Workaround a node >=12.5.0 bug that causes the process not to exit after tests have completed and cancerous memory growth

CHANGELOG.md

@@ -34,6 +34,7 @@
 - `[jest-snapshots]` Fix test retries that contain snapshots ([#8629](https://github.com/facebook/jest/pull/8629))
 - `[jest-mock]` Fix incorrect assignments when restoring mocks in instances where they originally didn't exist ([#8631](https://github.com/facebook/jest/pull/8631))
 - `[expect]` Fix stack overflow when matching objects with circular references ([#8687](https://github.com/facebook/jest/pull/8687))
+- `[jest-haste-map]` Workaround a node >=12.5.0 bug that causes the process not to exit after tests have completed and cancerous memory growth  ([#8787](https://github.com/facebook/jest/pull/8787))
 
 ### Chore & Maintenance
 

packages/jest-haste-map/src/index.ts

@@ -642,7 +642,7 @@ class HasteMap extends EventEmitter {
       .then(workerReply, workerError);
   }
 
-  private async _buildHasteMap(data: {
+  private _buildHasteMap(data: {
     removedFiles: FileData;
     changedFiles?: FileData;
     hasteMap: InternalHasteMap;
@@ -687,16 +687,18 @@ class HasteMap extends EventEmitter {
       }
     }
 
-    try {
-      await Promise.all(promises);
-      this._cleanup();
-      hasteMap.map = map;
-      hasteMap.mocks = mocks;
-      return hasteMap;
-    } catch (error) {
-      this._cleanup();
-      throw error;
-    }
+    return Promise.all(promises).then(
+      () => {
+        this._cleanup();
+        hasteMap.map = map;
+        hasteMap.mocks = mocks;
+        return hasteMap;
+      },
+      error => {
+        this._cleanup();
+        throw error;
+      },
+    );
   }
 
   private _cleanup() {