Add db to output meta object for diamond/blastp

[erikrikarddaniel]

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Sorry for this, @vagkaratzas , but I need to keep track of the combination of fasta file and database so I need the output meta object to contain the id of the database's meta.

[vagkaratzas]

I feel it's becoming too much case-specific. I would keep it as is, and then do this little change in the local copy of the module, and keep track of the changes with "nf-core modules patch". More opinions are welcome for discussion.

[erikrikarddaniel]

The module is perfect for the case when you have one or more fasta files you want to align to one or more databases. You'll have an m x n matrix with results. For the next step to be able to keep track of which entries in an output channel is which combination of fasta file and database, you need to have the ids of both in the output meta. I can't see who it could possibly hurt to have that extra entry in the meta except if someone is using db for some other purpose.

[vagkaratzas]

Ok, I can listen to reason :P
Can you make an nf-test with such a case? 2 fastas and 2 dbs?

[erikrikarddaniel]

Ok, I can listen to reason :P

I know! :-)

Can you make an nf-test with such a case? 2 fastas and 2 dbs?

Yes, in a moment.

[erikrikarddaniel]

It turned out that I don't know how to call a module in nf-tests with actual channels, i.e. not just the single call one does in a process { } block. At the moment I'm a bit stressed about getting a new release of metatdenovo out, so I'll wait with adding the test until things have quieten down a bit so I have a chance to look at that.

However, I realized I had forgotten that it's important that prefix contains both the meta.id and the meta2.id/meta.db so I pushed a commit for that.