Support symbol properties on extension objects

src/jsutils/ObjMap.ts

@@ -1,13 +1,13 @@
 export interface ObjMap<T> {
-  [key: string]: T;
+  [key: string | symbol]: T;
 }
 
-export type ObjMapLike<T> = ObjMap<T> | { [key: string]: T };
+export type ObjMapLike<T> = ObjMap<T> | { [key: string | symbol]: T };
 
 export interface ReadOnlyObjMap<T> {
-  readonly [key: string]: T;
+  readonly [key: string | symbol]: T;
 }
 
 export type ReadOnlyObjMapLike<T> =
   | ReadOnlyObjMap<T>
-  | { readonly [key: string]: T };
+  | { readonly [key: string | symbol]: T };

src/jsutils/toObjMap.ts

@@ -16,5 +16,10 @@ export function toObjMap<T>(
   for (const [key, value] of Object.entries(obj)) {
     map[key] = value;
   }
+
+  for (const key of Object.getOwnPropertySymbols(obj)) {
+    map[key] = obj[key];
+  }
+
   return map;
 }

src/type/__tests__/definition-test.ts

@@ -86,6 +86,25 @@ describe('Type System: Scalars', () => {
     expect(someScalar.toConfig()).to.deep.equal(someScalarConfig);
   });
 
+  it('supports symbol extensions', () => {
+    const test = Symbol.for('test');
+    const someScalarConfig: GraphQLScalarTypeConfig<unknown, unknown> = {
+      name: 'SomeScalar',
+      description: 'SomeScalar description.',
+      specifiedByURL: 'https://example.com/foo_spec',
+      serialize: passThroughFunc,
+      parseValue: passThroughFunc,
+      parseLiteral: passThroughFunc,
+      coerceInputLiteral: passThroughFunc,
+      valueToLiteral: passThroughFunc,
+      extensions: { [test]: 'extension' },
+      astNode: dummyAny,
+      extensionASTNodes: [dummyAny],
+    };
+    const someScalar = new GraphQLScalarType(someScalarConfig);
+    expect(someScalar.toConfig()).to.deep.equal(someScalarConfig);
+  });
+
   it('provides default methods if omitted', () => {
     const scalar = new GraphQLScalarType({ name: 'Foo' });
 

src/type/definition.ts

@@ -511,7 +511,7 @@ export function resolveObjMapThunk<T>(thunk: ThunkObjMap<T>): ObjMap<T> {
  * an object which can contain all the values you need.
  */
 export interface GraphQLScalarTypeExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**
@@ -725,7 +725,7 @@ interface GraphQLScalarTypeNormalizedConfig<TInternal, TExternal>
  * you may find them useful.
  */
 export interface GraphQLObjectTypeExtensions<_TSource = any, _TContext = any> {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**
@@ -980,7 +980,7 @@ export interface GraphQLResolveInfo {
  * you may find them useful.
  */
 export interface GraphQLFieldExtensions<_TSource, _TContext, _TArgs = any> {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 export interface GraphQLFieldConfig<TSource, TContext, TArgs = any> {
@@ -1008,7 +1008,7 @@ export type GraphQLFieldConfigArgumentMap = ObjMap<GraphQLArgumentConfig>;
  * an object which can contain all the values you need.
  */
 export interface GraphQLArgumentExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 export interface GraphQLArgumentConfig {
@@ -1085,7 +1085,7 @@ export function defineDefaultValue(
  * an object which can contain all the values you need.
  */
 export interface GraphQLInterfaceTypeExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**
@@ -1206,7 +1206,7 @@ interface GraphQLInterfaceTypeNormalizedConfig<TSource, TContext>
  * an object which can contain all the values you need.
  */
 export interface GraphQLUnionTypeExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**
@@ -1324,7 +1324,7 @@ interface GraphQLUnionTypeNormalizedConfig
  * an object which can contain all the values you need.
  */
 export interface GraphQLEnumTypeExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 function enumValuesFromConfig(values: GraphQLEnumValueConfigMap) {
@@ -1559,7 +1559,7 @@ export type GraphQLEnumValueConfigMap /* <T> */ =
  * an object which can contain all the values you need.
  */
 export interface GraphQLEnumValueExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 export interface GraphQLEnumValueConfig {
@@ -1589,7 +1589,7 @@ export interface GraphQLEnumValue {
  * an object which can contain all the values you need.
  */
 export interface GraphQLInputObjectTypeExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**
@@ -1718,7 +1718,7 @@ interface GraphQLInputObjectTypeNormalizedConfig
  * an object which can contain all the values you need.
  */
 export interface GraphQLInputFieldExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 export interface GraphQLInputFieldConfig {

src/type/directives.ts

@@ -44,7 +44,7 @@ export function assertDirective(directive: unknown): GraphQLDirective {
  * an object which can contain all the values you need.
  */
 export interface GraphQLDirectiveExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**

src/type/schema.ts

@@ -61,7 +61,7 @@ export function assertSchema(schema: unknown): GraphQLSchema {
  * an object which can contain all the values you need.
  */
 export interface GraphQLSchemaExtensions {
-  [attributeName: string]: unknown;
+  [attributeName: string | symbol]: unknown;
 }
 
 /**