fix(expect): correct behavior of toThrowError with empty string parameter (#6710)

Author: shulaoda

packages/expect/src/jest-expect.ts

@@ -643,7 +643,8 @@ export const JestChaiExpect: ChaiPlugin = (chai, utils) => {
         || typeof expected === 'undefined'
         || expected instanceof RegExp
       ) {
-        return this.throws(expected)
+        // Fixes the issue related to `chai` <https://github.com/vitest-dev/vitest/issues/6618>
+        return this.throws(expected === '' ? /^$/ : expected)
       }
 
       const obj = this._obj

test/core/test/jest-expect.test.ts

@@ -106,6 +106,13 @@ describe('jest-expect', () => {
       // eslint-disable-next-line no-throw-literal
       throw ''
     }).toThrow(/^$/)
+    expect(() => {
+      // eslint-disable-next-line no-throw-literal
+      throw ''
+    }).toThrow('')
+    expect(() => {
+      throw new Error('error')
+    }).not.toThrowError('')
     expect([1, 2, 3]).toHaveLength(3)
     expect('abc').toHaveLength(3)
     expect('').not.toHaveLength(5)