Suggested valid type names

graphql · Apr 12, 2016 · d460b74 · d460b74
1 parent e25fe3e
commit d460b74
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Showing 2 changed files with 70 additions and 11 deletions.
diff --git a/src/validation/__tests__/KnownTypeNames-test.js b/src/validation/__tests__/KnownTypeNames-test.js
@@ -15,9 +15,9 @@ import {
 } from '../rules/KnownTypeNames';
 
 
-function unknownType(typeName, line, column) {
+function unknownType(typeName, suggestedTypes, line, column) {
   return {
-    message: unknownTypeMessage(typeName),
+    message: unknownTypeMessage(typeName, suggestedTypes),
     locations: [ { line, column } ],
   };
 }
@@ -49,9 +49,39 @@ describe('Validate: Known type names', () => {
         name
       }
     `, [
-      unknownType('JumbledUpLetters', 2, 23),
-      unknownType('Badger', 5, 25),
-      unknownType('Peettt', 8, 29)
+      unknownType(
+        'JumbledUpLetters',
+        [ 'ComplexInput',
+          'ComplicatedArgs',
+          'QueryRoot',
+          'Intelligent',
+          'HumanOrAlien'
+        ],
+        2,
+        23
+      ),
+      unknownType(
+        'Badger',
+        [ 'Dog',
+          'Boolean',
+          'Pet',
+          'Alien',
+          'Being'
+        ],
+        5,
+        25
+      ),
+      unknownType(
+        'Peettt',
+        [ 'Pet',
+          'Float',
+          'Being',
+          'Cat',
+          'Int'
+        ],
+        8,
+        29
+      )
     ]);
   });
 
@@ -73,7 +103,17 @@ describe('Validate: Known type names', () => {
         }
       }
     `, [
-      unknownType('NotInTheSchema', 12, 23),
+      unknownType(
+        'NotInTheSchema',
+        [ '__Schema',
+          'Intelligent',
+          'HumanOrAlien',
+          'Int',
+          'Canine'
+        ],
+        12,
+        23
+      ),
     ]);
   });
 

diff --git a/src/validation/rules/KnownTypeNames.js b/src/validation/rules/KnownTypeNames.js
@@ -11,10 +11,22 @@
 import type { ValidationContext } from '../index';
 import { GraphQLError } from '../../error';
 import type { GraphQLType } from '../../type/definition';
+import { suggestionList } from '../../utilities/suggestionList';
 
-
-export function unknownTypeMessage(type: GraphQLType): string {
-  return `Unknown type "${type}".`;
+export function unknownTypeMessage(
+  type: GraphQLType,
+  suggestedTypes: Arrray<string>
+): string {
+  let message = `Unknown type "${type}".`;
+  const MAX_LENGTH = 5;
+  if (suggestedTypes.length) {
+    const suggestions = suggestedTypes
+      .slice(0, MAX_LENGTH)
+      .map(t => `"${t}"`)
+      .join(', ');
+    message += ` Perhaps you meant one of the following: ${suggestions}.`;
+  }
+  return message;
 }
 
 /**
@@ -33,11 +45,18 @@ export function KnownTypeNames(context: ValidationContext): any {
     UnionTypeDefinition: () => false,
     InputObjectTypeDefinition: () => false,
     NamedType(node) {
+      const schema = context.getSchema();
       const typeName = node.name.value;
-      const type = context.getSchema().getType(typeName);
+      const type = schema.getType(typeName);
       if (!type) {
         context.reportError(
-          new GraphQLError(unknownTypeMessage(typeName), [ node ])
+          new GraphQLError(
+            unknownTypeMessage(
+              typeName,
+              suggestionList(typeName, Object.keys(schema.getTypeMap()))
+            ),
+            [ node ]
+          )
         );
       }
     }