User blog comment:Kirkburn/VisualEditor - the past, present and future/@comment-452-20140624141654/@comment-452-20140630165252

"No bugs" is unlikely. There will always be edge cases that even the best testing may miss, but releasing with known bugs is abhorrent behaviour.

Testing and bug-fixing is vital part of of the software development life cycle.

Web development with an existing database gives you a vast amount of input data for tests. A script to load each page in the database though the Visual Editor and log changes would be trivial to implement, and is an obvious test to use if the goal of the Visual Editor is to make no changes to existing wiki-text.