Introduction
ERT: Emacs Lisp Regression Testing
Assertions with `should`
Running a test case
Debug a test
Commercial break: Hyperbole
Instrument function on the fly
Mocking
cl-letf
Hooks
Side effects and initial buffer state
with-temp-buffer
make-temp-file
buffer-string
buffer-name
major-mode
unwind-protect
Input, with-simulated-input
Running all tests
Batch mode
Skipping tests
Conclusion