fix: `bigint` cause error (#15702)

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## main
 
+### Fixes
+
+- `[expect]` Fix `bigint` error ([#15702](https://github.com/jestjs/jest/pull/15702))
+
 ## 30.0.4
 
 ### Features

packages/expect/src/__tests__/toThrowMatchers.test.ts

@@ -328,6 +328,15 @@ describe('toThrow', () => {
         });
       });
 
+      test('isNot false, cause is bigint', () => {
+        jestExpect(() => {
+          throw new Error('Message', {cause: 0n});
+        }).toThrow({
+          cause: 0n,
+          message: 'Message',
+        });
+      });
+
       test('isNot false, cause is object', () => {
         jestExpect(() => {
           throw new Error('Message', {

packages/expect/src/toThrowMatchers.ts

@@ -486,7 +486,10 @@ function createMessageAndCause(error: Error) {
         if (seen.has(value)) return;
         seen.add(value); // stop circular references
       }
-      return value === undefined ? String(undefined) : value;
+      if (typeof value === 'bigint' || value === undefined) {
+        return String(value);
+      }
+      return value;
     });
   }