Option to customize the maximum truncated output

[shuding]

Clear and concise description of the problem

Currently Vitest uses process.stdout.columns || 80 as the limit of diff output. It would be great to have a way to customize that size, especially when you have a really long test snapshot.

- Expected   "something …
+ Received   "something …

Suggested solution

An outputTruncateLength option.

Alternative

No response

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[cuixiaorui]

please do you provide a demo for 'long test snapshot'

i need more context

[styfle]

@cuixiaorui Here's an example where the color of the svg was red but we expected blue. The output in the default macOS Terminal does not show the diff, instead it truncates.

import { it, expect } from 'vitest'

it('truncated', () => {
  const input = '<svgwidth="2000"height="4000"xmlns="http://www.w3.org/2000/svg"><pathd="M1010"/><circlecx="10"cy="10"r="2"fill="red"/></svg>'
  const output = '"<svgwidth=\\"2000\\"height=\\"4000\\"xmlns=\\"http://www.w3.org/2000/svg\\"><pathd=\\"M1010\\"/><circlecx=\\"10\\"cy=\\"10\\"r=\\"2\\"fill=\\"blue\\"/></svg>"'
  expect(input).toMatchInlineSnapshot(output)
})

[Aslemammad]

@styfle Let me check your demo and see if it's possible!

[jcalfee]

Where do I look when output is still truncated even though I specify vitest --outputTruncateLength 9999? (see #2671)

[nandastone]

If you're using testing-library and diffing DOM output please note it has its own internal print limit:

DEBUG_PRINT_LIMIT=100000 pnpm test

https://testing-library.com/docs/dom-testing-library/api-debugging/#automatic-logging