Cyclomatic Complexity in Visual Studio

Question

I do some tests with Visual Studio Code Metrics. As I can calculate the Cyclomatic Complexity, each if, while, for - operators increase the complexity with 1. I have the next simple method:

static bool ContainsNegative(int a, int b, int c, int d)
    {
        if (a < 0 || b < 0 || c < 0 || d < 0) return false;
        return true;
    }

But for it, the Cyclomatic Complexity is 5, instead of 2 (1 for the method + 1 for the if). My question is - this is because the Code Metrics calculate each condition in if operator as a different if? I.e. my method is equivalent to:

static bool ContainsNegative(int a, int b, int c, int d)
    {
        if (a < 0) return false;
        if (b < 0) return false;
        if (c < 0) return false;
        if (d < 0) return false;
        return true;
    }

Here is a screen with results:

Also, is there a list with all rules described in details?

Thank you!

It is a very simplistic measurement, it counts the branches in the code. Since you used || instead of | (the short-circuiting operator) you never have less then 4. Using | in fact can generate much faster code in this case, but tends to generate too many wtf exclaims from the reader. Which is pretty much the key to using the tool appropriately, you only look for the red flags and have a look if the code truly has a readability problem. It doesn't, move on. — Hans Passant, Oct 03 '18 at 13:51

score 9 · Answer 1 · answered Oct 03 '18 at 13:36

9

Cyclomatic Complexity measures the number of paths through a function. As you suggest that means that a 1 is added for each control flow statement plus 1 for each logical NOT, AND and OR in each condition.

What the value of 5 is telling you is that you will need 5 unit tests in order to get 100% code coverage of your function.

answered Oct 03 '18 at 13:36

Philip Smith

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3

The OP's confusion is understandable as Cyclomatic Complexity is defined in different ways. Also there are several types of code coverage; CC provides an upper bound on the number of tests you'll need to achieve basis path coverage (it's an upper bound as some paths may not be possible to traverse). – ComDubh Mar 04 '19 at 15:24

Cyclomatic Complexity in Visual Studio

1 Answers1