meta.json contains null fields

[lowyck]

When creating an exercise from an input file with missing metadata fields, the generated meta.json contains fields with value null. It is avoidable by not generating the meta file at all. Currently, an warning is printed. I think it is better to leave it as is, because building will fail anyway without a meta.json, but not with a null value inside a field that is not strictly mandatory (e.g authors).

[yurug]

Not sure to understand the part "to leave it as is". You mean that the behavior of learn-ocaml should not be changed?

[lowyck]

I meant keep the current behaviour of autogen, i.e printing a warning, and outputting a json file, even with null values in it.

[yurug]

I see and I agree.