test_package: Run all tests in an installed package.
Description
Test are run in an environment that inherits from the package's namespace
environment, so that tests can access non-exported functions and variables.
Tests should be placed in tests/testthat. Use test_check with
R CMD check and test_pacakge interactively at the console.
If not NULL, only tests with file names matching this
regular expression will be executed. Matching will take on the file
name after it has been stripped of "test-" and ".r".
reporter
reporter to use
...
Additional arguments passed to grepl to control filtering.