fix(expect): pass current equality testers to expect.extend asymmetric matchers

docs/guide/extending-matchers.md

@@ -150,6 +150,24 @@ If matcher was called on `resolved/rejected`, this value will contain the name o
 
 This is a utility function that allows you to compare two values. It will return `true` if values are equal, `false` otherwise. This function is used internally for almost every matcher. It supports objects with asymmetric matchers by default.
 
+## `customTesters`
+
+Equality testers to pass to `equals`, including ones registered with [`expect.addEqualityTesters`](/api/expect#expect-addequalitytesters).
+
+`equals` alone does not compare the contents of `Map` and `Set`. To get the same equality as `toEqual`, add `this.utils.iterableEquality`:
+
+```ts
+expect.extend({
+  toMyEqual(received: unknown, expected: unknown) {
+    const pass = this.equals(received, expected, [...this.customTesters, this.utils.iterableEquality])
+    return {
+      pass,
+      message: () => `expected ${this.utils.printReceived(received)} to equal ${this.utils.printExpected(expected)}`,
+    }
+  },
+})
+```
+
 ## `utils`
 
 This contains a set of utility functions that you can use to display messages.

packages/expect/src/jest-extend.ts

@@ -6,6 +6,7 @@ import type {
   MatchersObject,
   MatcherState,
   SyncExpectationResult,
+  Tester,
 } from './types'
 import { use, util } from 'chai'
 import { ASYMMETRIC_MATCHERS_OBJECT, JEST_MATCHERS_OBJECT } from './constants'
@@ -134,9 +135,10 @@ function JestExtendPlugin(
           super(sample, inverse)
         }
 
-        asymmetricMatch(other: unknown) {
+        asymmetricMatch(other: unknown, customTesters?: Array<Tester>) {
+          const context = this.getMatcherContext(expect)
           const { pass } = expectAssertion.call(
-            this.getMatcherContext(expect),
+            customTesters ? { ...context, customTesters } : context,
             other,
             ...this.sample,
           ) as SyncExpectationResult

test/unit/test/jest-expect.test.ts

@@ -226,6 +226,25 @@ describe('jest-expect', () => {
     expect([new Stock('x')]).toStrictEqual(expect.arrayContaining([new Stock('x')]))
   })
 
+  it('expect.extend asymmetric matchers and equality testers', () => {
+    // iterable equality testers
+    expect(new Set(['x'])).toEqual(expect.toBeOneOf([new Set(['x'])]))
+    expect(new Set()).not.toEqual(expect.toBeOneOf([new Set(['x'])]))
+
+    // `toStrictEqual` testers
+    class Stock {
+      constructor(public type: string) {}
+    }
+    expect(new Stock('x')).toEqual(expect.toBeOneOf([{ type: 'x' }]))
+    expect(new Stock('x')).not.toStrictEqual(expect.toBeOneOf([{ type: 'x' }]))
+    expect(new Stock('x')).toStrictEqual(expect.toBeOneOf([new Stock('x')]))
+
+    // non-asymmetric usage only sees registered testers
+    // TODO: https://github.com/vitest-dev/vitest/issues/11296
+    expect(new Set(['x'])).toBeOneOf([new Set(['x'])])
+    expect(new Set()).toBeOneOf([new Set(['x'])])
+  })
+
   // https://github.com/vitest-dev/vitest/issues/11071
   it('asymmetric matchers and toMatchObject equality', () => {
     expect([{ id: 1 }]).not.toMatchObject(expect.arrayContaining([{ id: 1, required: 'x' }]))