fix: don't escape "\" in diff view (#2430)

Author: poyoho

packages/vitest/src/integrations/chai/jest-matcher-utils.ts

@@ -109,6 +109,7 @@ export function stringify(object: unknown, maxDepth = 10, options?: PrettyFormat
  try {
  result = prettyFormat(object, {
  maxDepth,
+ escapeString: false,
  // min: true,
  plugins: PLUGINS,
  ...options,
@@ -118,6 +119,7 @@ export function stringify(object: unknown, maxDepth = 10, options?: PrettyFormat
  result = prettyFormat(object, {
  callToJSON: false,
  maxDepth,
+ escapeString: false,
  // min: true,
  plugins: PLUGINS,
  ...options,

test/core/test/basic.test.ts

@@ -58,3 +58,8 @@ it.fails('deprecated done callback', (done) => {
  // @ts-expect-error deprecated done callback is not typed
  done()
 })
+
+test('escaping', () => {
+ expect(['\\123']).toEqual(['\\123'])
+ expect('\\123').toEqual('\\123')
+})