Combine @is and @provides

[smyrick]

These two directives are functionally doing the same thing we just limit them to different use cases with the directive locations.

They both tell the query planner that if you go through this path some of the data you will get back can be sourced either from an argument or it will be provided by the subgraph

I am open for discussion of not merging them. But at second glance they do seem very similar. It also helps with the short and unclear name of @is

[michaelstaib]

I think this looks great and would reduce cognitive complexity.

[dariuszkuc]

I don't think those two directives should be merged

• @provides is a query planner optimization, it means that some fields through some specific paths can be resolved locally so we don't have to jump to other subgraphs to get this data
• @is is a composition directive to mark two fields as equivalent (so they could be merged as one into the supergraph or args can be mapped to fields)

[michaelstaib]

@dariuszkuc we discussed it in the wg last week and came to the same conclusion. I am closing this PR