Merge pull request #1934 from rmosolgo/fix-lookahead-invalid

Support lookahead on invalid queries
rmosolgo · Oct 30, 2018 · 4fa45fe · 4fa45fe
2 parents de70c58 + 6bb3a6e
commit 4fa45fe
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Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/lib/graphql/execution/lookahead.rb b/lib/graphql/execution/lookahead.rb
@@ -324,14 +324,14 @@ def flatten_ast_value(query, v)
       module FieldHelpers
         module_function
 
-        def get_field(schema, owner_type, field_name )
+        def get_field(schema, owner_type, field_name)
           field_defn = owner_type.get_field(field_name)
           field_defn ||= if owner_type == schema.query.metadata[:type_class] && (entry_point_field = schema.introspection_system.entry_point(name: field_name))
             entry_point_field.metadata[:type_class]
           elsif (dynamic_field = schema.introspection_system.dynamic_field(name: field_name))
             dynamic_field.metadata[:type_class]
           else
-            raise "Invariant: no field for #{owner_type}.#{field_name}"
+            nil
           end
 
           field_defn

diff --git a/spec/graphql/execution/lookahead_spec.rb b/spec/graphql/execution/lookahead_spec.rb
@@ -211,6 +211,13 @@ class Schema < GraphQL::Schema
       assert_equal 2, context[:lookahead_latin_name]
       assert_equal [:find_bird_species], context[:root_lookahead_names]
     end
+
+    it "works for invalid queries" do
+      context = {lookahead_latin_name: 0}
+      res = LookaheadTest::Schema.execute("{ doesNotExist }", context: context)
+      assert res.key?("errors")
+      assert_equal 0, context[:lookahead_latin_name]
+    end
   end
 
   describe '#selections' do