Snapshot refactoring

[hadley]

• Generalise test_file_reporter() so we no longer need test_files_reporter_parallel()
• Remove code needed for old R
• Drop deprecated argument

local_snapshotter() is only used in devtools.

In preparation for #2066

[gaborcsardi]

All good, but see one comment below.

[claude]

Claude finished @hadley's task —— View job

---

Code Review Progress

• Read changed files and analyze refactoring
• Check for potential bugs or issues
• Evaluate reviewer suggestion about match.arg()
• Provide feedback

Review

The refactoring looks clean and appropriate. Two observations:

1. Missing match.arg() validation: Reviewer gaborcsardi correctly noted that test_files_reporter() should validate the mode parameter. Currently at line 323 in R/test-files.R:325, mode <- arg_match(mode) is called, but this should be added right after the function signature for proper parameter validation.

2. Argument name consistency: The refactoring changes .env to frame parameter in test_files_reporter() and removes the explicit snap_dir parameter from local_snapshotter() call, which is fine since it defaults to "_snaps".

The generalization to eliminate test_files_reporter_parallel() is well-executed - the conditional logic for snapshot reporter selection is clean and the function signature unification makes sense.

LGTM with the suggested match.arg() addition.