A colleague reached out to me asking to generate a figure of gene neighborhood plots. I used a package for this but it took a considerable amount of time to work out all of the kinks. That colleague ended up using it (possibly 2 of the figures I generated) as main text figures.
Does this warrant authorship? I did not create a package for this and used a preexisting one but I would be willing to open source my code to reproduce the figures exactly.
I'd say it's unrelated to bioinformatics. Ask: https://academia.stackexchange.com
That desition is up to the main author, but I would say no, this is similar to a Graphic Designer working to make pretty images for the cover. At much, you can be at the "acknowledgment" section or ask for a payment for your time effort.