[validator] Add suggested types to incorrect field message

Related GraphQL-js commit: graphql/graphql-js@7861b22

Author: syrusakbary

graphql/core/validation/rules/fields_on_correct_type.py

@@ -1,4 +1,7 @@
+from collections import Counter
+
 from ...error import GraphQLError
+from ...type.definition import is_abstract_type, GraphQLObjectType
 from .base import ValidationRule
 
 
@@ -11,11 +14,50 @@ def enter_Field(self, node, key, parent, path, ancestors):
 
         field_def = self.context.get_field_def()
         if not field_def:
+            suggested_types = []
+            if is_abstract_type(type):
+                suggested_types = get_sibling_interfaces_including_field(type, node.name.value)
+                suggested_types += get_implementations_including_field(type, node.name.value)
             self.context.report_error(GraphQLError(
-                self.undefined_field_message(node.name.value, type.name),
+                self.undefined_field_message(node.name.value, type.name, suggested_types),
                 [node]
             ))
 
     @staticmethod
-    def undefined_field_message(field_name, type):
-        return 'Cannot query field "{}" on "{}".'.format(field_name, type)
+    def undefined_field_message(field_name, type, suggested_types):
+        message = 'Cannot query field "{}" on type "{}".'.format(field_name, type)
+        MAX_LENGTH = 5
+        if suggested_types:
+            suggestions = ', '.join(['"{}"'.format(t) for t in suggested_types[:MAX_LENGTH]])
+            l_suggested_types = len(suggested_types)
+            if l_suggested_types > MAX_LENGTH:
+                suggestions += ", and {} other types".format(l_suggested_types-MAX_LENGTH)
+            message += " However, this field exists on {}.".format(suggestions)
+            message += " Perhaps you meant to use an inline fragment?"
+        return message
+
+
+def get_implementations_including_field(type, field_name):
+    '''Return implementations of `type` that include `fieldName` as a valid field.'''
+    return sorted(map(lambda t: t.name, filter(lambda t: field_name in t.get_fields(), type.get_possible_types())))
+
+
+def get_sibling_interfaces_including_field(type, field_name):
+    '''Go through all of the implementations of type, and find other interaces
+    that they implement. If those interfaces include `field` as a valid field,
+    return them, sorted by how often the implementations include the other
+    interface.'''
+
+    implementing_objects = filter(lambda t: isinstance(t, GraphQLObjectType), type.get_possible_types())
+    suggested_interfaces = Counter()
+    for t in implementing_objects:
+        print t.name
+        for i in t.get_interfaces():
+            print i.name
+            if field_name not in i.get_fields():
+                break
+            suggested_interfaces[i.name] += 1
+    most_common = suggested_interfaces.most_common()
+    if not most_common:
+        return []
+    return list(zip(*most_common)[0])

tests/core_validation/test_fields_on_correct_type.py

@@ -3,9 +3,9 @@
 from .utils import expect_fails_rule, expect_passes_rule
 
 
-def undefined_field(field, type, line, column):
+def undefined_field(field, type, suggestions, line, column):
     return {
-        'message': FieldsOnCorrectType.undefined_field_message(field, type),
+        'message': FieldsOnCorrectType.undefined_field_message(field, type, suggestions),
         'locations': [SourceLocation(line, column)]
     }
 
@@ -71,8 +71,8 @@ def test_reports_errors_when_type_is_known_again():
         }
       },
     ''', [
-        undefined_field('unknown_pet_field', 'Pet', 3, 9),
-        undefined_field('unknown_cat_field', 'Cat', 5, 13)
+        undefined_field('unknown_pet_field', 'Pet', [], 3, 9),
+        undefined_field('unknown_cat_field', 'Cat', [], 5, 13)
     ])
 
 
@@ -82,7 +82,7 @@ def test_field_not_defined_on_fragment():
         meowVolume
       }
     ''', [
-        undefined_field('meowVolume', 'Dog', 3, 9)
+        undefined_field('meowVolume', 'Dog', [], 3, 9)
     ])
 
 
@@ -94,7 +94,7 @@ def test_ignores_deeply_unknown_field():
         }
       }
     ''', [
-        undefined_field('unknown_field', 'Dog', 3, 9)
+        undefined_field('unknown_field', 'Dog', [], 3, 9)
     ])
 
 
@@ -106,7 +106,7 @@ def test_sub_field_not_defined():
         }
       }
     ''', [
-        undefined_field('unknown_field', 'Pet', 4, 11)
+        undefined_field('unknown_field', 'Pet', [], 4, 11)
     ])
 
 
@@ -118,7 +118,7 @@ def test_field_not_defined_on_inline_fragment():
         }
       }
     ''', [
-        undefined_field('meowVolume', 'Dog', 4, 11)
+        undefined_field('meowVolume', 'Dog', [], 4, 11)
     ])
 
