The point isn't that test don't provide confidence. It's that they can only show the presence of bug, by virtue of failing when a given bug is present. But importantly, they only do that for the bugs that the implementing developer thought of. They don't show it fall for all possible bugs (unless the implementing develop thought of all of them, which isn't often the case).
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
The point isn't that test don't provide confidence. It's that they can only show the presence of bug, by virtue of failing when a given bug is present. But importantly, they only do that for the bugs that the implementing developer thought of. They don't show it fall for all possible bugs (unless the implementing develop thought of all of them, which isn't often the case).