Merge pull request #59 from FormidableLabs/fix-ssr-detection

Fix SSR detection

src/exchange.ssr.test.ts

@@ -0,0 +1,22 @@
+/**
+ * @jest-environment node
+ */
+import { fromValue } from 'wonka';
+import * as messengers from './utils';
+
+const createNativeMessenger = jest.spyOn(messengers, 'createNativeMessenger');
+const createBrowserMessenger = jest.spyOn(messengers, 'createBrowserMessenger');
+
+it('returns forwarding exchange', () => {
+  (global as any).window = undefined;
+  const { devtoolsExchange } = require('./exchange'); // eslint-disable-line
+  expect(createNativeMessenger).toBeCalledTimes(0);
+  expect(createBrowserMessenger).toBeCalledTimes(0);
+
+  const value = fromValue('Heloo');
+  const forward = jest.fn();
+
+  devtoolsExchange({ forward })(value);
+  expect(forward).toBeCalledTimes(1);
+  expect(forward).toBeCalledWith(value);
+});

src/exchange.ts

@@ -143,8 +143,9 @@ const messageHandlers = {
 } as const;
 
 export const devtoolsExchange = ((): Exchange => {
-  const isNative = navigator?.product === 'ReactNative';
-  const isSSR = !isNative && typeof window === undefined;
+  const isNative =
+    typeof navigator !== 'undefined' && navigator?.product === 'ReactNative';
+  const isSSR = !isNative && typeof window === 'undefined';
 
   // Prod or SSR
   if (process.env.NODE_ENV === 'production' || isSSR) {