Merge pull request khamusa#4 from aaronklaassen/mutation-matchers

Mutation matchers

lib/rspec/graphql_matchers/have_a_field.rb

@@ -3,20 +3,16 @@
 module RSpec
   module GraphqlMatchers
     class HaveAField < BaseMatcher
-      def initialize(expected_field_name)
+      def initialize(expected_field_name, fields = :fields)
         @expected_field_name = expected_field_name.to_s
         @expected_field_type = @graph_object = nil
+        @fields = fields.to_sym
       end
 
       def matches?(graph_object)
         @graph_object = graph_object
 
-        unless @graph_object.respond_to?(:fields)
-          raise "Invalid object #{@graph_object} provided to have_a_field " \
-            'matcher. It does not seem to be a valid GraphQL object type.'
-        end
-
-        @actual_field = @graph_object.fields[@expected_field_name]
+        @actual_field = field_collection[@expected_field_name]
         valid_field? && types_match?(@actual_field.type, @expected_field_type)
       end
 
@@ -66,6 +62,23 @@ def of_type_description
       def describe_obj(field)
         field.respond_to?(:name) && field.name || field.inspect
       end
+
+      def field_collection
+        if @graph_object.respond_to?(@fields)
+          @graph_object.public_send(@fields)
+        else
+          raise "Invalid object #{@graph_object} provided to #{matcher_name} " \
+            'matcher. It does not seem to be a valid GraphQL object type.'
+        end
+      end
+
+      def matcher_name
+        case @fields
+        when :fields        then 'have_a_field'
+        when :input_fields  then 'have_an_input_field'
+        when :return_fields then 'have_a_return_field'
+        end
+      end
     end
   end
 end

lib/rspec/graphql_matchers/matchers.rb

@@ -19,5 +19,17 @@ def have_a_field(field_name)
       RSpec::GraphqlMatchers::HaveAField.new(field_name)
     end
     alias have_field have_a_field
+
+    # rubocop:disable Style/PredicateName
+    def have_an_input_field(field_name)
+      RSpec::GraphqlMatchers::HaveAField.new(field_name, :input_fields)
+    end
+    alias have_input_field have_an_input_field
+
+    # rubocop:disable Style/PredicateName
+    def have_a_return_field(field_name)
+      RSpec::GraphqlMatchers::HaveAField.new(field_name, :return_fields)
+    end
+    alias have_return_field have_a_return_field
   end
 end

spec/rspec/have_a_return_field_spec.rb

@@ -0,0 +1,88 @@
+require 'spec_helper'
+
+module RSpec::GraphqlMatchers
+  describe 'expect(a_type).to have_a_return_field(field_name).that_returns(a_type)' do
+    subject(:a_type) do
+      types_to_define = type_fields
+      GraphQL::Relay::Mutation.define do
+        name 'TestObject'
+
+        types_to_define.each do |fname, ftype|
+          return_field fname, ftype
+        end
+      end
+    end
+    let(:type_fields) { { 'id' => types.String, 'other' => !types.ID } }
+
+    it { is_expected.to have_a_return_field(:id) }
+
+    it 'passes when the type defines the field' do
+      expect(a_type).to have_a_return_field(:id)
+    end
+
+    it 'fails when the type does not define the expected field' do
+      expect(a_type).not_to have_a_return_field(:ids)
+    end
+
+    it 'fails with a failure message when the type does not define the field' do
+      expect { expect(a_type).to have_a_return_field(:ids) }
+        .to fail_with("expected #{a_type.name} to define field `ids`, but no field was found with that name.")
+    end
+
+    it 'provides a description' do
+      matcher = have_a_return_field(:id)
+      matcher.matches?(a_type)
+
+      expect(matcher.description).to eq('define field `id`')
+    end
+
+    it 'passes when the type defines the field with correct type as strings' do
+      expect(a_type).to have_a_return_field(:id).that_returns('String')
+      expect(a_type).to have_a_return_field('other').that_returns('ID!')
+    end
+
+    it 'passes when the type defines the field with correct type as graphql objects' do
+      expect(a_type).to have_a_return_field(:id).that_returns(types.String)
+      expect(a_type).to have_a_return_field('other').that_returns(!types.ID)
+    end
+
+    it 'fails when the type defines a field of the wrong type' do
+      expect { expect(a_type).to have_a_return_field(:id).returning('String!') }
+        .to fail_with(
+          "expected #{a_type.name} to define field `id` of type `String!`," \
+          ' but the field type was `String`.'
+        )
+
+      expect { expect(a_type).to have_a_return_field('other').returning(!types.Int) }
+        .to fail_with(
+          "expected #{a_type.name} to define field `other` of type `Int!`," \
+          ' but the field type was `ID!`.'
+        )
+    end
+
+    context 'when an invalid type is passed' do
+      let(:a_type) { double(to_s: 'InvalidObject') }
+
+      it 'fails with a Runtime error' do
+        expect { expect(a_type).to have_a_return_field(:id) }
+          .to raise_error(
+            RuntimeError,
+            'Invalid object InvalidObject provided to have_a_return_field matcher. ' \
+            'It does not seem to be a valid GraphQL object type.'
+          )
+      end
+    end
+
+    context 'when a field is found but it does not seem a valid graphql field' do
+      before do
+        allow(a_type.return_fields)
+          .to receive(:[]).and_return double(inspect: 'AnInvalidField')
+      end
+
+      it 'fails with a Runtime error' do
+        expect { expect(a_type).to have_a_return_field(:id).of_type(!types.Int) }
+          .to raise_error(RuntimeError)
+      end
+    end
+  end
+end

