feat: allow forwarding of requests with ctx.forward

[mcky]

As discussed in #234 and #676 (Add "ctx.forward" for forwarding (bypassing) requests) this adds a ctx.forward() method.

The new API looks like

rest.get('/user', (req, res, ctx) => {
  if (anything) {
    return res(ctx.forward())
  }

  return res(ctx.text('mocked'))
})

It differs slightly to the suggestion in #676 as it wraps the forward call in res() - if that's a deal breaker I can try to figure out how to implement it as per the issue

The behaviour is exactly the same as a x-msw-bypass header or returning undefined, just without the warnings.

Happy with any and all feedback - for now I've hacked in a x-msw-bypass into my own test-suite just to silence the undefined warnings 😅

Todo:

• Update documentation

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[kettanaito]

Hey, @mcky. Thank you so much for your work on this feature. I've decided to go with #1204.

[mcky]

Hey, @mcky. Thank you so much for your work on this feature. I've decided to go with #1204.

Glad to see a solution is in either way!

[kettanaito]

Released: v0.40.0 🎉

This has been released in v0.40.0!

• 📄 Release notes
• 📦 npm package

Make sure to always update to the latest version (npm i msw@latest) to get the newest features and bug fixes.

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