.1.1   2025-08-26 [1] CRAN (R 4.5.0)
#>  rstudioapi    0.18.0  2026-01-16 [1] CRAN (R 4.5.2)
#>  sessioninfo   1.2.3   2025-02-05 [1] CRAN (R 4.5.0)
#>  shiny         1.12.1  2025-12-09 [1] CRAN (R 4.5.2)
#>  testthat    * 3.3.2   2026-01-11 [1] CRAN (R 4.5.2)
#>  vctrs         0.7.1   2026-01-23 [1] CRAN (R 4.5.2)
#>  waldo         0.6.2   2025-07-11 [1] CRAN (R 4.5.0)
#>  withr         3.0.2   2024-10-28 [1] CRAN (R 4.5.0)
#>  xfun          0.56    2026-01-18 [1] CRAN (R 4.5.2)
#>  xtable        1.8-4   2019-04-21 [1] CRAN (R 4.5.0)
#>  yaml          2.3.12  2025-12-10 [1] CRAN (R 4.5.2)
#> 
#>  [2] /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library
#>  * ── Packages attached to the search path.
#> 
#> ──────────────────────────────────────────────────────────────────────────────

[mrcaseb]

Adding a reprex here that creats two separate variants in order to show that the empty snapshot_review will let us review all changed snapshots across all variants (but I guess that's expected behavior?)

library(testthat)
# I need test_dir as path for snapshot_review
test_dir <- withr::local_tempdir()
# and I need snap_dir as path where snapshots should be saved to
snap_dir <- file.path(test_dir, "_snaps")
snapper <- testthat:::local_snapshotter(snap_dir)

snapper$start_file("test", "test")
test_that("test", {
  local_edition(3)
  expect_snapshot_value("a", variant = "barret")
  expect_snapshot_value("x", variant = "another")
})
#> ── Warning: test ───────────────────────────────────────────────────────────────
#> Adding new snapshot for variant 'barret':
#> "a"
#> ── Warning: test ───────────────────────────────────────────────────────────────
#> Adding new snapshot for variant 'another':
#> "x"
#> Test passed with 2 successes 🥳.
snapper$end_file()

list.files(test_dir, recursive = TRUE)
#> [1] "_snaps/another/test.md" "_snaps/barret/test.md"

snapper$start_file("test", "test")
test_that("test", {
  local_edition(3)
  expect_snapshot_value("b", variant = "barret")
  expect_snapshot_value("y", variant = "another")
})
#> ── Failure: test ───────────────────────────────────────────────────────────────
#> Snapshot of "b" has changed (variant 'barret'):
#>     old | new    
#> [1] a   - b   [1]
#> * Run `testthat::snapshot_accept("test")` to accept the change.
#> * Run `testthat::snapshot_review("test")` to review the change.
#> ── Failure: test ───────────────────────────────────────────────────────────────
#> Snapshot of "y" has changed (variant 'another'):
#>     old | new    
#> [1] x   - y   [1]
#> * Run `testthat::snapshot_accept("test")` to accept the change.
#> * Run `testthat::snapshot_review("test")` to review the change.
#> Error:
#> ! Test failed with 2 failures and 0 successes.
snapper$end_file()
list.files(test_dir, recursive = TRUE)
#> [1] "_snaps/another/test.md"     "_snaps/another/test.new.md"
#> [3] "_snaps/barret/test.md"      "_snaps/barret/test.new.md"

# The suggested code: doesn't work
snapshot_review("test", path = test_dir)
#> No snapshots to update.

# The following two work as expected

# what snapshot_meta expects us to pass
# review "barret" variant only
snapshot_review("barret/", path = test_dir)
# review "another" variant only
snapshot_review("another/", path = test_dir)

# also works because it checks all recursive dirs? 
# This makes us review all changed snapshots, both
# "barret" and "another"
snapshot_review(path = test_dir)

