[Usage Collection/Cloud Provider] Fix isReady bug (elastic#97279)

src/plugins/kibana_usage_collection/server/collectors/cloud/cloud_provider_collector.test.ts

@@ -46,6 +46,11 @@ describe('registerCloudProviderUsageCollector', () => {
     expect(collector.isReady()).toBe(true);
   });
 
+  test('isReady() => true when cloud details have been retrieved but none have been found', () => {
+    cloudDetailsMock.mockReturnValueOnce(null);
+    expect(collector.isReady()).toBe(true);
+  });
+
   test('initiates CloudDetector.detectCloudDetails when called', () => {
     expect(detectCloudServiceMock).toHaveBeenCalledTimes(1);
   });

src/plugins/kibana_usage_collection/server/collectors/cloud/cloud_provider_collector.ts

@@ -23,7 +23,7 @@ export function registerCloudProviderUsageCollector(usageCollection: UsageCollec
 
   const collector = usageCollection.makeUsageCollector<Usage | undefined>({
     type: 'cloud_provider',
-    isReady: () => Boolean(cloudDetector.getCloudDetails()),
+    isReady: () => typeof cloudDetector.getCloudDetails() !== 'undefined',
     async fetch() {
       const details = cloudDetector.getCloudDetails();
       if (!details) {

src/plugins/kibana_usage_collection/server/collectors/cloud/detector/cloud_detector.test.ts

@@ -69,16 +69,16 @@ describe('CloudDetector', () => {
       expect(detector.getCloudDetails()).toEqual({ name: 'good-match' });
     });
 
-    it('returns undefined if none match', async () => {
+    it('returns null if none match', async () => {
       const services = ([cloudService1, cloudService2] as unknown) as CloudService[];
 
       const detector1 = new CloudDetector({ cloudServices: services });
       await detector1.detectCloudService();
-      expect(detector1.getCloudDetails()).toBeUndefined();
+      expect(detector1.getCloudDetails()).toBeNull();
 
       const detector2 = new CloudDetector({ cloudServices: [] });
       await detector2.detectCloudService();
-      expect(detector2.getCloudDetails()).toBeUndefined();
+      expect(detector2.getCloudDetails()).toBeNull();
     });
 
     // this is already tested above, but this just tests it explicitly
@@ -87,7 +87,7 @@ describe('CloudDetector', () => {
       const detector = new CloudDetector({ cloudServices: services });
 
       await detector.detectCloudService();
-      expect(detector.getCloudDetails()).toBeUndefined();
+      expect(detector.getCloudDetails()).toBeNull();
     });
   });
 });

src/plugins/kibana_usage_collection/server/collectors/cloud/detector/cloud_detector.ts

@@ -27,7 +27,7 @@ interface CloudDetectorOptions {
  */
 export class CloudDetector {
   private readonly cloudServices: CloudService[];
-  private cloudDetails?: CloudServiceResponseJson;
+  private cloudDetails?: CloudServiceResponseJson | null;
 
   constructor(options: CloudDetectorOptions = {}) {
     this.cloudServices =
@@ -70,7 +70,7 @@ export class CloudDetector {
       }
     }
 
-    // explicitly undefined rather than null so that it can be ignored in JSON
-    return undefined;
+    // explicitly null to differentiate from not having populated the field yet
+    return null;
   }
 }