data-plumbing-for-corporations tends to be able to be done in a way that’s easily testable, but also most people get paid to bolt on new shit onto old shit and spending time on “done” code is discouraged so once they fall behind on writing tests while developing the new shit those tests will never be written.

and bad developers that won’t write tests no matter what actually do exist.

i’ve only read about rust, but is there a way to influence those automatic implementations?

equality for example could be that somethings literally point to the same thing in memory, or it could be that two structs have only values that are equal to each other

Strings are Objects, Doubles are Objects (that are than unboxed into primutives doubles)…

the “what” is interesting on interfaces or when you generate documentation with some tool like sphinx or javadoc.

the “why” is interesting when you are somewhere inside a class or function and do something in a “strange” way, to work around a quirk in the codebase or something like that, or when you employ optimizations that make the code harder to read or atleast less obvious why somethings are done.

good Tester.

If something stupid can be done, it will be done.

there is no “undefined” in java. this would either be a map containing the key value pair (“name”, null) or it would be mapped to an object of some class with an attribute “name” which can hold a null value. in any case {} wont equal {“name”:null}.