New variant `expect_snapshot_file()` files are being removed

[schloerke]

Similar to #1462, but with variant = "something".

Example output with variant = "mac-4.0":

ℹ Loading shinytest2
✔ | F W S  OK | Context
✔ |         5 | apps-web-example [2.4s]
✔ |         4 | shiny-driver-click [2.6s]
✔ |         5 | shiny-driver-init-args [3.2s]
✖ | 1      11 | shiny-driver-set-inputs [3.9s]
──────────────────────────────────────────────
Failure (test-shiny-driver-set-inputs.R:44:3): set kitchen sink of inputs
Snapshot of `snapshot_info$screenshot_path` to 'shiny-driver-set-inputs/input-widgets-004.png' has changed
Run `testthat::snapshot_review('shiny-driver-set-inputs')` to review changes
Backtrace:
 1. app$expectSnapshot(screenshot = TRUE) test-shiny-driver-set-inputs.R:44:2
 2. shinytest2::sd2_expectSnapshot(...) /Users/barret/Documents/git/rstudio/shinytest/shinytest2.nosync/R/shiny-driver.R:570:6
 3. testthat::expect_snapshot_file(...) /Users/barret/Documents/git/rstudio/shinytest/shinytest2.nosync/R/testthat.R:41:4
──────────────────────────────────────────────
✔ |         3 | z-external-packages [3.2s]

══ Results ═══════════════════════════════════
Duration: 15.4 s

[ FAIL 1 | WARN 0 | SKIP 0 | PASS 28 ]
Deleting unused snapshots:
* mac-4.0/shiny-driver-set-inputs/input-widgets-004.new.png
Error: Test failures

# No _new_ file being kept
❯❯ system("tree tests/testthat/_snaps/mac-4.0/shiny-driver-set-inputs/")
tests/testthat/_snaps/mac-4.0/shiny-driver-set-inputs/
├── input-widgets-001.json
├── input-widgets-001.png
├── input-widgets-002.json
├── input-widgets-002.png
├── input-widgets-003.json
├── input-widgets-003.png
├── input-widgets-004.json
└── input-widgets-004.png

0 directories, 8 files

[hadley]

Reprex:

library(testthat)
dir <- withr::local_tempdir()
snapper <- testthat:::local_snapshotter(dir)

snapper$start_file("test", "test")
test_that("test", {
  local_edition(3)
  path <- withr::local_tempfile()
  writeLines("a", path)
  expect_snapshot_file(path, "test.txt", variant = "foo")
})
#> ── Warning (<text>:10:3): test ─────────────────────────────────────────────────
#> Adding new file snapshot: '/tmp/RtmpVVEEvT/file1472b72601201/foo/test/test.txt'
snapper$end_file()
snapper$end_reporter()
dir(file.path(dir, "foo", "test"))
#> [1] "test.txt"

snapper$start_reporter()
#> NULL
snapper$start_file("test", "test")
test_that("test", {
  local_edition(3)
  path <- withr::local_tempfile()
  writeLines("b", path)
  expect_snapshot_file(path, "test.txt", variant = "foo")
})
#> ── Failure (<text>:22:3): test ─────────────────────────────────────────────────
#> Snapshot of `path` to 'test/test.txt' has changed
#> Run `testthat::snapshot_review('test')` to review changes
snapper$end_file()
snapper$end_reporter()
#> Deleting unused snapshots:
#> * foo/test/test.new.txt
dir(file.path(dir, "foo", "test"))
#> [1] "test.txt"

^{Created on 2022-01-03 by the reprex package (v2.0.1)}

[hadley]

Simpler reprex with using some helpers (except they somehow break reprex?)

library(testthat)
dir <- withr::local_tempdir()
snapper <- testthat:::local_snapshotter(dir)

snapshot_this <- function(code, file = "file.R", test = "test") {
  snapper$start_reporter()
  withr::defer(snapper$end_reporter())
  
  snapper$start_file(file, test)
  withr::defer(snapper$end_file())
  
  local_edition(3)
  code

  invisible()
}

local_tempfile1 <- function(lines, env = parent.frame()) {
  path <- withr::local_tempfile(.local_envir = env)
  writeLines(lines, path)
  path
}

snapshot_this({
  path <- local_tempfile1("a")
  expect_snapshot_file(path, "test.txt", variant = "foo")
})
dir(file.path(dir, "foo", "test"))

snapshot_this({
  path <- local_tempfile1("b")
  expect_snapshot_file(path, "test.txt", variant = "foo")
})
dir(file.path(dir, "foo", "test"))

[schloerke]

✅ Thank you!