How do I unit test component methods that use the logger?

Question

I have unit tests running for my component (using a bootstrap file to get the usual requirements) but as soon as I add any logging, I get:

Class '\Joomla\CMS\Log\Log' not found`

I have tried mocking out the Log class, but I don't know how to assign my mock to the global JLog namespace. My tests were passing before I added logging to the methods, so I know that the bootstrap is good in principle, it just seems to be the log that is throwing it.

My setup looks like this:

public function setUp():void {
    parent::setUp();
    $this->channel_store = $this->createMock('ChannelStore');
    $this->application = $this->getMockBuilder(JApplication::class)
                              ->setMethods(['get', 'set'])
                              ->getMock();
    JFactory::$application = $this->application;

    $this->log = $this->getMockBuilder(JLog::class)
                      ->setMethods(['add'])
                      ->getMock();

    //  JLog = $this->log; ???
}

What do I need to do in order to mock out JLog correctly?

Answer 1

In the end I didn't find a way to do this through mocking, but it is very simple to implement a class that does everything I need from the logger:

class JLog {
    const DEBUG = 5;
    const INFO = 4;
    const WARNING = 3;
    const ERROR = 2;

    private static $messages;

    public static function add( $message, $level, $report ) {
        if (!self::$messages) {
            self::$messages = array();
        }
        self::$messages[] = $message;
        echo("\r\n".$message); //optionally print the message for troubleshooting tests.
    }
}

Just including this in my test classes or the bootstrap file immediately got my tests working.