Singularize and capitalize polymorphic types

[dpdawson]

Singularizing polymorphic association types allows you to use plural or singular type values in your requests as allowed by JSON API.

Because ActiveRecord calls #constantize on the polymorphic association type when you use the hash to create a new model, you must capitalize the type to avoid a NameError.

[bf4]

@dpdawson Awesome! Would you mind adding a changelog entry at the top of the fixes section? Also, a test of an ActiveRecord object using this result would be fantastic, if you don't mind the extra effort.

[dpdawson]

As I looked into it more, I realized the error only gets thrown when you validate the relationship is present. The fix doesn't cause any of the other tests to fail, so I assume it's ok.

I added a test, but I'm sure it's not the best implementation because I don't use Minitest and the organization of the tests is a bit difficult to discern at first glance.

[bf4]

With a rebase and a brief look at the Transformer with @remear this should be ready to mege

[dpdawson]

I'd be happy to take a look if pointed in the right direction.

[remear]

@dpdawson Could you rebase this off master and take a look at adjusting KeyTransform to suit the needs of singularize.capitalize.

[bartiaco]

Any updates on this? Or has the problem been solved in a different way? I'm currently running into this issue.

[bartiaco]

One note: I don't think the current implementation will work for multi-word classes, given that the standard wordbreak in jsonapi is a '-'

"blog-posts".singularize.capitalize => "Blog-post"

[brunowego]

I get this situation here, by now, I solve with hardcoded fix on controller. I made a SO because I had not seen this. Please consider merge it.

[bf4]

@brunowego @bartiaco I'm reading the comments above and looks like the PR didn't get finished by anyone. Unless @dpdawson wants to pick it up again, it'll need to be reworked against master, and also related #1928 cc @NullVoxPopuli