fix(utils): Produce valid snapshot names (#5724)

packages/utils/package.json

@@ -63,7 +63,7 @@
   "dependencies": {
     "diff-sequences": "^29.6.3",
     "estree-walker": "^3.0.3",
-    "loupe": "^3.1.0",
+    "loupe": "^3.1.1",
     "pretty-format": "^29.7.0"
   },
   "devDependencies": {

test/core/test/utils.spec.ts

@@ -1,5 +1,5 @@
 import { beforeAll, describe, expect, test } from 'vitest'
-import { assertTypes, deepClone, objectAttr, toArray } from '@vitest/utils'
+import { assertTypes, deepClone, objDisplay, objectAttr, toArray } from '@vitest/utils'
 import { deepMerge, resetModules } from '../../../packages/vitest/src/utils'
 import { deepMergeSnapshot } from '../../../packages/snapshot/src/port/utils'
 import type { EncodedSourceMap } from '../../../packages/vite-node/src/types'
@@ -271,3 +271,17 @@ describe('objectAttr', () => {
     expect(objectAttr(value, path)).toEqual(expected)
   })
 })
+
+describe('objDisplay', () => {
+  test.each`
+  value | expected
+  ${'a'.repeat(100)} | ${`'${'a'.repeat(37)}…'`}
+  ${'🐱'.repeat(100)} | ${`'${'🐱'.repeat(18)}…'`}
+  ${`a${'🐱'.repeat(100)}…`} | ${`'a${'🐱'.repeat(18)}…'`}
+  `('Do not truncate strings anywhere but produce valid unicode strings for $value', ({ value, expected }) => {
+    // encodeURI can be used to detect invalid strings including invalid code-points
+    // note: our code should not split surrogate pairs, but may split graphemes
+    expect(() => encodeURI(objDisplay(value))).not.toThrow()
+    expect(objDisplay(value)).toEqual(expected)
+  })
+})