API docs : `distribution` behaviour not consistent for (?) integer and date variables

[bobular]

We've started using the distribution endpoint as a supplementary data source for the histogram visualization. It gets the full range of the data for the variable, so we can figure out truncation warnings correctly when the user has "zoomed in" to a custom x-axis range viewport. See https://github.com/VEuPathDB/web-monorepo/pull/376 for details.

Anyway, the API docs say that the binSpec is optional but we've found some cases where if we omit the binSpec prop in the POST body, errors occur

GEMS1

• Age -> gives a 500 (NullPointerException at org.gusdb.fgputil.distribution.IntegerBinDistribution.getTypedObject(IntegerBinDistribution.java:34)
• Birth date -> 400 error - Variable EFO_0004950 of type DATE: displayRangeMin must be a date string value, not null

It seems that regular floating point continuous vars work fine without a binSpec in the request.

Solutions could be

• do nothing (we added the binSpec to the request for the new use case)
• fix the docs
• fix the code (and then we can remove a few lines of code in the client)

[ryanrdoherty]

If I remember correctly, the subsetting code is supposed to populate a binSpec from the data range values in the variable metadata if the property is omitted before the request, then hand the generated binSpec to the distribution generation library (FgpUtil). I don't really like either of those messages above (would rather see IllegalArgumentException vs NPE in the first bullet.

[bobular]

I've seen merged code which replaces the NullPointerException with IllegalArgumentException. Not sure about documentation status.

[bobular]

I'm thinking we should revisit this with further testing when https://github.com/VEuPathDB/EdaDataService/pull/309 is merged.