fix(browser): correctly print diff (#3627)

packages/utils/src/diff/diffLines.ts

@@ -184,7 +184,9 @@ export function diffLinesRaw(aLines: Array<string>,
   }
 
   // @ts-expect-error wrong bundling
-  diff.default.default(aLength, bLength, isCommon, foundSubsequence)
+  const diffSequences = diff.default.default || diff.default
+
+  diffSequences(aLength, bLength, isCommon, foundSubsequence)
 
   // After the last common subsequence, push remaining change items.
   for (; aIndex !== aLength; aIndex += 1)

packages/utils/src/diff/diffStrings.ts

@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-import * as diffSequences from 'diff-sequences'
+import * as diff from 'diff-sequences'
 import { DIFF_DELETE, DIFF_EQUAL, DIFF_INSERT, Diff } from './cleanupSemantic'
 
 function diffStrings(a: string, b: string): Array<Diff> {
@@ -32,7 +32,9 @@ function diffStrings(a: string, b: string): Array<Diff> {
   }
 
   // @ts-expect-error wrong bundling
-  diffSequences.default.default(a.length, b.length, isCommon, foundSubsequence)
+  const diffSequences = diff.default.default || diff.default
+
+  diffSequences(a.length, b.length, isCommon, foundSubsequence)
 
   // After the last common subsequence, push remaining change items.
   if (aIndex !== a.length)

test/browser/specs/runner.test.mjs

@@ -11,16 +11,26 @@ const { stderr, stdout } = await execa('npx', ['vitest', '--run', `--browser.nam
     CI: 'true',
     NO_COLOR: 'true',
   },
+  reject: false,
 })
 
 await test('tests are actually running', async () => {
   const browserResult = await readFile('./browser.json', 'utf-8')
   const browserResultJson = JSON.parse(browserResult)
 
-  assert.ok(browserResultJson.testResults.length === 7, 'Not all the tests have been run')
+  const passedTests = browserResultJson.testResults.filter(result => result.status === 'passed')
+  const failedTests = browserResultJson.testResults.filter(result => result.status === 'failed')
 
-  for (const result of browserResultJson.testResults)
-    assert.ok(result.status === 'passed', `${result.name} has failed`)
+  assert.ok(browserResultJson.testResults.length === 8, 'Not all the tests have been run')
+  assert.ok(passedTests.length === 7, 'Some tests failed')
+  assert.ok(failedTests.length === 1, 'Some tests have passed but should fail')
+
+  assert.doesNotMatch(stderr, /Unhandled Error/, 'doesn\'t have any unhandled errors')
+})
+
+await test('correctly prints error', () => {
+  assert.match(stderr, /expected 1 to be 2/, 'prints failing error')
+  assert.match(stderr, /- 2\s+\+ 1/, 'prints failing diff')
 })
 
 await test('logs are redirected to stdout', async () => {

test/browser/test/failing.test.ts

@@ -0,0 +1,5 @@
+import { expect, it } from 'vitest'
+
+it('correctly fails and prints a diff', () => {
+  expect(1).toBe(2)
+})