fix: assertion diff message now handle non writable property correctly

packages/runner/src/utils/error.ts

@@ -97,8 +97,8 @@ export function processError(err: any, options: DiffOptions = {}) {
   if (err.name)
     err.nameStr = String(err.name)
 
-  const clonedActual = deepClone(err.actual)
-  const clonedExpected = deepClone(err.expected)
+  const clonedActual = deepClone(err.actual, { forceWritable: true })
+  const clonedExpected = deepClone(err.expected, { forceWritable: true })
 
   const { replacedActual, replacedExpected } = replaceAsymmetricMatcher(clonedActual, clonedExpected)
 

packages/utils/src/helpers.ts

@@ -1,5 +1,9 @@
 import type { Arrayable, Nullable } from './types'
 
+interface CloneOptions {
+  forceWritable?: boolean
+}
+
 export function notNullish<T>(v: T | null | undefined): v is NonNullable<T> {
   return v != null
 }
@@ -72,20 +76,28 @@ export function getOwnProperties(obj: any) {
   return Array.from(ownProps)
 }
 
-export function deepClone<T>(val: T): T {
+const defaultCloneOptions: CloneOptions = { forceWritable: false }
+
+export function deepClone<T>(
+  val: T,
+  options: CloneOptions = defaultCloneOptions,
+): T {
   const seen = new WeakMap()
-  return clone(val, seen)
+  return clone(val, seen, options)
 }
 
-export function clone<T>(val: T, seen: WeakMap<any, any>): T {
+export function clone<T>(
+  val: T,
+  seen: WeakMap<any, any>,
+  options: CloneOptions = defaultCloneOptions,
+): T {
   let k: any, out: any
   if (seen.has(val))
     return seen.get(val)
   if (Array.isArray(val)) {
-    out = Array(k = val.length)
+    out = Array((k = val.length))
     seen.set(val, out)
-    while (k--)
-      out[k] = clone(val[k], seen)
+    while (k--) out[k] = clone(val[k], seen)
     return out as any
   }
 
@@ -110,6 +122,7 @@ export function clone<T>(val: T, seen: WeakMap<any, any>): T {
       else {
         Object.defineProperty(out, k, {
           ...descriptor,
+          writable: options.forceWritable ? true : descriptor.writable,
           value: cloned,
         })
       }

test/core/test/error.test.ts

@@ -0,0 +1,24 @@
+import { processError } from '@vitest/runner/utils'
+import { expect, test } from 'vitest'
+
+test('Can correctly process error where actual and expected contains non writable properties', () => {
+  const actual = {}
+  const expected = {}
+  Object.defineProperty(actual, 'root', {
+    value: { foo: 'bar' },
+    writable: false,
+    enumerable: true,
+  })
+  Object.defineProperty(expected, 'root', {
+    value: { foo: 'NOT BAR' },
+    writable: false,
+    enumerable: true,
+  })
+
+  const err = {
+    actual,
+    expected,
+  }
+
+  expect(() => processError(err)).not.toThrow(TypeError)
+})

test/core/test/utils.spec.ts

@@ -142,7 +142,20 @@ describe('deepClone', () => {
       value: 1,
       writable: false,
     })
+    Object.defineProperty(objB, 'writableValue', {
+      configurable: false,
+      enumerable: false,
+      value: 1,
+      writable: true,
+    })
     expect(deepClone(objB).value).toEqual(objB.value)
+    expect(Object.getOwnPropertyDescriptor(deepClone(objB), 'value')?.writable).toEqual(false)
+    expect(
+      Object.getOwnPropertyDescriptor(deepClone(objB), 'writableValue')?.writable,
+    ).toEqual(true)
+    expect(
+      Object.getOwnPropertyDescriptor(deepClone(objB, { forceWritable: true }), 'value')?.writable,
+    ).toEqual(true)
     const objC = Object.create(objB)
     expect(deepClone(objC).value).toEqual(objC.value)
     const objD: any = { name: 'd', ref: null }