I was looking at zutty, mentioned in this thread - and the website says this:
> We have an automated regression testing setup to run VTTEST in Zutty and verify that the output is a pixel-perfect match of the pre-approved video output. You can thus expect the terminal output to be correct – be it driven by tmux, emacs (with org-mode, helm, magit, etc.) or whatever else.
> We have an automated regression testing setup to run VTTEST in Zutty and verify that the output is a pixel-perfect match of the pre-approved video output. You can thus expect the terminal output to be correct – be it driven by tmux, emacs (with org-mode, helm, magit, etc.) or whatever else.
Which sounds like it might be useful for you? https://github.com/tomszilagyi/zutty