[8.x] Display unexpected validation errors when asserting status

[jessarcher]

This PR expands on #38025 to also show any unexpected validation errors that occurred when asserting a status code other than 422.

Currently the only way to see the validation errors is by dumping the response, running the test again, and then removing the dump. With this PR, the unexpected validation errors will be displayed straight away.

If the response being asserted against is JSON, the validation errors will be also be displayed as JSON. Otherwise the errors will be displayed as a simple list.

[paulredmond]

Hi @jessarcher & @taylorotwell!

I've been experimenting with this feature in an example app, and in theory the code works (i.e. tests pass), but in userland tests I don't believe $this->exceptions->last() will ever return a ValidationException instance because it's in the $internalDontReport array in the base Handler class.

This means that ValidationException instances will never be pushed to the LoggedExceptionCollection instance during tests.

A fresh Laravel 8.51 app shows the following error without the expected validation messages:

I am not sure off the top of my head how to get around this, but sure enough this feature works when I remove ValidationException from the $internalDontReport array:

[paulredmond]

This will always return null in the case of ValidationException since it's part of the base Handler internal don't report array:

framework/src/Illuminate/Foundation/Exceptions/Handler.php

Lines 87 to 98 in 63fd6ad

	protected $internalDontReport = [
	AuthenticationException::class,
	AuthorizationException::class,
	HttpException::class,
	HttpResponseException::class,
	ModelNotFoundException::class,
	MultipleRecordsFoundException::class,
	RecordsNotFoundException::class,
	SuspiciousOperationException::class,
	TokenMismatchException::class,
	ValidationException::class,
	];

[jessarcher]

I've been experimenting with this feature in an example app, and in theory the code works (i.e. tests pass), but in userland tests I don't believe $this->exceptions->last() will ever return a ValidationException instance because it's in the $internalDontReport array in the base Handler class.

Crap. Thanks for catching this! I'm working on a solution that checks the response for session errors and errors in the content.