fix: check TypeComposer via class name

Author: nodkz

package.json

@@ -42,7 +42,7 @@
     "eslint-plugin-prettier": "^2.6.0",
     "flow-bin": "^0.65.0",
     "graphql": "0.13.0",
-    "graphql-compose": "^3.0.0-beta.2",
+    "graphql-compose": "^3.0.0-beta.3",
     "jest": "^22.2.1",
     "prettier": "^1.10.2",
     "rimraf": "^2.6.2",

src/composeWithConnection.js

@@ -14,7 +14,7 @@ export function composeWithConnection(
   typeComposer: TypeComposer,
   opts: ComposeWithConnectionOpts
 ): TypeComposer {
-  if (!(typeComposer instanceof TypeComposer)) {
+  if (!typeComposer || typeComposer.constructor.name !== 'TypeComposer') {
     throw new Error('You should provide TypeComposer instance to composeWithRelay method');
   }
 

src/connectionResolver.js

@@ -67,7 +67,7 @@ export function prepareConnectionResolver<TSource, TContext>(
   typeComposer: TypeComposer,
   opts: ComposeWithConnectionOpts
 ): Resolver<TSource, TContext> {
-  if (!(typeComposer instanceof TypeComposer)) {
+  if (!typeComposer || typeComposer.constructor.name !== 'TypeComposer') {
     throw new Error('First arg for prepareConnectionResolver() should be instance of TypeComposer');
   }