at least some multi-value parameters are using the wrong style (based on responses from the servers) and, thus, are semi-broken

[ronreynolds]

if fixing errors in the openapi spec is an idea then i guess this is an idea (since there didn't seem to be a "file a bug" option). originally sent this to Etsy Dev Support; they 302'ed me here.

regarding openapi spec there's an issue where parameters like
#/paths/v3/application/listings/{listing_id}/get/parameters/1("includes") don't specify the style (i.e., they use the default style per the openapi spec).

according to the openapi spec 3.0.2 the default style for in:query parameters is style:form. the result of this is if you specify all includes you get only Videos back because the server is using the last key=value pair on the query-string and not the combination of all includes=... query parameters. based on my own testing these values are expected to be key=v1,v2,v3(style:simple) rather than key=v1&key=v2&key=v3 (style:form).

i've verified this with my own copy of the spec.
this should be an issue for all users regardless of code-gen being used (i use the openapi-codegen; language:java, library:native).