TESTING.md

How to write tests for gqlgen

Testing generated code is a little tricky, heres how its currently set up.

Testing responses from a server

There is a server in codegen/testserver that is generated as part of go generate ./..., and tests written against it.

There are also a bunch of tests in against the examples, feel free to take examples from there.

Testing the errors generated by the binary

These tests are really slow, because they need to run the whole codegen step. Use them very sparingly. If you can, find a way to unit test it instead.

Take a look at codegen/testserver/input_test.go for an example.

Testing introspection

Introspection is tested by diffing the output of graphql get-schema against an expected output.

Setting up the integration environment is a little tricky:

cd integration
go generate ./...
go run ./server/cmd/integration/server.go

in another terminal

cd integration
npm install
./node_modules/.bin/graphql-codegen

will write the schema to integration/schema-fetched.graphql, compare that with schema-expected.graphql

CI will run this and fail the build if the two files don't match.