A collection of Bad Code Smells in a Catalog form for Developers & Researchers. Code Smell is a typical bad code implementation, and learning these concepts immiedietly makes you a better developer!
  • @[email protected]English
    10•2 months ago

    The items don’t seem concise and always clear. But seems like a good, inspiring resource for things to consider.

    If it is expected that a method might fail, then it should fail, either by throwing an Exception or, if not - it should return a special case None/Null type object of the desired class (following the Null Object Pattern), not null itself.

    I’ve never heard of evading null with a Null object. Seems like a bad idea to me. Maybe it could work in some language, but generally I would say prefer result typing. Introducing a result type wrapping or extending the result value type is complexity I would be very evasive to introduce if the language doesn’t already support result wrapper/state types.

  • @[email protected]
    6•2 months ago

    This doesn’t seem overly useful.

    It’s a list taken out of a bunch of books with no regard for how something can be the best path in one language and a smell in another language.

    Look at this page for example: https://luzkan.github.io/smells/imperative-loops

    It suggests using functional loop methods (.map(), .reduce(), .filter()) instead of using imperative loops (for, for in, for each) but completely disregards the facts that imperative loops also have access to the break, continue, and return keywords to improve performance.

    For example: If I have an unsorted list of 1000 cars which includes a whole bunch of information per car (e.g. color, year manufactured, etc…), and I want to know if there were any cars were manufactured before the year 1980, I can run an imperative loop through the list and early return true if I find one, and only returning false if I haven’t found one by the end of the list.

    If the third car was made in 1977, then I have only iterated through 3 cars to find my answer.

    But if I were to try this with only functional loops, I would have to iterate through all 1000 cars before I had my answer.

    A website with blind rules like this is going to lead to worse code.

    • @CookieOfFortune
      11•2 months ago

      That’s a pretty bad example since most functional frameworks include an any or some function that returns early.

    • @[email protected]
      8•2 months ago

      …what? At least with Java Streams or Kotlin Sequences, they absolutely abort early with something like .filter().first().

      • @[email protected]English
        10•2 months ago

        Same in Python, Rust, Haskell and probably many others.

        But apparently JS does work that way, that is its filter always iterates over everything and returns a new array and not some iterator object.

      • @[email protected]
        5•2 months ago

        Ya, streams may seem tedious (why do I have to call stream and collect?), but it’s like that for performance (and probably backwards compatibility).

        If writing readable code is not peformant, then the language implementation needs to be fixed.

        • @[email protected]
          5•2 months ago

          Honestly, it is much more code to use loop with non-local control like break, continue etc. (variable initialization, append, variable mutation in loops…) than just calling a collect function (which I assume just means to_list). In the above example, in most programming language I know, you don’t even need to collect the result into a list.

          Not to mention, large loops with non-local control is a breeding ground for spegatti code. Because you no longer have a consistent exit point to the loop, thus making the semantics hard o reason about.

          In many languages, there are type class / trait / interfaces (whatever you want to call them) that allows lazy structures to share the same API as strict ones.

          • @[email protected]
            3•2 months ago

            Yeah, in Java calling first() on a stream is the same as an early return in a for-loop, where for each element all of the previous stream operations are applied first.

            So the stream operation

            cars.stream()
    .filter(c -> c.year() < 1977)
    .first()

            is equivalent to doing the following imperatively

            for (var car : cars) {
    if (car.year() < 1977) return car;
}

            Not to mention Kotlin actually supports non-local returns in lambdas under specific circumstances, which allows for even more circumstances to be expressed with functional chaining.

            • @[email protected]English
              4•2 months ago

              These are not quite equivalent. In terms of short-circuiting yeah they both short-circuit when they get the value. But the latter is returning from the current function and the former is not. If you add a return to that first example then they are equivalent. But then cannot be used in line. Which is a nice advantage to the former - it can be used inline with less faff as you can just assign the return to a value. The latter needs you to declare a variable, assign it and break from the loop in the if.

              Personally I quite like how the former requires less modification to work in different contexts and find it nicer to read. Though not all logic is easier to read with a stream, sometimes a good old for loop makes the code more readable. Use which ever helps you best at each point. Never blindly apply some pattern to every situation.

    • JackbyDevEnglish
      2•2 months ago

      Also, Effective Java specifically says to use streams judiciously and prefer traditional for loops in general.