A story of @vue/test-utils update in GitLab

During 2020 Ilya updated @vue/test-utils twice in GitLab and it took an enormous amount of time. To complete upgrades he has made over 10 pull requests to @vue/test-utils, discuss in Gitlab frontend RFC opportunity to fork it, develop a deep understanding of Vue reactivity and start a holy war for code quality both in GitLab and @vue/test-utils

In this talk Ilya will cover the following topics:

• what is the hidden complexity of testing such systems;
• what wrong decisions (in my opinion) were made by @vue/test-utils developers and how we could avoid them;
• how reactivity makes reliable systems complex;
• how to write reliable Vue.js tests.

This talk will be useful not only for Vue.js developers but also for everyone who trusts in unit-testing as a key to predictable management of any project.