investbrain/tests/TransactionsTest.php

<?php

declare(strict_types=1);

namespace Tests;

use App\Models\Holding;
use App\Models\Portfolio;
use App\Models\Transaction;
use App\Models\User;
use App\Rules\QuantityValidationRule;
use Illuminate\Foundation\Testing\RefreshDatabase;

class TransactionsTest extends TestCase
{
    use RefreshDatabase;

    public function test_can_create_a_transaction(): void
    {
        $this->actingAs($user = User::factory()->create());

        $transaction = Transaction::factory()->create();

        $this->assertNotNull($transaction);
    }

    public function test_sales_calculate_cost_basis(): void
    {
        $this->actingAs($user = User::factory()->create());

        Transaction::factory(5)->buy()->lastYear()->symbol('AAPL')->create();

        $transaction = Transaction::factory()->sell()->lastMonth()->symbol('AAPL')->create();

        $this->assertNotNull($transaction->cost_basis);
    }

    public function test_purchases_dont_have_sale_price(): void
    {
        $this->actingAs($user = User::factory()->create());

        $transaction = Transaction::factory()->buy()->create();

        $this->assertNull($transaction->sale_price);
    }

    public function test_transaction_synced_to_holding(): void
    {
        $this->actingAs($user = User::factory()->create());

        $portfolio = Portfolio::factory()->create();

        Transaction::factory(5)->buy()->lastYear()->portfolio($portfolio->id)->symbol('AAPL')->create();
        $transaction = Transaction::factory()->sell()->lastMonth()->portfolio($portfolio->id)->symbol('AAPL')->create();

        $this->assertDatabaseHas('holdings', [
            'portfolio_id' => $portfolio->id,
            'symbol' => 'AAPL',
            'quantity' => 4,
        ]);

        $holding = Holding::where([
            'portfolio_id' => $portfolio->id,
            'symbol' => 'AAPL',
        ])->first();

        $this->assertEqualsWithDelta(
            $holding->realized_gain_dollars,
            $transaction->sale_price - $transaction->cost_basis,
            0.01
        );
    }

    public function test_cannot_sell_more_than_owned(): void
    {
        $this->actingAs($user = User::factory()->create());

        $portfolio = Portfolio::factory()->create();

        Transaction::factory(5)->buy()->lastYear()->portfolio($portfolio->id)->symbol('AAPL')->create();
        $sale_transaction = Transaction::factory()->sell(6)->lastMonth()->portfolio($portfolio->id)->symbol('AAPL')->make();

        $rule = new QuantityValidationRule($portfolio, $sale_transaction->symbol, 'SELL', $sale_transaction->date, $sale_transaction);

        $rule->validate('quantity', $sale_transaction->quantity, function () {
            $this->assertFalse(false, 'Not permitted to sell more than owned.');
        });

        $this->assertTrue(true);
    }
}