The first sin that code is an unreadable code. Imagine variable names of functions and classes that mean nothing to you tons of ifs loops and a dense network of dependencies that start to give you a headache. Often even a comment in the code does not improve the situation. Besides commenting on unreadable code is also far from the idea of empathetic code. Programming practices such as SOLID DRY YAGNI and KISS did not come out of nowhere. Empathy is behind many good programming practices.
An unempathetic code is also one with the above mentioned faces. By mine I mean errors and traps in the code that were left intentionally. Such a trap may be for example an error left intentionally in the code. It could also Phone Number List be an unstable test or a test with an incorrect assertion.
An even worse case is a piece of code intentionally omitted from testing. I am far from adhering to the idea of % code coverage. However by leaving an important fragment of the code without verification in the form of a test we add another problem to our codebase. After all it may also be TODO fix later or TODO do it better left in the code only to be removed after a few years. I also encourage you to fight against the someone will fix it attitude.