How to write unit test for middleware?

I am new to writing unit tests. I have a created middleware and I need to write unit tests for that using Mockery. Here is my middleware

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;

class SetupSentryContext
{
    /**
     * Handle an incoming request.
     *
     * @param \Illuminate\Http\Request $request
     * @param \Closure $next
     * @return mixed
     */
    public function handle(Request $request, Closure $next)
    {
        config(['optimus.heimdal.reporters.sentry.config.sentry_options.add_context' => function () {
            return $this->addSentryContext();
        }]);

        return $next($request);
    }

    /**
     * @return array
     */
    protected function addSentryContext(): array
    {
        $context = [];
        $context['environment'] = app()->environment();

        $context = $this->getVersionContext($context);
        $context = $this->getUserContext($context);

        // When running in console request is not available
        $context = $this->getNoneCLIContext($context);

        if (isset($context['extra']['exceptions_in_exception_handler'])) {
            $context['tags']['exception'] = 'true';
        }

        return $context;
    }

    /**
     * @param array $context
     * @return array
     */
    protected function getVersionContext(array $context): array
    {
        try {
            $context['release'] = \Tremby\LaravelGitVersion\GitVersionHelper::getVersion();
        } catch (\Tremby\LaravelGitVersion\Exception\CouldNotGetVersionException $exception) {
            $context['release'] = '';
        } catch (\Throwable $throwable) {
            $context['release'] = '';

            $context['extra']['exceptions_in_exception_handler'][] = (string)$throwable;
        }
        return $context;
    }

    /**
     * @param array $context
     * @return array
     */
    protected function getUserContext(array $context): array
    {
        try {
            $user = \User::current();
        } catch (\Symfony\Component\HttpKernel\Exception\UnauthorizedHttpException $exception) {
            $user = null;
        } catch (\Throwable $throwable) {
            $user = null;
            $context['extra']['exceptions_in_exception_handler'][] = (string)$throwable;
        }

        if ($user) {
            $context['user'] = [
                'id' => $user->id,
                'email' => $user->username,
            ];
        } else {
            $context['user'] = [];
        }
        return $context;
    }

    /**
     * @param array $context
     * @return array
     */
    protected function getNoneCLIContext(array $context): array
    {
        if (substr(php_sapi_name(), 0, 3) !== 'cli') {
            $request = app('request');

            if (!isset($context['extra'])) {
                $context['extra'] = [];
            }

            $context['extra']['request_data'] = json_encode($request->all());
            $context = $this->getApiVersionContext($context);
            $context = $this->getUserIP($context);
        }
        return $context;
    }

    /**
     * @param array $context
     * @return array
     */
    protected function getApiVersionContext(array $context): array
    {
        try {
            $context['extra']['api_version'] = app()->get("ApiVersion")->version();
        } catch (\Throwable $throwable) {
            $context['extra']['api_version'] = "unknown";
        }
        return $context;
    }

    /**
     * @param array $context
     * @return array
     */
    protected function getUserIP(array $context): array
    {
        try {
            $context['user']['ip_address'] = \Request::getClientIp();
        } catch (\Symfony\Component\HttpFoundation\Exception\ConflictingHeadersException $exception) {
            $context['user']['ip_address'] = '0.0.0.0';
        } catch (\Throwable $throwable) {
            $context['user']['ip_address'] = '0.0.0.0';

            $context['extra']['exceptions_in_exception_handler'][] = (string)$throwable;
        }
        return $context;
    }
}