Safeguard against missing performance csv file

Author: Chalarangelo

Diff for: lib/performanceTracking.js

@@ -4,18 +4,23 @@ import settings from '../config/settings.js';
 
 export default class PerforanceTracking {
   static {
-    const csvData = fs.readFileSync(settings.paths.pagePerformanceCSV, 'utf8');
-    this.data = csvData
-      .split('\n')
-      .map(row => row.split(','))
-      .reduce((acc, [key, clicks, impressions]) => {
-        const slug = key.replace(settings.website.url, '');
-        acc[slug] = {
-          clicks: Number.parseInt(clicks, 10),
-          impressions: Number.parseInt(impressions, 10),
-        };
-        return acc;
-      }, {});
+    if (fs.existsSync(settings.paths.pagePerformanceCSV)) {
+      const csvData = fs.readFileSync(
+        settings.paths.pagePerformanceCSV,
+        'utf8'
+      );
+      this.data = csvData
+        .split('\n')
+        .map(row => row.split(','))
+        .reduce((acc, [key, clicks, impressions]) => {
+          const slug = key.replace(settings.website.url, '');
+          acc[slug] = {
+            clicks: Number.parseInt(clicks, 10),
+            impressions: Number.parseInt(impressions, 10),
+          };
+          return acc;
+        }, {});
+    }
   }
 
   static for(...slugs) {