[DRAFT] Improve the host test performance

.github/workflows/ci-host.yaml

@@ -31,8 +31,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        shardIndex: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]
-        shardTotal: [16]
+        shardIndex: [1, 2, 3, 4, 5, 6, 7, 8]
+        shardTotal: [8]
     concurrency:
       group: boxel-host-test${{ github.head_ref || github.run_id }}-shard${{ matrix.shardIndex }}
       cancel-in-progress: true

packages/host/app/lib/browser-queue.ts

@@ -77,9 +77,13 @@ export class BrowserQueue implements QueuePublisher, QueueRunner {
     return job;
   }
 
-  private debouncedDrainJobs = debounce(() => {
-    this.drainJobs();
-  }, 250);
+  private debouncedDrainJobs = debounce(
+    () => {
+      this.drainJobs();
+    },
+    1,
+    { leading: true },
+  );
 
   private async drainJobs() {
     await this.flush();

packages/host/app/lib/sqlite-adapter.ts

@@ -200,6 +200,20 @@ export default class SQLiteAdapter implements DBAdapter {
     return alias;
   }
 
+  async deleteSnapshot(snapshotName: string) {
+    this.assertNotClosed();
+    await this.started;
+    let snapshotInfo = this.snapshotInfos.get(snapshotName);
+    if (!snapshotInfo) {
+      throw new Error(`Unknown snapshot database '${snapshotName}'`);
+    }
+    await this.sqlite('exec', {
+      dbId: this.dbId,
+      sql: `DETACH DATABASE ${snapshotName};`,
+    });
+    this.snapshotInfos.delete(snapshotName);
+  }
+
   async importSnapshot(snapshotName: string) {
     this.assertNotClosed();
     await this.started;

packages/host/app/services/loader-service.ts

@@ -5,6 +5,7 @@ import Service, { service } from '@ember/service';
 import { tracked } from '@glimmer/tracking';
 
 import type { FetcherMiddlewareHandler } from '@cardstack/runtime-common';
+import { baseRealm } from '@cardstack/runtime-common';
 import {
   fetcher,
   maybeHandleScopedCSSRequest,
@@ -22,6 +23,7 @@ import type NetworkService from './network';
 import type RealmService from './realm';
 import type RealmInfoService from './realm-info-service';
 import type ResetService from './reset';
+import { isTesting } from '@embroider/macros';
 
 const log = logger('loader-service');
 
@@ -68,7 +70,15 @@ export default class LoaderService extends Service {
       // by default we keep the fetch cache so we can take advantage of HTTP
       // caching when rebuilding the loader state
       if (this.loader) {
-        this.loader = Loader.cloneLoader(this.loader);
+        // If we're testing, we can keep the base realm modules cached to speed
+        // up tests
+        if (isTesting()) {
+          this.loader = Loader.cloneLoader(this.loader, {
+            includeEvaluatedModules: `${baseRealm.url}.*`,
+          });
+        } else {
+          this.loader = Loader.cloneLoader(this.loader);
+        }
       } else {
         this.loader = this.makeInstance();
       }

packages/host/tests/acceptance/ai-assistant-test.gts

@@ -119,7 +119,7 @@ function modelNameFor(llmId: string): string {
 
 module('Acceptance | AI Assistant tests', function (hooks) {
   setupApplicationTest(hooks);
-  setupLocalIndexing(hooks);
+
   setupOnSave(hooks);
 
   let mockMatrixUtils = setupMockMatrix(hooks, {

packages/host/tests/acceptance/basic-test.gts

@@ -16,7 +16,6 @@ import { setupApplicationTest } from '../helpers/setup';
 
 module('Acceptance | basic tests', function (hooks) {
   setupApplicationTest(hooks);
-  setupLocalIndexing(hooks);
 
   let mockMatrixUtils = setupMockMatrix(hooks, {
     loggedInAs: '@testuser:localhost',

packages/host/tests/acceptance/catalog-app-test.gts

@@ -163,7 +163,7 @@ const cardWithUnrecognisedImports = `
 
 module('Acceptance | Catalog | catalog app tests', function (hooks) {
   setupApplicationTest(hooks);
-  setupLocalIndexing(hooks);
+
   setupOnSave(hooks);
 
   let mockMatrixUtils = setupMockMatrix(hooks, {
@@ -792,7 +792,7 @@ module('Acceptance | Catalog | catalog app tests', function (hooks) {
     snapshot.get();
   });
 
-/**
+  /**
    * Selects a tab by name within the catalog app
    */
   async function selectTab(tabName: string) {

packages/host/tests/acceptance/code-patches-test.gts

@@ -62,7 +62,7 @@ export class TestCard extends CardDef {
 
 module('Acceptance | Code patches tests', function (hooks) {
   setupApplicationTest(hooks);
-  setupLocalIndexing(hooks);
+
   setupOnSave(hooks);
 
   let mockMatrixUtils = setupMockMatrix(hooks, {