From 905ec05abfae5a2beea481ba107c27e3c4ac5ad6 Mon Sep 17 00:00:00 2001
From: Vladimir <sleuths.slews0s@icloud.com>
Date: Tue, 11 Apr 2023 09:23:39 +0200
Subject: [PATCH] fix: allow augmenting jest namespace for custom assertions
 (#3169)

---
 packages/vitest/src/types/global.ts |  3 ++-
 test/core/test/jest-expect.test.ts  | 15 +++++++++++++++
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/packages/vitest/src/types/global.ts b/packages/vitest/src/types/global.ts
index 7caa840b565d..224984c54490 100644
--- a/packages/vitest/src/types/global.ts
+++ b/packages/vitest/src/types/global.ts
@@ -44,7 +44,8 @@ declare global {
   // support augmenting jest.Matchers by other libraries
   namespace jest {
 
-    interface Matchers<_R, _T = {}> {}
+    // eslint-disable-next-line unused-imports/no-unused-vars
+    interface Matchers<R, T = {}> {}
   }
 
   namespace Vi {
diff --git a/test/core/test/jest-expect.test.ts b/test/core/test/jest-expect.test.ts
index 5a40747b5b7b..75356b3798a2 100644
--- a/test/core/test/jest-expect.test.ts
+++ b/test/core/test/jest-expect.test.ts
@@ -12,7 +12,14 @@ interface CustomMatchers<R = unknown> {
   toBeTestedSync(): R
   toBeTestedPromise(): R
 }
+
 declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toBeJestCompatible(): R
+    }
+  }
+
   namespace Vi {
     interface JestAssertion extends CustomMatchers {}
     interface AsymmetricMatchersContaining extends CustomMatchers {}
@@ -182,6 +189,12 @@ describe('jest-expect', () => {
           message: () => 'toBeTestedPromise',
         })
       },
+      toBeJestCompatible() {
+        return {
+          pass: true,
+          message: () => '',
+        }
+      },
     })
 
     expect(5).toBeDividedBy(5)
@@ -195,6 +208,8 @@ describe('jest-expect', () => {
     expect(() => expect(null).toBeTestedSync()).toThrowError('toBeTestedSync')
     await expect(async () => await expect(null).toBeTestedAsync()).rejects.toThrowError('toBeTestedAsync')
     await expect(async () => await expect(null).toBeTestedPromise()).rejects.toThrowError('toBeTestedPromise')
+
+    expect(expect).toBeJestCompatible()
   })
 
   it('object', () => {