fix(jest-circus): prevent crash when asyncError is undefined for non-Error throws

packages/jest-circus/src/__tests__/asyncError.test.ts

@@ -0,0 +1,23 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+describe('async error handling', () => {
+  it('does not crash when asyncError is undefined and a plain object is thrown', done => {
+    const {test} = require('../');
+
+    test('inner test', (innerDone: any) => {
+      // simulate async error path (where asyncError can be undefined)
+      Promise.resolve().then(() => {
+        throw Object.assign(new Error('Forbidden'), {status: 403});
+      });
+
+      innerDone();
+    });
+
+    done();
+  });
+});

packages/jest-circus/src/formatNodeAssertErrors.ts

@@ -52,12 +52,17 @@ const formatNodeAssertErrors = (
           error = asyncError;
         } else if (originalError.stack) {
           error = originalError;
-        } else {
+        } else if (asyncError) {
           error = asyncError;
 
           error.message =
             originalError.message ||
             `thrown: ${prettyFormat(originalError, {maxDepth: 3})}`;
+        } else {
+          error = new Error(
+            originalError.message ||
+              `thrown: ${prettyFormat(originalError, {maxDepth: 3})}`,
+          );
         }
       } else {
         error = errors;

packages/jest-circus/src/utils.ts

@@ -433,9 +433,12 @@ const _getError = (
     return error;
   }
 
-  asyncError.message = `thrown: ${prettyFormat(error, {maxDepth: 3})}`;
+  if (asyncError) {
+    asyncError.message = `thrown: ${prettyFormat(error, {maxDepth: 3})}`;
+    return asyncError;
+  }
 
-  return asyncError;
+  return new Error(`thrown: ${prettyFormat(error, {maxDepth: 3})}`);
 };
 
 const getErrorStack = (error: Error): string =>

packages/jest-types/src/Circus.ts

@@ -273,7 +273,9 @@ export type DescribeBlock = {
   tests: Array<TestEntry>;
 };
 
-export type TestError = Exception | [Exception | undefined, Exception]; // the error from the test, as well as a backup error for async
+export type TestError =
+  | Exception
+  | [Exception | undefined, Exception | undefined]; // the error from the test, as well as a backup error for async
 
 export type TestEntry = {
   type: 'test';