fix: handle potentially undefined variables

Author: Phundrak

client/index.ts

@@ -2,11 +2,11 @@ import { defineClientConfig } from '@vuepress/client'
 
 declare let __UMAMI_ANALYTICS_ID__: string
 declare let __UMAMI_ANALYTICS_SRC__: string
-declare let __UMAMI_ANALYTICS_HOST_URL__: string | null
-declare let __UMAMI_ANALYTICS_AUTO_TRACK__: boolean | null
-declare let __UMAMI_ANALYTICS_DO_NOT_TRACK__: boolean | null
-declare let __UMAMI_ANALYTICS_CACHE__: boolean | null
-declare let __UMAMI_ANALYTICS_DOMAINS__: string[] | null
+declare let __UMAMI_ANALYTICS_HOST_URL__: undefined | string | null
+declare let __UMAMI_ANALYTICS_AUTO_TRACK__: undefined | boolean | null
+declare let __UMAMI_ANALYTICS_DO_NOT_TRACK__: undefined | boolean | null
+declare let __UMAMI_ANALYTICS_CACHE__: undefined | boolean | null
+declare let __UMAMI_ANALYTICS_DOMAINS__: undefined | string[] | null
 
 export default defineClientConfig({
   enhance: () => {
@@ -18,25 +18,25 @@ export default defineClientConfig({
     scriptTag.async = true
     scriptTag.src = __UMAMI_ANALYTICS_SRC__
     scriptTag.setAttribute('data-website-id', __UMAMI_ANALYTICS_ID__)
-    if (__UMAMI_ANALYTICS_HOST_URL__ !== null) {
+    if (__UMAMI_ANALYTICS_HOST_URL__) {
       scriptTag.setAttribute('data-host-url', __UMAMI_ANALYTICS_HOST_URL__)
     }
-    if (__UMAMI_ANALYTICS_AUTO_TRACK__ !== null) {
+    if (__UMAMI_ANALYTICS_AUTO_TRACK__) {
       scriptTag.setAttribute(
         'data-auto-track',
         '' + __UMAMI_ANALYTICS_AUTO_TRACK__,
       )
     }
-    if (__UMAMI_ANALYTICS_DO_NOT_TRACK__ !== null) {
+    if (__UMAMI_ANALYTICS_DO_NOT_TRACK__) {
       scriptTag.setAttribute(
         'data-do-not-track',
         '' + __UMAMI_ANALYTICS_DO_NOT_TRACK__,
       )
     }
-    if (__UMAMI_ANALYTICS_CACHE__ !== null) {
+    if (__UMAMI_ANALYTICS_CACHE__) {
       scriptTag.setAttribute('data-cache', '' + __UMAMI_ANALYTICS_CACHE__)
     }
-    if (__UMAMI_ANALYTICS_DOMAINS__ !== null) {
+    if (__UMAMI_ANALYTICS_DOMAINS__) {
       scriptTag.setAttribute(
         'data-domains',
         __UMAMI_ANALYTICS_DOMAINS__.join(','),