@AlessandroMinoccheri sure. Let's say there are two UndefinedMethod violations saying The method SomeClass::expects does not exist in this code:

private SomeClass $mock;
// ...
$this->mock->expects($this->once())
// ...
$this->mock->expects($this->once())

The baseline file looks like this:

<file src="Test.php">
    <UndefinedMethod>
       <code>expects</code>
       <code>expects</code>
    </UndefinedMethod>
</file>

It's also not ideal, especially since the code snippet is sometimes really weird/random, like in this example: <code>ry\Adapter\O</code> But even though it's sometimes bullshit, it works fine for us ✌️

I'm really happy to see this PR. I've the same struggle, everytime we change imports or class attributes the line numbers are chaning. Having an option to ignore them would be a good compromise for us too.

Another option could be what psalm is kind doing. They store a code snippet instead of the line number.