is_leaf_type() returns True when the type is List of String

[obi1kenobi]

In [1]: from graphql import GraphQLString, GraphQLList

In [2]: from graphql.type.definition import is_leaf_type

In [3]: is_leaf_type(GraphQLList(GraphQLString))
Out[3]: True

See the current master implementation here: is_leaf_type() calls get_named_type(), which unwinds both lists and non-nulls to get at the inner type. The list unwinding is incorrect in this instance, as a list of strings is clearly a non-leaf type.

This is all using graphql-core version 1.0.1, the newest available on PyPI.

[syrusakbary]

Good catch. This was fixed in GraphQL-js in this commit: graphql/graphql-js@12b2137

A PR reflecting those changes will be always welcome! :)

[obi1kenobi]

@syrusakbary thanks for finding the JS version fix. I made a quick PR with the change you proposed.

On a validation-related note, do you think #97 might be something that's fixed in the upstream JS project, or could it be a new bug? I wasn't able to find it in the list of issues in that project, but perhaps you are more familiar with it and are better equipped to find the answer.