Heatmaps break with report "Show only matching samples"

[ewels]

Reported by @sergpolly in #1137 (comment)

working on this I realized another potential issue with applying toolbox to the heatmaps ...
screaming, when one chooses to hide in Show only matching sa mples-regime - see another demo:

SRR106 matches a bunch of samples but none of the xcats - column labels - which makes heatmap yield "blank" - should I open another issue to keep this in the record ?

So this specifically is a problem when using Show only matching samples in the report "Show / Hide" panel in combination with heatmaps that do not have sample names on both axes.

This is tricky to fix as we don't currently know which things in heatmaps are categories and which are sample names. I think that we might need to have a new plot config option to handle this (and a new lint test for it so that we can go through and implement this in all existing heatmaps).

[ewels]

Hi @sergpolly,

Thanks again for reporting this, good spot! I have now implemented a fix by adding two new config options that allow you to specify that a heatmap axis does not contain sample names (see c2abbd9).

I went through all of the heatmaps in core MultiQC modules and I think this issue only affected FastQC status and the new iVar module. I've added the options there and it seems to work well.

Let me know if you spot any others!

Phil