From 97abcb984b0ee76d7c306fc21c9881962f35a0b2 Mon Sep 17 00:00:00 2001
From: Vladimir Sheremet <sheremet.va@icloud.com>
Date: Wed, 29 Dec 2021 19:34:58 +0300
Subject: [PATCH] fix: incorrect behaviour of toBeDefined with not flag

---
 packages/vitest/src/integrations/chai/jest-expect.ts | 6 ++++++
 test/core/test/jest-expect.test.ts                   | 3 +++
 2 files changed, 9 insertions(+)

diff --git a/packages/vitest/src/integrations/chai/jest-expect.ts b/packages/vitest/src/integrations/chai/jest-expect.ts
index e42f3182253e..66e2267fb32b 100644
--- a/packages/vitest/src/integrations/chai/jest-expect.ts
+++ b/packages/vitest/src/integrations/chai/jest-expect.ts
@@ -194,6 +194,12 @@ export const JestChaiExpect: ChaiPlugin = (chai, utils) => {
     return this.be.null
   })
   def('toBeDefined', function() {
+    const negate = utils.flag(this, 'negate')
+    utils.flag(this, 'negate', false)
+
+    if (negate)
+      return this.be.undefined
+
     return this.not.be.undefined
   })
   def('toBeInstanceOf', function(obj: any) {
diff --git a/test/core/test/jest-expect.test.ts b/test/core/test/jest-expect.test.ts
index ad487c2989f4..f5080ccec6af 100644
--- a/test/core/test/jest-expect.test.ts
+++ b/test/core/test/jest-expect.test.ts
@@ -6,7 +6,10 @@ describe('jest-expect', () => {
   it('basic', () => {
     expect(1).toBe(1)
     expect(null).toBeNull()
+    expect(1).not.toBeNull()
     expect(null).toBeDefined()
+    expect(undefined).not.toBeDefined()
+    expect(undefined).toBeUndefined()
     expect(null).not.toBeUndefined()
     expect([]).toBeTruthy()
     expect(0).toBeFalsy()