diff --git a/config/initializers/graphql.rb b/config/initializers/graphql.rb
index 188d515dd..843fe2c00 100644
--- a/config/initializers/graphql.rb
+++ b/config/initializers/graphql.rb
@@ -1,7 +1,8 @@
 API_TYPE_DEFINITIONS = {
   User     => %I[ id username proposals ],
   Debate   => %I[ id title description author_id author created_at ],
-  Proposal => %I[ id title description author_id author created_at ]
+  Proposal => %I[ id title description author_id author created_at ],
+  Comment  => %I[ id body author_id author commentable_id commentable]
 }
 
 api_types = {}
diff --git a/spec/lib/graphql_spec.rb b/spec/lib/graphql_spec.rb
new file mode 100644
index 000000000..2369df348
--- /dev/null
+++ b/spec/lib/graphql_spec.rb
@@ -0,0 +1,68 @@
+require 'rails_helper'
+
+describe GraphQL::TypeCreator do
+  let!(:api_types) { {} }
+  let!(:user_type)    { GraphQL::TypeCreator.create(User, %I[ id ], api_types) }
+  let!(:comment_type) { GraphQL::TypeCreator.create(Comment, %I[ id ], api_types) }
+  let!(:debate_type)  { GraphQL::TypeCreator.create(Debate, %I[ id title author ], api_types) }
+  # TODO: no puedo añadir los comentarios a la field_list de Debate porque como
+  # las conexiones se crean de forma lazy creo que provoca que falle la creación
+  # del resto de tipos y provoca que fallen todos los tests.
+  # let!(:debate_type)  { GraphQL::TypeCreator.create(Debate, %I[ id title author comments ], api_types) }
+
+  describe "::create" do
+    describe "creates fields" do
+      it "for int attributes" do
+        created_field = debate_type.fields['id']
+
+        expect(created_field).to be_a(GraphQL::Field)
+        expect(created_field.type).to be_a(GraphQL::ScalarType)
+        expect(created_field.type.name).to eq('Int')
+      end
+
+      it "for string attributes" do
+        created_field = debate_type.fields['title']
+
+        expect(created_field).to be_a(GraphQL::Field)
+        expect(created_field.type).to be_a(GraphQL::ScalarType)
+        expect(created_field.type.name).to eq('String')
+      end
+    end
+
+    describe "creates connections for" do
+      it ":belongs_to associations" do
+        connection = debate_type.fields['author']
+
+        # TODO: because connection types are created and added  lazily to the
+        # api_types hash (with that proc thing ->) I don't really know how to
+        # test this.
+        # connection.class shows GraphQL::Field
+        # connection.inspect shows some weird info
+
+        expect(connection).to be_a(GraphQL::Field)
+        # expect(connection.type).to be_a(api_types[User])
+        expect(connection.name).to eq('author')
+      end
+
+      it ":has_one associations" do
+        skip "need to find association example that uses :has_one"
+      end
+
+      it ":has_many associations" do
+        skip "still don't know how to handle relay connections inside RSpec"
+
+        connection = debate_type.fields['comments']
+
+        # TODO: because connection types are created and added  lazily to the
+        # api_types hash (with that proc thing ->) I don't really know how to
+        # test this.
+        # connection.class shows GraphQL::Field
+        # connection.inspect shows some weird info
+
+        expect(connection).to be_a(GraphQL::Field)
+        # expect(created_connection.type).to be_a(api_types[Comment])
+        expect(connection.name).to eq('comments')
+      end
+    end
+  end
+end