Macaulay2 package TestIdeals - a package for calculations of singularities in positive characteristic. TestIdeals is a package for basic computations of F-singularities. It is focused on computing test ideals and related objects. It does this via frobeniusRoot, which computes I[1/pe], as introduced by Blickle-Mustata-Smith (this is equivalent to the image of an ideal under the Cartier operator in a polynomial ring).