Is there a pattern for testing mutations directly?

[jjb]

Is there a pattern for testing mutations directly, without going through the HTTP or controller layer? This blog post proposes one:

https://www.codementor.io/karanjaeddy/build-a-to-do-list-api-with-graphql-api-rails-5-part-1-irjt1e7jm#mutations

But I haven't been able to get it to work in my app for an endpoint of this form

  DoThing = GraphQL::Relay::Mutation.define do
    name "doThing"
    resolve →(obj, inputs, ctx) {

I want to invoke resolve on something but I can't figure out how to get to it in UserMutations::CompleteCheckout. There's a @resolve_proc instance variable but I would have to use metaprogramming to access it.

Let me know any ideas and I'll try to contribute to the docs with what I come up with!

[rmosolgo]

without going through the HTTP or controller layer?

You can call MySchema.execute(...) directly, with a GraphQL query string, but that's the only other option that I know of.

I recommend writing an "integration test" like that ☝️ , but then extracting all the mutation's logic into plain ol' Ruby code, and unit testing that separately.

For example, if you have a complicated AddUserToTeam mutation, add

# app/models/user/add_to_team.rb
class User::AddToTeam 
  def initialize(graphql_inputs) 
    # ...
  end 

  def perform 
    # ... do the stuff 
  end 
end 

Then test that class on its own. (Call it a "Service object" if you like :P)

Then the mutation's resolve is "just":

User::AddToTeam.new(args).perform 

[jjb]

Thanks! Here's what I came up with: https://github.com/rmosolgo/graphql-ruby/wiki/Writing-tests-for-mutations