explicitly await loading of feature switches before loading the Editor (

#4216)

editor/src/templates/editor-entry-point.tsx

@@ -7,7 +7,8 @@
 import '../vite-shims'
 
 // import feature switches so they are loaded before anything else can read them
-import '../utils/feature-switches'
+import { loadFeatureSwitches } from '../utils/feature-switches'
+await loadFeatureSwitches()
 
 // Fire off server requests that later block, to improve initial load on slower connections. These will still block,
 // but this gives us a chance to cache the result first

editor/src/utils/feature-switches.ts

@@ -47,25 +47,45 @@ let FeatureSwitches: { [feature in FeatureName]: boolean } = {
   'Debug - Print UIDs': false,
 }
 
+let FeatureSwitchLoaded: { [feature in FeatureName]?: boolean } = {}
+
 function settingKeyForName(featureName: FeatureName): string {
   return `Feature-Switch-${featureName}`
 }
 
 async function loadStoredValue(featureName: FeatureName) {
   if (isBrowserEnvironment && !IS_TEST_ENVIRONMENT) {
     const existing = await localforage.getItem<boolean | null>(settingKeyForName(featureName))
+    FeatureSwitchLoaded[featureName] = true
     if (existing != null) {
       FeatureSwitches[featureName] = existing
     }
+    return true
+  } else {
+    return true
   }
 }
 
 // Load stored settings
-fastForEach(AllFeatureNames, (name) => {
-  void loadStoredValue(name)
-})
+export async function loadFeatureSwitches(): Promise<void> {
+  if (IS_TEST_ENVIRONMENT) {
+    // in test environments, we actually don't want to load from localforage, ever
+    return
+  }
+  await Promise.all(
+    AllFeatureNames.map((name) => {
+      return loadStoredValue(name)
+    }),
+  )
+}
 
 export function isFeatureEnabled(featureName: FeatureName): boolean {
+  if (FeatureSwitchLoaded[featureName] !== true) {
+    if (!IS_TEST_ENVIRONMENT) {
+      // in test environments, we actually don't want to load from localforage, ever
+      throw new Error(`Reading FS before it was loaded! ${featureName}`)
+    }
+  }
   return FeatureSwitches[featureName] ?? false
 }