Merge pull request rmosolgo#5268 from rmosolgo/fix-fields-will-merge-alias-on-fragment

Lookup the right field in FieldsWillMerge

Author: rmosolgo

lib/graphql/static_validation/rules/fields_will_merge.rb

@@ -345,7 +345,7 @@ def find_fields_and_fragments(selections, owner_type:, parents:, fields:, fragme
             fields << Field.new(node, definition, owner_type, parents)
           when GraphQL::Language::Nodes::InlineFragment
             fragment_type = node.type ? @types.type(node.type.name) : owner_type
-            find_fields_and_fragments(node.selections, parents: [*parents, fragment_type], owner_type: owner_type, fields: fields, fragment_spreads: fragment_spreads) if fragment_type
+            find_fields_and_fragments(node.selections, parents: [*parents, fragment_type], owner_type: fragment_type, fields: fields, fragment_spreads: fragment_spreads) if fragment_type
           when GraphQL::Language::Nodes::FragmentSpread
             fragment_spreads << FragmentSpread.new(node.name, parents)
           end

spec/graphql/static_validation/rules/fields_will_merge_spec.rb

@@ -998,4 +998,45 @@
       refute_match %r/\$arg12/, error_messages.first
     end
   end
+
+  describe "duplicate aliases on a interface with inline fragment spread" do
+    class DuplicateAliasesSchema < GraphQL::Schema
+      module Node
+        include GraphQL::Schema::Interface
+        field :id, ID
+
+        def self.resolve_type(obj, ctx)
+          Repository
+        end
+      end
+
+      class Repository < GraphQL::Schema::Object
+        implements Node
+        field :name, String
+        field :id, ID
+      end
+
+      class Query < GraphQL::Schema::Object
+        field :node, Node, fallback_value: { name: "graphql-ruby", id: "abcdef" }
+      end
+
+      query(Query)
+      orphan_types(Repository)
+    end
+
+    it "returns an error" do
+      query_str = 'query {
+        node {
+          ... on Repository {
+            info: name
+            info: id
+          }
+        }
+      }
+      '
+
+      res = DuplicateAliasesSchema.execute(query_str)
+      assert_equal ["Field 'info' has a field conflict: name or id?"], res["errors"].map { |e| e["message"] }
+    end
+  end
 end