1 files changed, 56 insertions, 0 deletions
diff --git a/spec/graphql/mutations/base_mutation_spec.rb b/spec/graphql/mutations/base_mutation_spec.rb
new file mode 100644
index 00000000000..7939fadb37b
--- /dev/null
+++ b/spec/graphql/mutations/base_mutation_spec.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe ::Mutations::BaseMutation do
+  include GraphqlHelpers
+
+  describe 'argument nullability' do
+    let_it_be(:user) { create(:user) }
+    let_it_be(:context)  { { current_user: user } }
+
+    subject(:mutation) { mutation_class.new(object: nil, context: context, field: nil) }
+
+    describe 'when using a mutation with correct argument declarations' do
+      context 'when argument is nullable and required' do
+        let(:mutation_class) do
+          Class.new(described_class) do
+            argument :foo, GraphQL::Types::String, required: :nullable
+          end
+        end
+
+        specify do
+          expect { subject.ready? }.to raise_error(ArgumentError, /must be provided: foo/)
+        end
+
+        specify do
+          expect { subject.ready?(foo: nil) }.not_to raise_error
+        end
+
+        specify do
+          expect { subject.ready?(foo: "bar") }.not_to raise_error
+        end
+      end
+
+      context 'when argument is required and NOT nullable' do
+        let(:mutation_class) do
+          Class.new(described_class) do
+            argument :foo, GraphQL::Types::String, required: true
+          end
+        end
+
+        specify do
+          expect { subject.ready? }.to raise_error(ArgumentError, /must be provided/)
+        end
+
+        specify do
+          expect { subject.ready?(foo: nil) }.to raise_error(ArgumentError, /must be provided/)
+        end
+
+        specify do
+          expect { subject.ready?(foo: "bar") }.not_to raise_error
+        end
+      end
+    end
+  end
+end