src/Debug/Debug.php
public function assert($assertion, $msg = null)
    {
        // "use" our function params so things don't complain
        array($msg);
        $args = \func_get_args();
        $meta = $this->internal->getMetaVals($args);
        $assertion = \array_shift($args);
        if (!$assertion) {
            if (!$args) {
                $callerInfo = $this->utilities->getCallerInfo();
                $args[] = 'Assertion failed in '.$callerInfo['file'].' on line '.$callerInfo['line'];
            }
            $this->appendLog('assert', $args, $meta);
        }
    }
public function assert($assertion, $msg = null)
    {
        // "use" our function params so things don't complain
        array($msg);
        $args = \func_get_args();
        $meta = $this->internal->getMetaVals($args);
        $assertion = \array_shift($args);
        if (!$assertion) {
            if (!$args) {
                $callerInfo = $this->utilities->getCallerInfo();
                $args[] = 'Assertion failed in '.$callerInfo['file'].' on line '.$callerInfo['line'];
            }
            $this->appendLog('assert', $args, $meta);
        }
    }
Log a message and stack trace to console if first argument is false.

Only appends log when assertion fails

Supports styling/substitutions

@param boolean $assertion argument checked for truthyness
@param mixed   $msg,...   (optional) variable num of addititional values to output

@return void