Inspired by https://adamwathan.me/2016/11/14/a-better-database-testing-workflow-in-laravel/

DatabaseSetup

<?php

namespace Tests;

use Illuminate\Contracts\Console\Kernel;

/**
 * Original source: https://gist.github.com/mberizzo/013f49d89b96049c5e8c73284efdb071
 *
 */
trait DatabaseSetup
{
    protected static $migrated = false;

    public function setupDatabase()
    {
        if ($this->isInMemory()) {
            $this->setupInMemoryDatabase();
        } else {
            $this->setupTestDatabase();
        }
    }

    protected function isInMemory()
    {
        return config('database.connections')[config('database.default')]['database'] == ':memory:';
    }

    protected function setupInMemoryDatabase()
    {
        $this->artisan('migrate');
        $this->app[Kernel::class]->setArtisan(null);
    }

    protected function setupTestDatabase()
    {
        if (!static::$migrated) {
            $this->whenMigrationsChange(function($command) {
                $this->artisan($command);

                $this->app[Kernel::class]->setArtisan(null);
            });

            static::$migrated = true;
        }

        $this->beginDatabaseTransaction();
    }

    public function beginDatabaseTransaction()
    {
        $database = $this->app->make('db');
        foreach ($this->connectionsToTransact() as $name) {
            $database->connection($name)->beginTransaction();
        }
        $this->beforeApplicationDestroyed(function () use ($database) {
            foreach ($this->connectionsToTransact() as $name) {
                $database->connection($name)->rollBack();
            }
        });
    }

    protected function connectionsToTransact()
    {
        return property_exists($this, 'connectionsToTransact')
            ? $this->connectionsToTransact : [null];
    }

    protected function whenMigrationsChange($callback)
    {
        $dbTracker = new DatabaseMigrationsTracker;

        if ($dbTracker->dbNameOrMigrationsWereChanged()) {
            $cmd = $dbTracker->getMigrationCommand();
            $callback($cmd);
            $dbTracker->updateContentFiles();
        }
    }
}

/**
 * Track migrations and database name changes
 * in 2 files stored in 'storage/app/*'
 *
 */
class DatabaseMigrationsTracker
{

    protected $storedMigration;
    protected $currentMigration;
    protected $storedDbName;
    protected $currentDbName;
    protected $migrationCommand = 'migrate';

    protected $filesPath = [
        'migrations' => 'app/testing_migrations.txt',
        'db_name' => 'app/testing_database_name.txt',
    ];

    public function __construct()
    {
        $this->readFilesContent();
    }

    protected function readFilesContent()
    {
        $this->storedMigration = $this->getStoredMigrationStr();
        $this->currentMigration = $this->getCurrentMigrationStr();
        $this->storedDbName = $this->getStoredDbName();
        $this->currentDbName = env('DB_DATABASE');
    }

    protected function getStoredMigrationStr()
    {
        $path = storage_path($this->filesPath['migrations']);

        if (file_exists($path)) {
            return file_get_contents($path);
        }

        return '';
    }

    protected function getCurrentMigrationStr()
    {
        return md5(collect(glob(base_path('database/migrations/*')))
            ->map(function ($f) {
                return file_get_contents($f);
            })->implode(''));
    }

    protected function getStoredDbName()
    {
        $path = storage_path($this->filesPath['db_name']);

        if (file_exists($path)) {
            return file_get_contents($path);
        }

        return '';
    }

    public function migrationWasChanged()
    {
        if ($this->storedMigration !== $this->currentMigration) {
            return true;
        }

        return false;
    }

    public function dbNameWasChanged()
    {
        if ($this->storedDbName !== $this->currentDbName) {
            $this->migrationCommand = 'migrate:fresh';
            return true;
        }

        return false;
    }

    public function dbNameOrMigrationsWereChanged()
    {
        if ($this->migrationWasChanged() || $this->dbNameWasChanged()) {
            return true;
        }

        return false;
    }

    public function getMigrationCommand()
    {
        return $this->migrationCommand;
    }

    public function updateContentFiles()
    {
        file_put_contents(
            storage_path($this->filesPath['migrations']),
            $this->currentMigration
        );

        file_put_contents(
            storage_path($this->filesPath['db_name']),
            $this->currentDbName
        );
    }
}