0.17.0 breaks as_json/to_json on graphql response

[navied]

It seems like 0.17.0 introduces a SystemStackError when to_json or as_json is done on the graphql response see below for stacktrace:

res.data.to_json
Traceback (most recent call last):
       16: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `as_json'
       15: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `each'
       14: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:175:in `block in as_json'
       13: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:58:in `as_json'
       12: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `as_json'
       11: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `each'
       10: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:175:in `block in as_json'
        9: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:58:in `as_json'
        8: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `as_json'
        7: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `each'
        6: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:175:in `block in as_json'
        5: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `as_json'
        4: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:174:in `each'
        3: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:175:in `block in as_json'
        2: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/json.rb:58:in `as_json'
        1: from /usr/local/bundle/gems/activesupport-6.1.4.1/lib/active_support/core_ext/object/instance_variables.rb:15:in `instance_values'
SystemStackError (stack level too deep)

Using to_h on the response still works though on both versions.

[mszyndel]

After a quick investigation, breaking change seems to have been introduced in this commit https://github.com/github/graphql-client/commit/01fcb5891ff5782d893ba4bac9840c3875a3440c

[afrimdev]

@navied is there any updates on this issue?

[suusan2go]

This error happens because now ObjectClass class has definer variable that has circular references.

response.data.instance_values["definer"].instance_values["klass"].instance_values["null_type"].instance_values["of_klass"].instance_values["null_type"].instance_values["of_klass"]

https://github.com/github/graphql-client/blob/d19333d9587d7b187bba1f2339dc09a52067f8be/lib/graphql/client/schema/object_type.rb#L177-L187

ActiveSupport(as_json) tries to call instance_values if object doesn't have to_hash methods. Therefore this SystemStackError happnes.

class Object
 def as_json(options = nil) # :nodoc:
   if respond_to?(:to_hash)
     to_hash.as_json(options)
   else
     instance_values.as_json(options)
   end
 end
end

https://github.com/rails/rails/blob/3fcadfb7cf95e4a7e0bf9795019d4de212de97b0/activesupport/lib/active_support/core_ext/object/json.rb#L58-L66

I'm trying to fix this in this PR https://github.com/github/graphql-client/pull/281