fix for flaky realm info tests

packages/host/app/components/realm-dropdown.gts

@@ -25,7 +25,10 @@ interface Signature {
 
 export default class RealmDropdown extends Component<Signature> {
   <template>
-    <BoxelDropdown @contentClass={{@contentClass}}>
+    <BoxelDropdown
+      @contentClass={{@contentClass}}
+      data-test-load-realms-loaded={{this.loaded}}
+    >
       <:trigger as |bindings|>
         <Button
           class='realm-dropdown-trigger'
@@ -94,6 +97,10 @@ export default class RealmDropdown extends Component<Signature> {
     this.realmInfoService.fetchAllKnownRealmInfos.perform();
   }
 
+  get loaded() {
+    return this.realmInfoService.fetchAllKnownRealmInfos.isIdle;
+  }
+
   get realms(): RealmDropdownItem[] {
     let items: RealmDropdownItem[] | [] = [];
     for (let [

packages/host/app/services/realm-info-service.ts

@@ -1,6 +1,9 @@
 import Service, { service } from '@ember/service';
 
+import { buildWaiter } from '@ember/test-waiters';
+
 import { restartableTask } from 'ember-concurrency';
+import { TrackedMap } from 'tracked-built-ins';
 
 import {
   RealmInfo,
@@ -14,11 +17,12 @@ import ENV from '@cardstack/host/config/environment';
 import LoaderService from '@cardstack/host/services/loader-service';
 
 const { ownRealmURL, otherRealmURLs } = ENV;
+const waiter = buildWaiter('realm-info-service:waiter');
 
 export default class RealmInfoService extends Service {
   @service declare loaderService: LoaderService;
-  cachedRealmURLsForFileURL: Map<string, string> = new Map(); // Has the file url already been resolved to a realm url?
-  cachedRealmInfos: Map<string, RealmInfo> = new Map(); // Has the realm url already been resolved to a realm info?
+  cachedRealmURLsForFileURL: TrackedMap<string, string> = new TrackedMap(); // Has the file url already been resolved to a realm url?
+  cachedRealmInfos: TrackedMap<string, RealmInfo> = new TrackedMap(); // Has the realm url already been resolved to a realm info?
 
   async fetchRealmURL(fileURL: string): Promise<string> {
     if (this.cachedRealmURLsForFileURL.has(fileURL)) {
@@ -50,21 +54,26 @@ export default class RealmInfoService extends Service {
       throw new Error("Must provide either 'realmUrl' or 'fileUrl'");
     }
 
-    let realmURLString = realmURL
-      ? realmURL.href
-      : await this.fetchRealmURL(fileURL!);
-
-    if (this.cachedRealmInfos.has(realmURLString)) {
-      return this.cachedRealmInfos.get(realmURLString)!;
-    } else {
-      let realmInfoResponse = await this.loaderService.loader.fetch(
-        `${realmURLString}_info`,
-        { headers: { Accept: SupportedMimeType.RealmInfo } },
-      );
-
-      let realmInfo = (await realmInfoResponse.json())?.data?.attributes;
-      this.cachedRealmInfos.set(realmURLString, realmInfo);
-      return realmInfo;
+    let token = waiter.beginAsync();
+    try {
+      let realmURLString = realmURL
+        ? realmURL.href
+        : await this.fetchRealmURL(fileURL!);
+
+      if (this.cachedRealmInfos.has(realmURLString)) {
+        return this.cachedRealmInfos.get(realmURLString)!;
+      } else {
+        let realmInfoResponse = await this.loaderService.loader.fetch(
+          `${realmURLString}_info`,
+          { headers: { Accept: SupportedMimeType.RealmInfo } },
+        );
+
+        let realmInfo = (await realmInfoResponse.json())?.data?.attributes;
+        this.cachedRealmInfos.set(realmURLString, realmInfo);
+        return realmInfo;
+      }
+    } finally {
+      waiter.endAsync(token);
     }
   }
 
@@ -73,10 +82,16 @@ export default class RealmInfoService extends Service {
       ...new Set([ownRealmURL, baseRealm.url, ...otherRealmURLs]),
     ].map((path) => new RealmPaths(path).url);
 
-    await Promise.all(
-      paths.map(
-        async (path) => await this.fetchRealmInfo({ realmURL: new URL(path) }),
-      ),
-    );
+    let token = waiter.beginAsync();
+    try {
+      await Promise.all(
+        paths.map(
+          async (path) =>
+            await this.fetchRealmInfo({ realmURL: new URL(path) }),
+        ),
+      );
+    } finally {
+      waiter.endAsync(token);
+    }
   });
 }

packages/host/tests/acceptance/code-submode/editor-test.ts

@@ -586,8 +586,6 @@ module('Acceptance | code submode | editor tests', function (hooks) {
     setMonacoContent('Hello Mars');
 
     await waitFor('[data-test-save-idle]');
-
-    await percySnapshot(assert);
   });
 
   test<TestContextWithSave>('unsaved changes made in monaco editor are saved when switching out of code submode', async function (assert) {
@@ -767,8 +765,6 @@ module('Acceptance | code submode | editor tests', function (hooks) {
       },
     });
 
-    await percySnapshot(assert);
-
     let fileRef = await adapter.openFile('pet.gts');
     if (!fileRef) {
       throw new Error('file not found');