Allow additional legacy names when extending a schema.

Author: alloy

src/utilities/__tests__/extendSchema-test.js

@@ -1225,18 +1225,23 @@ describe('extendSchema', () => {
       query: new GraphQLObjectType({
         name: 'Query',
         fields: () => ({
-          id: { type: GraphQLID },
+          __badName: { type: GraphQLString },
         }),
       }),
       allowedLegacyNames: ['__badName'],
     });
     const ast = parse(`
       extend type Query {
-        __badName: String
+        __anotherBadName: String
       }
     `);
-    const schema = extendSchema(testSchemaWithLegacyNames, ast);
-    expect(schema.__allowedLegacyNames).to.deep.equal(['__badName']);
+    const schema = extendSchema(testSchemaWithLegacyNames, ast, {
+      allowedLegacyNames: ['__anotherBadName'],
+    });
+    expect(schema.__allowedLegacyNames).to.deep.equal([
+      '__badName',
+      '__anotherBadName',
+    ]);
   });
 
   describe('does not allow extending a non-object type', () => {

src/utilities/extendSchema.js

@@ -58,8 +58,9 @@ type Options = {|
 
   /**
    * If provided, the schema will consider fields or types with names included
-   * in this list valid, even if they do not adhere to the specification's
-   * schema validation rules.
+   * in this list valid, in addition to those already allowed on the original
+   * schema, even if they do not adhere to the specification's schema validation
+   * rules.
    *
    * This option is provided to ease adoption and may be removed in a future
    * major release.
@@ -255,6 +256,14 @@ export function extendSchema(
     types.push(definitionBuilder.buildType(typeName));
   });
 
+  let allowedLegacyNames = [
+    ...(schema.__allowedLegacyNames || []),
+    ...((options && options.allowedLegacyNames) || []),
+  ];
+  if (allowedLegacyNames.length === 0) {
+    allowedLegacyNames = null;
+  }
+
   // Then produce and return a Schema with these types.
   return new GraphQLSchema({
     query: queryType,
@@ -263,8 +272,7 @@ export function extendSchema(
     types,
     directives: getMergedDirectives(),
     astNode: schema.astNode,
-    allowedLegacyNames:
-      schema.__allowedLegacyNames && schema.__allowedLegacyNames.slice(),
+    allowedLegacyNames,
   });
 
   function appendExtensionToTypeExtensions(