update interface and add test

Author: jaredmixpanel

__tests__/index.test.js

@@ -12,6 +12,12 @@ test(`it calls MixpanelReactNative initialize`, async () => {
   expect(NativeModules.MixpanelReactNative.initialize).toBeCalledWith("token", false, {"$lib_version": "1.3.7", "mp_lib": "react-native"});
 });
 
+test(`it calls MixpanelReactNative initialize with optOut and superProperties`, async () => {
+  const mixpanel = new Mixpanel("token");
+  mixpanel.init(true, {"super": "property"})
+  expect(NativeModules.MixpanelReactNative.initialize).toBeCalledWith("token", true, {"$lib_version": "1.3.7", "mp_lib": "react-native", "super": "property"});
+});
+
 test(`it calls MixpanelReactNative setServerURL`, async () => {
   const mixpanel = await Mixpanel.init("token");
   mixpanel.setServerURL("https://api-eu.mixpanel.com");

index.d.ts

@@ -4,7 +4,7 @@ type MixpanelProperties = { [key: string]: MixpanelType };
 export class Mixpanel {
     constructor(token: string);
     static init(token: string, optOutTrackingDefault?: boolean): Promise<Mixpanel>;
-    init(optOutTrackingDefault?: boolean): Promise<void>;
+    init(optOutTrackingDefault?: boolean, superProperties?: MixpanelProperties): Promise<void>;
     setServerURL(serverURL: string): void;
     setLoggingEnabled(loggingEnabled: boolean): void;
     setUseIpAddressForGeolocation(useIpAddressForGeolocation: boolean): void;