Selects and sanitizes the list of **wrapper** test files to execute during coverage, supporting both the standard `tests/` layout and the `testit` layout (`tests/testit/`). When `pkg_name` is `"data.table"`, the function adds package-aware behavior: it falls back to `tests/main.R` if the mapping yields no existing files and optionally prioritizes `froll.R` so rolling function tests run early.
compute_test_files_clean_dt(
pkg_name,
pkg_source_path,
clean_mapping,
test_pkg_data,
skip_tests = NULL
)`character()` - **normalized**, de-duplicated vector of wrapper file paths that **exist** on disk. May be zero length if no candidates exist and no fallback is available.
`character(1)`. Package name.
`character(1)`. Absolute or relative path to the package source root.
A data frame or list containing at least a `test_file` column/element with **relative** wrapper paths to run. Paths are resolved against `tests/` or `tests/testit/` depending on `test_pkg_data$has_testit`.
`list`. Must include logical flag `has_testit` indicating whether the package uses a `tests/testit/` layout.
`NULL` or `character()`. Relative wrapper paths to exclude (matched within the chosen base directory).
This helper **only resolves file paths**; it does **not** modify the evaluation environment, copy/mirror test assets, or toggle data.table's test harness mode. Any package-specific preparation (e.g., mirroring `inst/tests/` to `tests/` or exposing `test.data.table()` in dev mode) must be handled elsewhere (see `prepare_tests_for_package()`).