fix: Fix potential property of undefined errors (#610)

Author: cwli24

package-lock.json

@@ -98,13 +98,18 @@ export function wrapJsonP (sharedEE) {
     return matches ? matches[1] : null
   }
 
+  /**
+   * Traverse a nested object using a '.'-delimited string wherein each substring piece maps to each subsequent object property layer.
+   * @param {string} longKey
+   * @param {object} obj
+   * @returns The final nested object referred to by initial longKey.
+   */
   function discoverValue (longKey, obj) {
-    var matches = longKey.match(VALUE_REGEX)
-    var key = matches[1]
-    var remaining = matches[3]
-    if (!remaining) {
-      return obj[key]
-    }
+    if (!longKey) return obj // end of object recursion depth when no more key levels
+    const matches = longKey.match(VALUE_REGEX)
+    // if 'longKey' was not undefined, that is it at least had 1 level left, then the regexp would've at least matched 1st group
+    const key = matches[1]
+    const remaining = matches[3]
     return discoverValue(remaining, obj[key])
   }
 

src/common/wrap/wrap-jsonp.js

@@ -1,4 +1,5 @@
 import { FEATURE_NAMES } from '../../../loaders/features/features'
+import { gosNREUM } from '../../../common/window/nreum'
 
 /**
  * Get an array of flags required by downstream (NR UI) based on the features initialized in this agent
@@ -8,21 +9,24 @@ import { FEATURE_NAMES } from '../../../loaders/features/features'
  */
 export function getActivatedFeaturesFlags (agentId) {
   const flagArr = []
+  const newrelic = gosNREUM()
 
-  Object.keys(newrelic.initializedAgents[agentId].features).forEach(featName => {
-    switch (featName) {
-      case FEATURE_NAMES.ajax:
-        flagArr.push('xhr'); break
-      case FEATURE_NAMES.jserrors:
-        flagArr.push('err'); break
-      case FEATURE_NAMES.pageAction:
-        flagArr.push('ins'); break
-      case FEATURE_NAMES.sessionTrace:
-        flagArr.push('stn'); break
-      case FEATURE_NAMES.spa:
-        flagArr.push('spa'); break
-    }
-  })
+  try {
+    Object.keys(newrelic.initializedAgents[agentId].features).forEach(featName => {
+      switch (featName) {
+        case FEATURE_NAMES.ajax:
+          flagArr.push('xhr'); break
+        case FEATURE_NAMES.jserrors:
+          flagArr.push('err'); break
+        case FEATURE_NAMES.pageAction:
+          flagArr.push('ins'); break
+        case FEATURE_NAMES.sessionTrace:
+          flagArr.push('stn'); break
+        case FEATURE_NAMES.spa:
+          flagArr.push('spa'); break
+      }
+    })
+  } catch (e) {}
 
   return flagArr
 }