Add Graph-QL testing support

spec/support/helpers/graphql_helpers.rb

@@ -105,12 +105,15 @@ module GraphqlHelpers
   end
 
   def query_graphql_field(name, attributes = {}, fields = nil)
-    fields ||= all_graphql_fields_for(name.classify)
-    attributes = attributes_to_graphql(attributes)
-    attributes = "(#{attributes})" if attributes.present?
+    field_params = if attributes.present?
+                     "(#{attributes_to_graphql(attributes)})" if attributes.present?
+                   else
+                     ''
+                   end
+
     <<~QUERY
-      #{name}#{attributes}
-      #{wrap_fields(fields)}
+      #{GraphqlHelpers.fieldnamerize(name.to_s)}#{field_params}
+      #{wrap_fields(fields || all_graphql_fields_for(name.to_s.classify))}
     QUERY
   end
 
@@ -301,6 +304,17 @@ module GraphqlHelpers
   def global_id_of(model)
     model.to_global_id.to_s
   end
+
+  def missing_required_argument(path, argument)
+    a_hash_including(
+      'path' => ['query'].concat(path),
+      'extensions' => a_hash_including('code' => 'missingRequiredArguments', 'arguments' => argument.to_s)
+    )
+  end
+
+  def custom_graphql_error(path, msg)
+    a_hash_including('path' => path, 'message' => msg)
+  end
 end
 
 # This warms our schema, doing this as part of loading the helpers to avoid

spec/support/matchers/graphql_matchers.rb

@@ -11,9 +11,23 @@ RSpec::Matchers.define :have_graphql_fields do |*expected|
     Array.wrap(expected).map { |name| GraphqlHelpers.fieldnamerize(name) }
   end
 
+  @allow_extra = false
+
+  chain :only do
+    @allow_extra = false
+  end
+
+  chain :at_least do
+    @allow_extra = true
+  end
+
   match do |kls|
+    if @allow_extra
+      expect(kls.fields.keys).to include(*expected_field_names)
+    else
       expect(kls.fields.keys).to contain_exactly(*expected_field_names)
     end
+  end
 
   failure_message do |kls|
     missing = expected_field_names - kls.fields.keys
@@ -22,7 +36,7 @@ RSpec::Matchers.define :have_graphql_fields do |*expected|
     message = []
 
     message << "is missing fields: <#{missing.inspect}>" if missing.any?
-    message << "contained unexpected fields: <#{extra.inspect}>" if extra.any?
+    message << "contained unexpected fields: <#{extra.inspect}>" if extra.any? && !@allow_extra
 
     message.join("\n")
   end

spec/support/shared_examples/graphql/failure_to_find_anything.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+# Shared example for legal queries that are expected to return nil.
+# Requires the following let bindings to be defined:
+#  - post_query: action to send the query
+#  - path: array of keys from query root to the result
+shared_examples 'a failure to find anything' do
+  it 'finds nothing' do
+    post_query
+
+    data = graphql_data.dig(*path)
+
+    expect(data).to be_nil
+  end
+end