Fix sprintf for undefined format strings

jasonkarns · jasonkarns · commit 30f85acb84d9 · 2020-06-05T11:50:17.000-04:00
Since we remove all the ERROR_MESSAGES and LOG_MESSAGES format strings,
the sprintf format function blows up when the format string is
undefined. This proxy allows us to return a dummy format string
regardless which "getter" property is accessed on those message objects.

The dummy format string returned uses three placeholders; which should
cover nearly all (if not all) possible invocations of the sprintf
function (having a placeholder for up to 3 arguments). This way the
sprintf function will basically operate as a "to-string" on all the
arguments provided.
diff --git a/packages/optimizely-sdk/ext/enums.js b/packages/optimizely-sdk/ext/enums.js
@@ -1,16 +1,12 @@
-var jsSdkUtils = require('@optimizely/js-sdk-utils')
+const NOTIFICATION_TYPES = require('@optimizely/js-sdk-utils').NOTIFICATION_TYPES
 
 const JAVASCRIPT_CLIENT_ENGINE = 'javascript-sdk'
 const NODE_CLIENT_ENGINE = 'node-sdk'
 const REACT_CLIENT_ENGINE = 'react-sdk'
 const REACT_NATIVE_CLIENT_ENGINE = 'react-native-sdk'
 const REACT_NATIVE_JS_CLIENT_ENGINE = 'react-native-js-sdk'
 
-// The normal utils.sprintf accepts the format string as first param.
-// That string will be undefined for the strings stubbed by this file (ie,
-// ERROR_MESSAGES and LOG_MESSAGES, etc). So we override the sprintf function
-// to just splat out the args instead of attempting to invoke .replace on it.
-jsSdkUtils.sprintf = (...args) => args.toString()
+const allEmptyString = new Proxy({}, { get: () => '%s; %s; %s' });
 
 module.exports = {
   LOG_LEVEL: {
@@ -21,9 +17,9 @@ module.exports = {
     ERROR: 4
   },
 
-  ERROR_MESSAGES: {},
+  ERROR_MESSAGES: allEmptyString,
 
-  LOG_MESSAGES: {},
+  LOG_MESSAGES: allEmptyString,
 
   RESERVED_EVENT_KEYWORDS: {
     REVENUE: 'revenue',
@@ -52,7 +48,7 @@ module.exports = {
     REACT_NATIVE_JS_CLIENT_ENGINE,
   ],
 
-  NOTIFICATION_TYPES: jsSdkUtils.NOTIFICATION_TYPES,
+  NOTIFICATION_TYPES,
 
   DECISION_NOTIFICATION_TYPES: {
     AB_TEST: 'ab-test',
