fix(expect): fix toEqual and toMatchObject with circular references (#5535)

Author: hi-ogawa

packages/expect/src/jest-expect.ts

@@ -164,17 +164,18 @@ export const JestChaiExpect: ChaiPlugin = (chai, utils) => {
     const pass = jestEquals(actual, expected, [...customTesters, iterableEquality, subsetEquality])
     const isNot = utils.flag(this, 'negate') as boolean
     const { subset: actualSubset, stripped } = getObjectSubset(actual, expected)
-    const msg = utils.getMessage(
-      this,
-      [
-        pass,
-        'expected #{this} to match object #{exp}',
-        'expected #{this} to not match object #{exp}',
-        expected,
-        actualSubset,
-      ],
-    )
     if ((pass && isNot) || (!pass && !isNot)) {
+      const msg = utils.getMessage(
+        this,
+        [
+          pass,
+          'expected #{this} to match object #{exp}',
+          'expected #{this} to not match object #{exp}',
+          expected,
+          actualSubset,
+          false,
+        ],
+      )
       const message = stripped === 0 ? msg : `${msg}\n(${stripped} matching ${stripped === 1 ? 'property' : 'properties'} omitted from actual)`
       throw new AssertionError(message, { showDiff: true, expected, actual: actualSubset })
     }

packages/expect/src/jest-utils.ts

@@ -334,7 +334,7 @@ export function iterableEquality(a: any, b: any, customTesters: Array<Tester> =
     return iterableEquality(
       a,
       b,
-      [...filteredCustomTesters],
+      [...customTesters],
       [...aStack],
       [...bStack],
     )
@@ -452,7 +452,7 @@ export function subsetEquality(object: unknown, subset: unknown, customTesters:
           return undefined
 
         return Object.keys(subset).every((key) => {
-          if (isObjectWithKeys(subset[key])) {
+          if (typeof subset[key] === 'object') {
             if (seenReferences.has(subset[key]))
               return equals(object[key], subset[key], filteredCustomTesters)
 

test/core/test/expect-circular.test.ts

@@ -0,0 +1,60 @@
+import { describe, expect, test } from 'vitest'
+
+describe('circular equality', () => {
+  test('object, set, map', () => {
+    // https://github.com/vitest-dev/vitest/issues/5533
+    function gen() {
+      const obj = {
+        a: new Set<any>(),
+        b: new Map<any, any>(),
+      }
+      obj.a.add(obj)
+      obj.b.set('k', obj)
+      return obj
+    }
+    expect(gen()).toEqual(gen())
+    expect(gen()).toMatchObject(gen())
+  })
+
+  test('object, set', () => {
+    function gen() {
+      const obj = {
+        a: new Set<any>(),
+        b: new Set<any>(),
+      }
+      obj.a.add(obj)
+      obj.b.add(obj)
+      return obj
+    }
+    expect(gen()).toEqual(gen())
+    expect(gen()).toMatchObject(gen())
+  })
+
+  test('array, set', () => {
+    function gen() {
+      const obj = [new Set<any>(), new Set<any>()]
+      obj[0].add(obj)
+      obj[1].add(obj)
+      return obj
+    }
+    expect(gen()).toEqual(gen())
+    expect(gen()).toMatchObject(gen())
+  })
+
+  test('object, array', () => {
+    // https://github.com/jestjs/jest/issues/14734
+    function gen() {
+      const a: any = {
+        v: 1,
+      }
+      const c1: any = {
+        ref: [],
+      }
+      c1.ref.push(c1)
+      a.ref = c1
+      return a
+    }
+    expect(gen()).toEqual(gen())
+    expect(gen()).toMatchObject(gen())
+  })
+})