 
@@ -128,7 +128,7 @@ def test_aliased_field_target_not_defined():
         volume : mooVolume
       }
     ''', [
-        undefined_field('mooVolume', 'Dog', 3, 9)
+        undefined_field('mooVolume', 'Dog', [], 3, 9)
     ])
 
 
@@ -138,7 +138,7 @@ def test_aliased_lying_field_target_not_defined():
         barkVolume : kawVolume
       }
     ''', [
-        undefined_field('kawVolume', 'Dog', 3, 9)
+        undefined_field('kawVolume', 'Dog', [], 3, 9)
     ])
 
 
@@ -148,7 +148,7 @@ def test_not_defined_on_interface():
         tailLength
       }
     ''', [
-        undefined_field('tailLength', 'Pet', 3, 9)
+        undefined_field('tailLength', 'Pet', [], 3, 9)
     ])
 
 
@@ -158,7 +158,7 @@ def test_defined_on_implementors_but_not_on_interface():
         nickname
       }
     ''', [
-        undefined_field('nickname', 'Pet', 3, 9)
+        undefined_field('nickname', 'Pet', ['Cat', 'Dog'], 3, 9)
     ])
 
 
@@ -176,7 +176,7 @@ def test_direct_field_selection_on_union():
         directField
       }
     ''', [
-        undefined_field('directField', 'CatOrDog', 3, 9)
+        undefined_field('directField', 'CatOrDog', [], 3, 9)
     ])
 
 
@@ -186,7 +186,13 @@ def test_defined_on_implementors_queried_on_union():
         name
       }
     ''', [
-        undefined_field('name', 'CatOrDog', 3, 9)
+        undefined_field(
+          'name',
+          'CatOrDog',
+          ['Being', 'Pet', 'Canine', 'Cat', 'Dog'],
+          3,
+          9
+        )
     ])
 
 
@@ -201,3 +207,27 @@ def test_valid_field_in_inline_fragment():
         }
       }
     ''')
+
+
+def test_fields_correct_type_no_suggestion():
+    message = FieldsOnCorrectType.undefined_field_message('T', 'f', [])
+    assert message == 'Cannot query field "T" on type "f".'
+
+
+def test_fields_correct_type_no_small_number_suggestions():
+    message = FieldsOnCorrectType.undefined_field_message('T', 'f', ['A', 'B'])
+    assert message == (
+      'Cannot query field "T" on type "f". ' +
+      'However, this field exists on "A", "B". ' +
+      'Perhaps you meant to use an inline fragment?'
+    )
+
+
+def test_fields_correct_type_lot_suggestions():
+    message = FieldsOnCorrectType.undefined_field_message('T', 'f', ['A', 'B', 'C', 'D', 'E', 'F'])
+    assert message == (
+      'Cannot query field "T" on type "f". ' +
+      'However, this field exists on "A", "B", "C", "D", "E", ' +
+      'and 1 other types. '+
+      'Perhaps you meant to use an inline fragment?'
+    )

tests/core_validation/test_validation.py

@@ -49,6 +49,6 @@ def test_validates_using_a_custom_type_info():
     )
 
     assert len(errors) == 3
-    assert errors[0].message == 'Cannot query field "catOrDog" on "QueryRoot".'
-    assert errors[1].message == 'Cannot query field "furColor" on "Cat".'
-    assert errors[2].message == 'Cannot query field "isHousetrained" on "Dog".'
+    assert errors[0].message == 'Cannot query field "catOrDog" on type "QueryRoot".'
+    assert errors[1].message == 'Cannot query field "furColor" on type "Cat".'
+    assert errors[2].message == 'Cannot query field "isHousetrained" on type "Dog".'

tests/core_validation/utils.py

@@ -24,6 +24,12 @@
     }),
 })
 
+Canine = GraphQLInterfaceType('Canine', {
+    'name': GraphQLField(GraphQLString, {
+        'surname': GraphQLArgument(GraphQLBoolean),
+    }),
+})
+
 DogCommand = GraphQLEnumType('DogCommand', {
     'SIT': GraphQLEnumValue(0),
     'HEEL': GraphQLEnumValue(1),
@@ -53,13 +59,14 @@
             'y': GraphQLArgument(GraphQLInt)
         }
     )
-}, interfaces=[Being, Pet], is_type_of=lambda: None)
+}, interfaces=[Being, Pet, Canine], is_type_of=lambda: None)
 
 Cat = GraphQLObjectType('Cat', lambda: {
     'furColor': GraphQLField(FurColor),
     'name': GraphQLField(GraphQLString, {
         'surname': GraphQLArgument(GraphQLBoolean),
-    })
+    }),
+    'nickname': GraphQLField(GraphQLString),
 }, interfaces=[Being, Pet], is_type_of=lambda: None)
 
 CatOrDog = GraphQLUnionType('CatOrDog', [Dog, Cat])