double invocation should be avoidable via canInitialize

Author: rlindner81

src/feature-toggles.js

@@ -1009,6 +1009,10 @@ class FeatureToggles {
     return await this.__initializePromise;
   }
 
+  get canInitialize() {
+    return !this.__initializePromise;
+  }
+
   // ========================================
   // END OF INITIALIZE SECTION
   // ========================================

test/integration-local/feature-toggles.integration.test.js

@@ -74,10 +74,14 @@ describe("local integration test", () => {
     };
 
     test("init throws for double invocation", async () => {
-      await toggles.initializeFeatures();
+      let initPromise;
+      expect(toggles.canInitialize).toBe(true);
+      initPromise = toggles.initializeFeatures();
+      expect(toggles.canInitialize).toBe(false);
       await expect(toggles.initializeFeatures()).rejects.toMatchInlineSnapshot(
         `[FeatureTogglesError: already initialized]`
       );
+      await initPromise;
     });
 
     test("init throws for non-existing filepaths", async () => {