Trying to access array offset on value of type null when using RefreshDatabase in Laravel

Question

I am writing tests in a fresh installation of Laravel 6.15 (with Spark 9). My PHP version is PHP 7.4.2. My testing environment is Laravel Valet on MacOS.

I am facing an issue where whenever I use the RefreshDatabase trait as part of a test, all tests fail with the trying to access array offset on value of type null error message.

From reading around the suggestion seems to be to downgrade to PHP 7.3 whenever this error is encountered, however there is no mention in the official documentation that PHP 7.4 isn't supported - is there any other way to resolve the error?

It triggers even if the trait is interested into the Laravel example test:

namespace Tests\Feature;

use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class ExampleTest extends TestCase
{

    Use RefreshDatabase;

    /**
     * A basic test example.
     *
     * @return void
     */
    public function testBasicTest()
    {
        $response = $this->get('/');

        $response->assertStatus(200);
    }
}

Gives

PHPUnit 8.5.2 by Sebastian Bergmann and contributors.

.EE                                                                 3 / 3 (100%)

Time: 212 ms, Memory: 22.00 MB

There were 2 errors:

1) Tests\Feature\ExampleTest::testBasicTest
ErrorException: Trying to access array offset on value of type null

/Users/rory/sites/landlord/vendor/laravel/telescope/src/Watchers/QueryWatcher.php:46
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Events/Dispatcher.php:369
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Events/Dispatcher.php:218
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Connection.php:833
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Connection.php:687
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Connection.php:640
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Connection.php:338
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Connection.php:309
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Schema/Builder.php:75
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Migrations/DatabaseMigrationRepository.php:169
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Migrations/Migrator.php:590
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Console/Migrations/MigrateCommand.php:91
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Database/Console/Migrations/MigrateCommand.php:63
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:32
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Container/Util.php:36
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:90
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Container/BoundMethod.php:34
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Container/Container.php:590
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Console/Command.php:134
/Users/rory/sites/landlord/vendor/symfony/console/Command/Command.php:255
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Console/Command.php:121
/Users/rory/sites/landlord/vendor/symfony/console/Application.php:1012
/Users/rory/sites/landlord/vendor/symfony/console/Application.php:272
/Users/rory/sites/landlord/vendor/symfony/console/Application.php:148
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Console/Application.php:93
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Console/Application.php:185
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Console/Kernel.php:273
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/PendingCommand.php:139
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/PendingCommand.php:238
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/Concerns/InteractsWithConsole.php:56
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/RefreshDatabase.php:40
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/RefreshDatabase.php:17
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/TestCase.php:115
/Users/rory/sites/landlord/vendor/laravel/framework/src/Illuminate/Foundation/Testing/TestCase.php:82

phpunit.xml

<?xml version="1.0" encoding="UTF-8"?>
<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="./vendor/phpunit/phpunit/phpunit.xsd"
         backupGlobals="false"
         backupStaticAttributes="false"
         bootstrap="vendor/autoload.php"
         colors="true"
         convertErrorsToExceptions="true"
         convertNoticesToExceptions="true"
         convertWarningsToExceptions="true"
         processIsolation="false"
         stopOnFailure="false">
    <testsuites>
        <testsuite name="Unit">
            <directory suffix="Test.php">./tests/Unit</directory>
        </testsuite>

        <testsuite name="Feature">
            <directory suffix="Test.php">./tests/Feature</directory>
        </testsuite>
    </testsuites>
    <filter>
        <whitelist processUncoveredFilesFromWhitelist="true">
            <directory suffix=".php">./app</directory>
        </whitelist>
    </filter>
    <php>
        <server name="APP_ENV" value="testing"/>
        <server name="BCRYPT_ROUNDS" value="4"/>
        <server name="CACHE_DRIVER" value="array"/>
        <server name="DB_CONNECTION" value="sqlite"/>
        <server name="DB_DATABASE" value=":memory:"/>
        <server name="MAIL_DRIVER" value="array"/>
        <server name="QUEUE_CONNECTION" value="sync"/>
        <server name="SESSION_DRIVER" value="array"/>
    </php>
</phpunit>

Answer 1

I have finally resolved this issue - which it turns out is related to Telescope being installed and running in tests.

To resolve this issue (and ReflectionException: Class env does not exist related issue) add the following line to the phpunit.xml file between the <php> nodes:

<env name="TELESCOPE_ENABLED" value="false"/>

Answer 2

Adding this to my TestCase class in the Laravel tests root folder solves the issue:

protected function setUp(): void
{
    parent::setUp();
}

seems to be an issue with laravel telescope: https://github.com/laravel/telescope/issues/804

Answer 3

I faced quite a similar issue when i upgraded my php version to 7.4.3. I typed this command

composer update

in my console and the error disappeared.