This file provides functions to support ert, the Emacs Regression Test framework. It includes: - a set of predicates for comparing strings, buffers and file contents. - explainer functions for all predicates giving useful output - macros for creating many temporary buffers at once, and for restoring the buffer list. - methods for testing indentation, by comparison or "round-tripping". - methods for testing fontification. Assess aims to be a stateless as possible, leaving Emacs unchanged whether the tests succeed or fail, with respect to buffers, open files and so on; this helps to keep tests independent from each other. Violations of this will be considered a bug. Assess aims also to be as noiseless as possible, reducing and suppressing extraneous messages where possible, to leave a clean ert output in batch mode.