Apply transforms to handlers built via toHandlers

[michael-wolfenden]

Is is possible to apply addition transforms to handlers built via toHandlers, for example to introduce a delay to each handler.

[kettanaito]

Hey, @michael-wolfenden.

No, currently that is not possible. Can you tell me more about your use case? What is the ideal API in your opinion to customize .toHandlers() behavior?

[michael-wolfenden]

What if you could pass your own custom response method as shown in the example below:
https://mswjs.io/docs/api/response#custom-response-composition

[kettanaito]

You can define a delay that affects all generated handlers by creating a passthrough handler:

const handlers = [
  rest.all('/user/*', async (req, res, ctx) => {
    // This will delay any requests to "/user" by 1000ms
    // and then perform them as-is, falling further to the
    // generated handlers below. 
    await new Promise(resolve => setTimeout(resolve, 1000))
    return req.passthrough()
  }),
  ...db.user.toHandlers('/user'),
]

[kettanaito]

I'm thinking that it'd more flexible to turn the intention around: have something like .toTransformers() that you can supply to any res() call:

rest.get('/route', (req, res, ctx) => {
  return res(...db.user.toTransformers())
})

The issue here is that DB would lose direct access to the request info like parameters, creating a surface for user errors and complicating the call signature since now you need to forward those parameters manually.

[michael-wolfenden]

Thanks @kettanaito, I'll give the passthrough handler a try