Run middleware inside of GraphQL execution

[spawnia]

Is your feature request related to a problem? Please describe.

When querying a field that does use Laravel Middleware via @middleware, and an Exception is thrown in the Middleware, the Request fails before we are in the GraphQL execution context. The resulting Response is not a proper GraphQL response, it does not conform to the specification.

The problem with this becomes even more apparent when you consider that one might query multiple fields in a single request. A failure in one field would cause the whole query to abort. However, the correct behaviour would be to return an error for one field and resolve the other field as usual.

Describe the solution you'd like

We might use the Context, which is the third resolver argument, to call the Middleware on a per-field basis, while we are already during GraphQL execution.

This would also solve another issue: We are currently forced to load all fields of the root Query and Mutation types to evaluate if they have middleware. Deferring the Middleware execution would allow us to load those fields lazily, just like any other field.

Possible issues

• We have to ensure that we always have the request available as part of the Context object
• This would change the behaviour of Middleware execution in a possibly breaking way

TODOs

• Get inner middlewares from directives working
• Consider Disable global middleware for a subset of fields #385
• Global middleware from the config vs. directive config
• Write comprehensive tests
• Document the changes

[yaquawa]

Agree! I'm facing the same problem.
It's good to have the lazy loading too.❤️

[spawnia]

@chrissm79 @yaquawa @olivernybroe @enzonotario @robsontenorio

Just put up a WIP PR #395 that will resolve this, looking for feedback on what i need to consider for the tests and to avoid breaking changes.