The tests in the package P are run (in separate Macaulay 2 processes), and any errors are reported.
Description
For example, to run the tests for the LLLBases package (Lenstra-Lenstra-Lovasz bases) do the following.
installPackage "LLLBases"
check LLLBases
It is important for package authors to provide tests to insure that the package is functioning properly. One provides tests using TEST in the beginDocumentation section.