fix: region selection criteria should be configurable (#98)

Author: lukaszczerpak-cloudinary

config/default.js

@@ -37,6 +37,7 @@ const conf = {
     },
     timeout: process.env.WTP_TIMEOUT || 30000,
     "locationSelector": {
+      "allowRegex": process.env.WTP_LS_ALLOW_REGEX || '_US_',
       "cacheTtl": process.env.WTP_LS_CACHE_TTL || 10,
       "updateTimeout": process.env.WTP_LS_UPDATE_TIMEOUT || 20,
       "defaultLocation": process.env.WTP_LS_DEFAULT_LOCATION || "IAD_US_01"

wtp/apiCaller.js

@@ -70,7 +70,7 @@ const runWtpTest = async (url, mobile, cb) => {
             height: config.get('wtp.viewportHeight'),
             custom: config.get('wtp.imageScript'),
             location: await locationSelector.getLocation() + ':Chrome.Native', // Native means no speed shaping in browser, full speed ahead
-      mobile: (mobile) ? 1 : 0,
+            mobile: (mobile) ? 1 : 0,
             fvonly: 1, // first view only
             timeline: 1 // workaround for WPT sometimes hanging on getComputedStyle()
           },

wtp/locationSelector.js

@@ -31,6 +31,7 @@ class LocationSelector {
         if (!LocationSelector.instance) {
             this.cachedAllLocations = [];
             this.location = config.get('wtp.locationSelector.defaultLocation');
+            this.allowRegex = new RegExp(config.get('wtp.locationSelector.allowRegex'));
             this.lastUpdated = null;
             this.mutex = withTimeout(new Mutex(), config.get('wtp.locationSelector.updateTimeout') * 1000);
             LocationSelector.instance = this;
@@ -113,7 +114,7 @@ class LocationSelector {
         }
 
         const filtered = Object.keys(newLocations)
-            .filter(key => key.includes("_US_"))    // we only want US-based instances
+            .filter(key => this.allowRegex.test(key))
             .reduce((arr, key) => {
                 return [...arr, newLocations[key]];
             }, []);