PHPStan Level 2 fixes

[szepeviktor]

By submitting a PR to this repository, I agree to the terms within the Auth0 Code of Conduct.

Description

@joshcanhelp Started static analysis by @phpstan

References

https://packagist.org/packages/szepeviktor/phpstan-wordpress

Testing

Please consider using PHPStan on at least Level 4.

phpstan.neon.dist

#$ composer require --dev szepeviktor/phpstan-wordpress
#$ vendor/bin/phpstan analyze -l 3

includes:
    - vendor/szepeviktor/phpstan-wordpress/extension.neon
parameters:
    level: max
    inferPrivatePropertyTypeFromConstructor: true
    autoload_files:
        - functions.php
        # FIXME Must comment out require_once twice!!!
        - WP_Auth0.php
    paths:
        - functions.php
        - lib/
    ignoreErrors:
        # Uses func_get_args()
        - '#^Function apply_filters(_ref_array)? invoked with [34567] parameters, 2 required\.$#'

Checklist

• I have added documentation for new/changed functionality in this PR or in auth0.com/docs
• All active GitHub checks for tests, formatting, and security are passing
• The correct base branch is being used, if not master

[joshcanhelp]

Thanks for the contribution here! I have one specific comment in here but, generally ... is this something we can add to CI? And what does it provide beyond the PHPCS scan we have there now?

[szepeviktor]

is this something we can add to CI?

Yes! See #786

And what does it provide beyond the PHPCS scan we have there now?

On Level 0-4 PHPStan corrects critical errors (non-existent things, invalid function calls) and invalid PHPDoc blocks,
although on Level 5-8 more benefits come!

PHPCS can only deliver a very tiny piece of PHPStan.

[joshcanhelp]

❯ composer pre-commit
> "vendor/bin/phpcs"
............................................................ 60 / 66 (91%)
......                                                       66 / 66 (100%)


Time: 15.21 secs; Memory: 22MB

> "vendor/bin/phpunit"
Installing...
Running as single site... To run multisite, use -c tests/phpunit/multisite.xml
Not running ajax tests. To execute these, use --group ajax.
Not running ms-files tests. To execute these, use --group ms-files.
Not running external-http tests. To execute these, use --group external-http.
PHPUnit 6.5.14 by Sebastian Bergmann and contributors.

Runtime:       PHP 7.1.33 with Xdebug 2.6.1
Configuration: ~/Sites/wp-auth0/wp-content/plugins/auth0/phpunit.xml.dist

...............................................................  63 / 409 ( 15%)
............................................................... 126 / 409 ( 30%)
............................................................... 189 / 409 ( 46%)
............................................................... 252 / 409 ( 61%)
............................................................... 315 / 409 ( 77%)
............................................................... 378 / 409 ( 92%)
...............................                                 409 / 409 (100%)

Time: 17.29 seconds, Memory: 48.00MB

OK (409 tests, 1561 assertions)