Overall cyclomatic complexity is a useful metric, but it does have one shortcoming when used with modern languages: it was invented before polymorphism really became a thing.
That means that it really only counts explicit branching. So, for example, in an OO language like C#, calling a virtual method doesn’t increment cyclomatic complexity even though the method invocation could go down many code paths. Potentially thousands if you’re dealing with a common interface like IEnumerable. If you’re working on a library then the number of potential code paths in this kind of situation is unbounded.
As an aside, it’s interesting to think how it might apply to a language like Smalltalk that doesn’t even have if or switch statements.
OO isn’t the only monkey wrench, either. Higher-order functions also introduce forms of branching that cyclomatic complexity doesn’t measure.
Again that doesn’t make it a useless metric. Just don’t think that a cyclomatic complexity limit in your codebase is some sort of maintainability panacea. Some of the least comprehensible functions I’ve deciphered had quite low cyclomatic complexities.
> Some of the least comprehensible functions I’ve deciphered had quite low cyclomatic complexities.
In agreement with your post, this research that measures cognitive load via EEG and time spent shows that the metrics we use for complexity and readability are only partial matches to what is going on:
<a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9942489/" rel="nofollow">https://pmc.ncbi.nlm.nih.gov/articles/PMC9942489/
bunderbunder · · focus · HN ↗
That means that it really only counts explicit branching. So, for example, in an OO language like C#, calling a virtual method doesn’t increment cyclomatic complexity even though the method invocation could go down many code paths. Potentially thousands if you’re dealing with a common interface like IEnumerable. If you’re working on a library then the number of potential code paths in this kind of situation is unbounded.
As an aside, it’s interesting to think how it might apply to a language like Smalltalk that doesn’t even have if or switch statements.
OO isn’t the only monkey wrench, either. Higher-order functions also introduce forms of branching that cyclomatic complexity doesn’t measure.
Again that doesn’t make it a useless metric. Just don’t think that a cyclomatic complexity limit in your codebase is some sort of maintainability panacea. Some of the least comprehensible functions I’ve deciphered had quite low cyclomatic complexities.
RaftPeople · · focus · HN ↗
In agreement with your post, this research that measures cognitive load via EEG and time spent shows that the metrics we use for complexity and readability are only partial matches to what is going on: <a href="https://pmc.ncbi.nlm.nih.gov/articles/PMC9942489/" rel="nofollow">https://pmc.ncbi.nlm.nih.gov/articles/PMC9942489/