Add GraphQL::Execution::Errors module

[AleksandrSeleznev]

Summary

@ArthurZaharov suggested to implement these GraphQL::Execution::Errors module in order to be able to handle errors.

How it works

We can handle errors with rescue_from method. For example, for ActiveRecord::RecordNotFound:

rescue_from(ActiveRecord::RecordNotFound) do |_err, _obj, _args, _ctx, field|
    raise GraphQL::ExecutionError.new("#{field.type.unwrap.graphql_name} not found",
                                      extensions: { message: "Not Found", status: 404, code: :not_found })
  end

Test plan

N/A

Review notes

While reviewing pull-request (especially when it's your pull-request),
please make sure that:

• you understand what problem is solved by PR and how is it solved
• new tests are in place, no redundant tests
• DB schema changes reflect new migrations
• newly introduced DB fields have indexes and constraints
• there are no missed files (migrations, view templates)
• required ENV variables added and described in .env.example and added to Heroku
• associated Heroku review app works correctly with introduced changes

Deploy notes

N/A

References

N/A

[EvgeniyEsaulkov]

Can you please add a test for some graphql query or mutation that illustrates how it work?

[AleksandrSeleznev]

Can you please add a test for some graphql query or mutation that illustrates how it work?

@EvgeniyEsaulkov is it necessary to implement separated spec for this?
I haven't found any query or mutation with find method for some Model, only find_by.

[EvgeniyEsaulkov]

I haven't found any query or mutation with find method for some Model, only find_by

That's why I asked :-)
What are the benefits to add code that probably will used never? And in case we will use .find in some query or mutation in the future, would it better to specify error explicitely in application schema?

[EvgeniyEsaulkov]

@AleksandrSeleznev I discussed addding of errors to Application Schema with FE developers - they are not happy with that. So I think we can use your solution for now - every project we started on the base of rails-base-graphql-api uses .find method.