## Summary:
I've felt for a while that types.go is way too confusing, and as I
started to implement some of the more complex cases of generating
interface-types, the cracks were really starting to show. Luckily, I
also finally realized how to fix it: we need to separate the process of
traversing the GraphQL operation and schema to decide what types to
generate from the process of actually generating those types. This
requires an extra set of intermediate data structures, but I think it
makes things quite a lot easier to understand -- and, importantly, it
means that the code-generation doesn't need to go in the order we
traverse the query/schema.
So in this commit, I did that huge refactor. It's probably best to just
review types.go and traverse.go as if they were new; the old code was
quite hard to understand and the new code will hopefully make a lot more
sense. (And to that end, review comments about what could be organized
better or needs more documentation are very much in order, even for code
that is mostly unchanged.)
This does introduce one bug, sort of, which is that rather than
generating broken code for list-of-interface fields, we generate no code
at all. (A TODO in unmarshal.go describes why.) I'll fix this when I
add support for those fields. (It's all behind the AllowBrokenFeatures
flag, anyway.) Otherwise, the only changes to generated code are that a
few methods are ordered differently, because we now generate the
implements-interface methods with the interface, rather than the
implementations, as it's much simpler that way. (In GraphQL, unlike Go,
we know the list of all possible implementations of each interface, so
this is possible.)
## Test plan:
golangci-lint run ./... && go test ./...
Author: benjaminjkraft
Reviewers: dnerdy, benjaminjkraft, aberkan, csilvers, MiguelCastillo
Required Reviewers:
Approved by: dnerdy
Checks: ✅ Lint, ✅ Test (1.17), ✅ Test (1.16), ✅ Test (1.15), ✅ Test (1.14), ✅ Test (1.13), ✅ Test (1.17), ✅ Test (1.16), ✅ Test (1.15), ✅ Test (1.14), ✅ Test (1.13), ✅ Lint
Pull request URL: https://github.com/Khan/genqlient/pull/51
Ben Kraft
8815d0991c