test: add sanity checks to some Redis tests

[paulbalandan]

Description
Apparently, Redis is not working on my laptop but the ErrorExceptions are not a graceful way to say so. Test failures should be fine.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value (without duplication)
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide

[neznaika0]

Is this an error after restarting the tests when the values of 101 do not match?

[paulbalandan]

Is this an error after restarting the tests when the values of 101 do not match?

I'm getting that failure earlier where 101 does not match with 203 or something.

This fix only addresses errors on offset access on null.

[neznaika0]

I can't check it, but I also noticed an error. It seems we need a github action without loading the cache - a restart to detect an incorrect test reset. it can be run once a week? Checking on the local PC has so far allowed us to find such errors.

[neznaika0]

I ran the tests, the error is in Predis.

There were 2 failures:
1) CodeIgniter\Cache\Handlers\PredisHandlerTest::testDeleteMatchingPrefix
Failed asserting that two strings are identical.
--- Expected+++ Actual@@ @@-'101'+'102'
tests/system/Cache/Handlers/PredisHandlerTest.php:139
2) CodeIgniter\Cache\Handlers\PredisHandlerTest::testDeleteMatchingSuffix
Failed asserting that two strings are identical.
--- Expected+++ Actual@@ @@-'101'+'102'
tests/system/Cache/Handlers/PredisHandlerTest.php:160

Try running all the tests twice, without clearing anything after the first execution.