Watches R files in the app directory and tests/testthat directory for changes.
When code files in app change, all tests are rerun. When test files change,
only the changed test file is rerun.
filter passed to testthat::test_dir(). If not NULL, only tests with file names matching this regular expression will be executed.
Matching is performed on the file name after it's stripped of "test-" and ".R".
Does not affect the case when a test file is changed. In this case, this test file is rerun.
hash
Logical. Whether to use file hashing to detect changes. Default is TRUE.
If FALSE, file modification times are used instead.