Feature request: code coverage

[mm-gmbd]

Not sure if this could/would be included in nutkin or in a separate package that is used in concert with nutkin, but just curious if there has been any thought given to providing a code coverage metric.

Btw, looks like a great library!

[leoedin]

Hello,

To my knowledge we haven't looked into code coverage. It's not something we're planning on working on right now, but we'd definitely consider merging a PR if one was provided.

Just giving it some thought today -
You can make use of the special squirrel function setdebughook() to be called every time a line is executed when squirrel is run with the debug flag (-d). Your debughook is called every time squirrel executes a new line, so its fairly straightforward to build a table with every function and line called during the test.

As an example:

codeCoverage <- {};

// Experimental code coverage test
function debughook(event_type,sourcefile,line,funcname)
{
    local fname=funcname?funcname:"unknown";
    local srcfile=sourcefile?sourcefile:"unknown"
    switch (event_type) {
    case 'l': //called every line(that contains some code)
        if (!(srcfile in codeCoverage))
        {
            codeCoverage[srcfile] <- {};
        }

        if (!(fname in codeCoverage[srcfile]))
        {
            codeCoverage[srcfile][fname] <- {};
        }
        codeCoverage[srcfile][fname][line] <- true;

        break;
    case 'c': //called when a function has been called
        break;
    case 'r': //called when a function returns
        break;
    }
}

setdebughook(debughook);

You'd then need to find some way of parsing the code for every possible executable line, and compare the two. I'm not sure if that would be possible using squirrel hooks - you may need to do it within the C++ squirrel interpreter.

Thanks,

Leo