fix: copy custom asymmetric matchers to local expect (#4405)

Author: hi-ogawa

packages/expect/src/constants.ts

@@ -1,3 +1,4 @@
 export const MATCHERS_OBJECT = Symbol.for('matchers-object')
 export const JEST_MATCHERS_OBJECT = Symbol.for('$$jest-matchers-object')
 export const GLOBAL_EXPECT = Symbol.for('expect-global')
+export const ASYMMETRIC_MATCHERS_OBJECT = Symbol.for('asymmetric-matchers-object')

packages/expect/src/jest-extend.ts

@@ -6,7 +6,7 @@ import type {
   MatchersObject,
   SyncExpectationResult,
 } from './types'
-import { JEST_MATCHERS_OBJECT } from './constants'
+import { ASYMMETRIC_MATCHERS_OBJECT, JEST_MATCHERS_OBJECT } from './constants'
 import { AsymmetricMatcher } from './jest-asymmetric-matchers'
 import { getState } from './state'
 
@@ -108,10 +108,12 @@ function JestExtendPlugin(expect: ExpectStatic, matchers: MatchersObject): ChaiP
         }
       }
 
+      const customMatcher = (...sample: [unknown, ...unknown[]]) => new CustomMatcher(false, ...sample)
+
       Object.defineProperty(expect, expectAssertionName, {
         configurable: true,
         enumerable: true,
-        value: (...sample: [unknown, ...unknown[]]) => new CustomMatcher(false, ...sample),
+        value: customMatcher,
         writable: true,
       })
 
@@ -121,6 +123,15 @@ function JestExtendPlugin(expect: ExpectStatic, matchers: MatchersObject): ChaiP
         value: (...sample: [unknown, ...unknown[]]) => new CustomMatcher(true, ...sample),
         writable: true,
       })
+
+      // keep track of asymmetric matchers on global so that it can be copied over to local context's `expect`.
+      // note that the negated variant is automatically shared since it's assigned on the single `expect.not` object.
+      Object.defineProperty(((globalThis as any)[ASYMMETRIC_MATCHERS_OBJECT]), expectAssertionName, {
+        configurable: true,
+        enumerable: true,
+        value: customMatcher,
+        writable: true,
+      })
     })
   }
 }

packages/expect/src/state.ts

@@ -1,9 +1,10 @@
 import type { ExpectStatic, MatcherState } from './types'
-import { GLOBAL_EXPECT, JEST_MATCHERS_OBJECT, MATCHERS_OBJECT } from './constants'
+import { ASYMMETRIC_MATCHERS_OBJECT, GLOBAL_EXPECT, JEST_MATCHERS_OBJECT, MATCHERS_OBJECT } from './constants'
 
 if (!Object.prototype.hasOwnProperty.call(globalThis, MATCHERS_OBJECT)) {
   const globalState = new WeakMap<ExpectStatic, MatcherState>()
   const matchers = Object.create(null)
+  const assymetricMatchers = Object.create(null)
   Object.defineProperty(globalThis, MATCHERS_OBJECT, {
     get: () => globalState,
   })
@@ -14,6 +15,9 @@ if (!Object.prototype.hasOwnProperty.call(globalThis, MATCHERS_OBJECT)) {
       matchers,
     }),
   })
+  Object.defineProperty(globalThis, ASYMMETRIC_MATCHERS_OBJECT, {
+    get: () => assymetricMatchers,
+  })
 }
 
 export function getState<State extends MatcherState = MatcherState>(expect: ExpectStatic): State {

packages/vitest/src/integrations/chai/index.ts

@@ -4,7 +4,7 @@ import * as chai from 'chai'
 import './setup'
 import type { TaskPopulated, Test } from '@vitest/runner'
 import { getCurrentTest } from '@vitest/runner'
-import { GLOBAL_EXPECT, getState, setState } from '@vitest/expect'
+import { ASYMMETRIC_MATCHERS_OBJECT, GLOBAL_EXPECT, getState, setState } from '@vitest/expect'
 import type { Assertion, ExpectStatic } from '@vitest/expect'
 import type { MatcherState } from '../../types/chai'
 import { getFullName } from '../../utils/tasks'
@@ -23,6 +23,7 @@ export function createExpect(test?: TaskPopulated) {
       return assert
   }) as ExpectStatic
   Object.assign(expect, chai.expect)
+  Object.assign(expect, (globalThis as any)[ASYMMETRIC_MATCHERS_OBJECT])
 
   expect.getState = () => getState<MatcherState>(expect)
   expect.setState = state => setState(state as Partial<MatcherState>, expect)

test/core/test/local-context.test.ts

@@ -36,3 +36,42 @@ describe('context expect', () => {
     expect(localExpect.getState().snapshotState).toBeDefined()
   })
 })
+
+describe('custom matcher are inherited by local context', () => {
+  expect.extend({
+    toEqual_testCustom(received, expected) {
+      return {
+        pass: received === expected,
+        message: () => `test`,
+      }
+    },
+  })
+
+  it('basic', ({ expect: localExpect }) => {
+    // as assertion
+    expect(expect('test')).toHaveProperty('toEqual_testCustom')
+    expect(expect.soft('test')).toHaveProperty('toEqual_testCustom')
+    expect(localExpect('test')).toHaveProperty('toEqual_testCustom')
+    expect(localExpect.soft('test')).toHaveProperty('toEqual_testCustom')
+
+    // as asymmetric matcher
+    expect(expect).toHaveProperty('toEqual_testCustom')
+    expect(expect.not).toHaveProperty('toEqual_testCustom')
+    expect(localExpect).toHaveProperty('toEqual_testCustom')
+    expect(localExpect.not).toHaveProperty('toEqual_testCustom');
+
+    (expect(0) as any).toEqual_testCustom(0);
+    (expect(0) as any).not.toEqual_testCustom(1);
+    (localExpect(0) as any).toEqual_testCustom(0);
+    (localExpect(0) as any).not.toEqual_testCustom(1)
+
+    expect(0).toEqual((expect as any).toEqual_testCustom(0))
+    localExpect(0).toEqual((localExpect as any).toEqual_testCustom(0))
+    expect(0).toEqual((expect.not as any).toEqual_testCustom(1))
+    localExpect(0).toEqual((localExpect.not as any).toEqual_testCustom(1))
+
+    // asymmetric matcher function is identical
+    expect((expect as any).toEqual_testCustom).toBe((localExpect as any).toEqual_testCustom)
+    expect((expect.not as any).toEqual_testCustom).toBe((localExpect.not as any).toEqual_testCustom)
+  })
+})