^{Created on 2026-02-20 with reprex v2.1.1}

Session info

sessioninfo::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value
#>  version  R version 4.5.2 Patched (2025-10-31 r88977)
#>  os       macOS Tahoe 26.3
#>  system   aarch64, darwin20
#>  ui       X11
#>  language en
#>  collate  en_US.UTF-8
#>  ctype    en_US.UTF-8
#>  tz       Europe/Berlin
#>  date     2026-02-20
#>  pandoc   3.6.3 @ /Applications/RStudio.app/Contents/Resources/app/quarto/bin/tools/aarch64/ (via rmarkdown)
#>  quarto   1.7.33 @ /usr/local/bin/quarto
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version date (UTC) lib source
#>  brio          1.1.5   2024-04-24 [1] CRAN (R 4.5.0)
#>  cli           3.6.5   2025-04-23 [1] CRAN (R 4.5.0)
#>  crayon        1.5.3   2024-06-20 [1] CRAN (R 4.5.0)
#>  desc          1.4.3   2023-12-10 [1] CRAN (R 4.5.0)
#>  diffobj       0.3.6   2025-04-21 [1] CRAN (R 4.5.0)
#>  diffviewer    0.1.2   2024-06-12 [1] CRAN (R 4.5.0)
#>  digest        0.6.39  2025-11-19 [1] CRAN (R 4.5.2)
#>  evaluate      1.0.5   2025-08-27 [1] CRAN (R 4.5.0)
#>  fastmap       1.2.0   2024-05-15 [1] CRAN (R 4.5.0)
#>  fs            1.6.6   2025-04-12 [1] CRAN (R 4.5.0)
#>  glue          1.8.0   2024-09-30 [1] CRAN (R 4.5.0)
#>  htmltools     0.5.9   2025-12-04 [1] CRAN (R 4.5.2)
#>  httpuv        1.6.16  2025-04-16 [1] CRAN (R 4.5.0)
#>  jsonlite      2.0.0   2025-03-27 [1] CRAN (R 4.5.0)
#>  knitr         1.51    2025-12-20 [1] CRAN (R 4.5.2)
#>  later         1.4.6   2026-02-13 [1] CRAN (R 4.5.2)
#>  lifecycle     1.0.5   2026-01-08 [1] CRAN (R 4.5.2)
#>  magrittr      2.0.4   2025-09-12 [1] CRAN (R 4.5.0)
#>  mime          0.13    2025-03-17 [1] CRAN (R 4.5.0)
#>  otel          0.2.0   2025-08-29 [1] CRAN (R 4.5.0)
#>  pillar        1.11.1  2025-09-17 [1] CRAN (R 4.5.0)
#>  pkgload       1.5.0   2026-02-03 [1] CRAN (R 4.5.2)
#>  promises      1.5.0   2025-11-01 [1] CRAN (R 4.5.0)
#>  R6            2.6.1   2025-02-15 [1] CRAN (R 4.5.0)
#>  Rcpp          1.1.1   2026-01-10 [1] CRAN (R 4.5.2)
#>  reprex        2.1.1   2024-07-06 [1] CRAN (R 4.5.0)
#>  rlang         1.1.7   2026-01-09 [1] CRAN (R 4.5.2)
#>  rmarkdown     2.30    2025-09-28 [1] CRAN (R 4.5.0)
#>  rprojroot     2.1.1   2025-08-26 [1] CRAN (R 4.5.0)
#>  rstudioapi    0.18.0  2026-01-16 [1] CRAN (R 4.5.2)
#>  sessioninfo   1.2.3   2025-02-05 [1] CRAN (R 4.5.0)
#>  shiny         1.12.1  2025-12-09 [1] CRAN (R 4.5.2)
#>  testthat    * 3.3.2   2026-01-11 [1] CRAN (R 4.5.2)
#>  vctrs         0.7.1   2026-01-23 [1] CRAN (R 4.5.2)
#>  waldo         0.6.2   2025-07-11 [1] CRAN (R 4.5.0)
#>  withr         3.0.2   2024-10-28 [1] CRAN (R 4.5.0)
#>  xfun          0.56    2026-01-18 [1] CRAN (R 4.5.2)
#>  xtable        1.8-4   2019-04-21 [1] CRAN (R 4.5.0)
#>  yaml          2.3.12  2025-12-10 [1] CRAN (R 4.5.2)
#> 
#>  [1] /Users/S.Carl/Library/R/arm64/4.5/library
#>  [2] /Library/Frameworks/R.framework/Versions/4.5-arm64/Resources/library
#>  * ── Packages attached to the search path.
#> 
#> ──────────────────────────────────────────────────────────────────────────────

[cderv]

I ran into this in the tufte package and stepped through snapshot_meta() to find the root cause.

The problem is in snapshot_meta() (R/snapshot-manage.R ~L167-214). For variant snapshots like _snaps/my-variant/html.md, two things go wrong:

1. snap_test is set to the variant directory name (basename(dirname(cur)) → "my-variant"), not the test file name ("html")
2. snap_name becomes the variant-prefixed path: "my-variant/html.md"

So when the filter runs at L210:

out[out$name %in% files | out$test %in% dirs, , drop = FALSE]

with files = c("html", "html.md") and dirs = character(0), neither condition matches:

• "my-variant/html.md" %in% c("html", "html.md") → FALSE
• "my-variant" %in% character(0) → FALSE

Minimal standalone reprex confirming the issue is in snapshot_meta itself:

tmp <- tempfile("snapshotbug")
dir.create(file.path(tmp, "tests", "testthat", "_snaps", "my-variant"), recursive = TRUE)
writeLines("old", file.path(tmp, "tests", "testthat", "_snaps", "my-variant", "html.md"))
writeLines("new", file.path(tmp, "tests", "testthat", "_snaps", "my-variant", "html.new.md"))

path <- file.path(tmp, "tests", "testthat")

# No filter: found
testthat:::snapshot_meta(files = NULL, path = path)
#>         test               name  ...
#> 1 my-variant my-variant/html.md  ...

# Filter by test name: 0 rows
testthat:::snapshot_meta(files = "html", path = path)
#> [1] test name cur  new
#> <0 rows>

unlink(tmp, recursive = TRUE)