fix(utils): Allow invalid path in getDirectiveExtensions (#6436)

Co-authored-by: Olaf Alexander <oalexander@indeed.com>

packages/utils/src/getDirectiveExtensions.ts

@@ -68,7 +68,7 @@ export function getDirectiveExtensions<
   if (directableObj.extensions) {
     let directivesInExtensions = directableObj.extensions;
     for (const pathSegment of pathToDirectivesInExtensions) {
-      directivesInExtensions = directivesInExtensions[pathSegment];
+      directivesInExtensions = directivesInExtensions?.[pathSegment];
     }
     if (directivesInExtensions != null) {
       for (const directiveNameProp in directivesInExtensions) {

packages/utils/tests/getDirectiveExtensions.spec.ts

@@ -0,0 +1,65 @@
+import { GraphQLObjectType } from 'graphql';
+import { getDirectiveExtensions } from '../src';
+
+describe('getDirectiveExtensions', () => {
+  it('should return directive extensions when they are in the directives path', () => {
+    const objectType = new GraphQLObjectType({
+      name: 'User',
+      fields: () => ({}),
+      extensions: {
+        directives: {
+          id: {},
+        },
+      },
+    });
+
+    const directiveExtensions = getDirectiveExtensions(objectType);
+    expect(directiveExtensions).toEqual(expect.objectContaining({ id: expect.any(Object) }));
+  });
+
+  it('should return directive extensions when they are in the a custom path', () => {
+    const objectType = new GraphQLObjectType({
+      name: 'TestObject',
+      fields: () => ({}),
+      extensions: {
+        custom: {
+          directives: {
+            path: {
+              id: {},
+            },
+          },
+        },
+      },
+    });
+
+    const directiveExtensions = getDirectiveExtensions(objectType, undefined, [
+      'custom',
+      'directives',
+      'path',
+    ]);
+    expect(directiveExtensions).toEqual(expect.objectContaining({ id: expect.any(Object) }));
+  });
+
+  it('should return no directive extensions when they are no defined', () => {
+    const objectType = new GraphQLObjectType({
+      name: 'TestObject',
+      fields: () => ({}),
+    });
+    const directiveExtensions = getDirectiveExtensions(objectType);
+    expect(directiveExtensions).toEqual({});
+  });
+
+  it('should return no directive extensions when an invalid extension path is given', () => {
+    const objectType = new GraphQLObjectType({
+      name: 'TestObject',
+      fields: () => ({}),
+    });
+    const directiveExtensions = getDirectiveExtensions(objectType, undefined, [
+      'not',
+      'a',
+      'real',
+      'path',
+    ]);
+    expect(directiveExtensions).toEqual({});
+  });
+});