[Feature]: Both --update-snapshots and fail on changes

[SrBrahma]

🚀 Feature Request

https://discord.com/channels/807756831384403968/1222482350798143488/1222482350798143488

On screenshot changes, I want my CI to fail.

When it fails, a manual job will be available to commit the screenshot changes so that a new CI run will be made, and it shouldn't fail.

I don't want to use --update-snapshots as it doesn't create the diff images and it doesn't fail.

Example

No response

Motivation

I want to integrate Playwright with my CI workflow.

In the meantime, I will make a wrapping code that merges the changed images and the current images.

[SrBrahma]

I think we could actually change this to be:

updateSnapshots: 'all' doesn't create expected and diff.

I have the following in my CI to detect screenshot changes:

- >
  if ! git diff --exit-code || [ -n "$(git ls-files --others --exclude-standard)" ]; then
    echo "🚨 There are screenshot changes! Check them out in the Artifacts and run the 'playwright-accept-changes' job if you agree with them."
    echo "Listing names of changed files:"
    git diff --name-only
    echo "Listing untracked files:"
    git ls-files --others --exclude-standard
    exit 1
  else
    echo "✅ No Playwright screenshot changes detected."
  fi