Refactor API host resolution to use a common _getApiHost method for DRY implementation

- Added _getApiHost method to MixpanelLib prototype
- Updated all endpoint URL building to use this common method
- Maintains backward compatibility with existing api_host config
- Consistently handles per-endpoint host overrides

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: chrisknu

src/mixpanel-core.js

@@ -1207,9 +1207,7 @@ MixpanelLib.prototype.track = addOptOutCheckMixpanelLib(function (
     properties: properties,
   };
 
-  // Use api_hosts[events] if available, fall back to api_host
-  var api_host =
-    this.get_config("api_hosts")["events"] || this.get_config("api_host");
+  var api_host = this._getApiHost("events");
 
   var ret = this._track_or_batch(
     {
@@ -2066,6 +2064,17 @@ MixpanelLib.prototype.get_config = function (prop_name) {
   return this["config"][prop_name];
 };
 
+/**
+ * Get the API host for a specific endpoint type, falling back to the default api_host if not specified
+ * 
+ * @param {String} endpoint_type The type of endpoint (e.g., "events", "people", "groups")
+ * @returns {String} The API host to use for this endpoint
+ * @private
+ */
+MixpanelLib.prototype._getApiHost = function (endpoint_type) {
+  return this.get_config("api_hosts")[endpoint_type] || this.get_config("api_host");
+};
+
 /**
  * Fetch a hook function from config, with safe default, and run it
  * against the given arguments

src/mixpanel-group.js

@@ -169,9 +169,8 @@ MixpanelGroup.prototype._send_request = function (data, callback) {
 
   var date_encoded_data = _.encodeDates(data);
 
-  // Get api_host for groups endpoint if available, otherwise use default api_host
-  var api_host =
-    this._get_config("api_hosts")["groups"] || this._get_config("api_host");
+  // Get api_host for groups endpoint
+  var api_host = this._mixpanel._getApiHost("groups");
 
   return this._mixpanel._track_or_batch(
     {

src/mixpanel-people.js

@@ -390,9 +390,8 @@ MixpanelPeople.prototype._send_request = function (data, callback) {
     return _.truncate(date_encoded_data, 255);
   }
 
-  // Get api_host for people endpoint if available, otherwise use default api_host
-  var api_host =
-    this._get_config("api_hosts")["people"] || this._get_config("api_host");
+  // Get api_host for people endpoint
+  var api_host = this._mixpanel._getApiHost("people");
 
   return this._mixpanel._track_or_batch(
     {

src/recorder/session-recording.js

@@ -349,7 +349,7 @@ SessionRecording.prototype._sendRequest = function(currentReplayId, reqParams, r
             retryAfter: response.headers.get('Retry-After')
         });
     }.bind(this);
-    const apiHost = this.getConfig('session_recording_use_proxy') ? this.getConfig('api_host') : 'https://api.mixpanel.com';
+    const apiHost = this.getConfig('session_recording_use_proxy') ? this._mixpanel._getApiHost("record") : 'https://api.mixpanel.com';
 
     window['fetch'](apiHost + '/' + this.getConfig('api_routes')['record'] + '?' + new URLSearchParams(reqParams), {
         'method': 'POST',