added validations to logEvent

Author: Salakar

lib/modules/analytics.js

@@ -3,6 +3,23 @@ import { NativeModules } from 'react-native';
 import { Base } from './base';
 
 const FirestackAnalytics = NativeModules.FirestackAnalytics;
+const AlphaNumericUnderscore = /^[a-zA-Z0-9_]+$/;
+
+const ReservedEventNames = [
+  'app_clear_data',
+  'app_uninstall',
+  'app_update',
+  'error',
+  'first_open',
+  'in_app_purchase',
+  'notification_dismiss',
+  'notification_foreground',
+  'notification_open',
+  'notification_receive',
+  'os_update',
+  'session_start',
+  'user_engagement',
+];
 
 export default class Analytics extends Base {
   /**
@@ -12,6 +29,25 @@ export default class Analytics extends Base {
    * @return {Promise}
    */
   logEvent(name: string, params: Object = {}): void {
+    // check name is not a reserved event name
+    if (ReservedEventNames.includes(name)) {
+      throw new Error(`event name '${name}' is a reserved event name and can not be used.`);
+    }
+
+    // name format validation
+    if (!AlphaNumericUnderscore.test(name)) {
+      throw new Error(`Event name '${name}' is invalid. Names should contain 1 to 32 alphanumeric characters or underscores.`);
+    }
+
+    // maximum number of allowed params check
+    if (Object.keys(params).length > 25) throw new Error('Maximum number of parameters exceeded (25).');
+
+    // TODO validate param names and values
+    // Parameter names can be up to 24 characters long and must start with an alphabetic character
+    // and contain only alphanumeric characters and underscores. Only String, long and double param
+    // types are supported. String parameter values can be up to 36 characters long. The "firebase_"
+    // prefix is reserved and should not be used for parameter names.
+
     return FirestackAnalytics.logEvent(name, params);
   }