A test that fails once in a while on good code has a cause you can name. Six common ones, the clue each leaves in a failing run, and the fix for each.
A flaky test is one whose verdict flips although the code stayed put. Nothing changed between the green run and the red one, so the difference must come from something the test depends on without saying so: the speed of the machine, the calendar, the sequence of other tests, a random number, a server somewhere else. That is good news, because the list of hidden inputs is short. This guide goes through six causes that cover most cases, shows what each looks like when it fails, and gives a way to confirm it before you change anything. The aim is to replace "re-run it until it is green" with a named cause and a fix.
Read the full report on AISkills402: https://aiskills402.com/blog/flaky-test-causes?utm_source=devto&utm_medium=social
