[HarHarVeryFunny]

IMO diffing might have made sense to do here, but that's not what they chose to do.

What's apparently happening is that React tells Ink to update (re-render) the UI "scene graph", and Ink then generates a new full-screen image of how the terminal should look, then passes this screen image to another library, log-update, to draw to the terminal. log-update draws these screen images by a flicker-inducing clear-then-redraw, which it has now fixed by using escape codes to have the terminal buffer and combine these clear-then-redraw commands, thereby hiding the clear.

An alternative solution, rather than using the flicker-inducing clear-then-redraw in the first place, would have been just to do terminal screen image diffs and draw the changes (which is something I did back in the day for fun, sending full-screen ASCII digital clock diffs over a slow 9600baud serial link to a real terminal).

[skydhash]

Any diff would require to have a Before and an After. Whatever was done for the After can be done to directly render the changes. No need for the additional compute of a diff.

[HarHarVeryFunny]

Sure, you could just draw the full new screen image (albeit a bit inefficient if only one character changed), and no need for the flicker-inducing clear before draw either.

I'm not sure what the history of log-output has been or why it does the clear-before-draw. Another simple alternative to pre-clear would have been just to clear to end of line (ESC[0K) after each partial line drawn.