spec/rspec/have_an_input_field_matcher_spec.rb

@@ -0,0 +1,88 @@
+require 'spec_helper'
+
+module RSpec::GraphqlMatchers
+  describe 'expect(a_type).to have_an_input_field(field_name).that_returns(a_type)' do
+    subject(:a_type) do
+      types_to_define = type_fields
+      GraphQL::Relay::Mutation.define do
+        name 'TestObject'
+
+        types_to_define.each do |fname, ftype|
+          input_field fname, ftype
+        end
+      end
+    end
+    let(:type_fields) { { 'id' => types.String, 'other' => !types.ID } }
+
+    it { is_expected.to have_an_input_field(:id) }
+
+    it 'passes when the type defines the field' do
+      expect(a_type).to have_an_input_field(:id)
+    end
+
+    it 'fails when the type does not define the expected field' do
+      expect(a_type).not_to have_an_input_field(:ids)
+    end
+
+    it 'fails with a failure message when the type does not define the field' do
+      expect { expect(a_type).to have_an_input_field(:ids) }
+        .to fail_with("expected #{a_type.name} to define field `ids`, but no field was found with that name.")
+    end
+
+    it 'provides a description' do
+      matcher = have_an_input_field(:id)
+      matcher.matches?(a_type)
+
+      expect(matcher.description).to eq('define field `id`')
+    end
+
+    it 'passes when the type defines the field with correct type as strings' do
+      expect(a_type).to have_an_input_field(:id).that_returns('String')
+      expect(a_type).to have_an_input_field('other').that_returns('ID!')
+    end
+
+    it 'passes when the type defines the field with correct type as graphql objects' do
+      expect(a_type).to have_an_input_field(:id).that_returns(types.String)
+      expect(a_type).to have_an_input_field('other').that_returns(!types.ID)
+    end
+
+    it 'fails when the type defines a field of the wrong type' do
+      expect { expect(a_type).to have_an_input_field(:id).returning('String!') }
+        .to fail_with(
+          "expected #{a_type.name} to define field `id` of type `String!`," \
+          ' but the field type was `String`.'
+        )
+
+      expect { expect(a_type).to have_an_input_field('other').returning(!types.Int) }
+        .to fail_with(
+          "expected #{a_type.name} to define field `other` of type `Int!`," \
+          ' but the field type was `ID!`.'
+        )
+    end
+
+    context 'when an invalid type is passed' do
+      let(:a_type) { double(to_s: 'InvalidObject') }
+
+      it 'fails with a Runtime error' do
+        expect { expect(a_type).to have_an_input_field(:id) }
+          .to raise_error(
+            RuntimeError,
+            'Invalid object InvalidObject provided to have_an_input_field matcher. ' \
+            'It does not seem to be a valid GraphQL object type.'
+          )
+      end
+    end
+
+    context 'when a field is found but it does not seem a valid graphql field' do
+      before do
+        allow(a_type.input_fields)
+          .to receive(:[]).and_return double(inspect: 'AnInvalidField')
+      end
+
+      it 'fails with a Runtime error' do
+        expect { expect(a_type).to have_an_input_field(:id).of_type(!types.Int) }
+          .to raise_error(RuntimeError)
+      end
+    end
+  end
+end