Step 00 — Squelette + intégration naïve

3 Bounded Contexts (Sales, Invoicing, LegacyFulfillment) avec :
- Domaines complets (agrégats, VOs, événements, invariants)
- Couche application (commands, queries, ports)
- Infrastructure in-memory (repos, gateway fake)
- Controllers HTTP Symfony
- Couplage naïf synchrone entre BC via NaiveSalesEventPublisher
- 20 tests unitaires et d'intégration passants

src/Invoicing/Application/Command/IssueInvoiceForExternalOrder.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Command;
+
+final readonly class IssueInvoiceForExternalOrder
+{
+    /**
+     * @param list<array{description: string, quantity: int, unitPriceInCents: int, currency: string}> $lines
+     */
+    public function __construct(
+        public string $externalOrderId,
+        public string $customerName,
+        public string $customerAddress,
+        public array $lines,
+    ) {}
+}

src/Invoicing/Application/Command/IssueInvoiceForExternalOrderHandler.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Command;
+
+use MiniShop\Invoicing\Application\Port\InvoiceNumberGenerator;
+use MiniShop\Invoicing\Application\Port\InvoiceRepository;
+use MiniShop\Invoicing\Domain\Model\BillingParty;
+use MiniShop\Invoicing\Domain\Model\Invoice;
+use MiniShop\Invoicing\Domain\Model\InvoiceId;
+use MiniShop\Invoicing\Domain\Model\InvoiceLine;
+use MiniShop\Invoicing\Domain\Model\TaxRate;
+use MiniShop\Shared\Technical\Clock;
+use MiniShop\Shared\Technical\UuidGenerator;
+
+final readonly class IssueInvoiceForExternalOrderHandler
+{
+    public function __construct(
+        private InvoiceRepository $invoiceRepository,
+        private InvoiceNumberGenerator $invoiceNumberGenerator,
+        private Clock $clock,
+    ) {}
+
+    public function __invoke(IssueInvoiceForExternalOrder $command): void
+    {
+        $lines = array_map(
+            static fn (array $line): InvoiceLine => new InvoiceLine(
+                $line['description'],
+                $line['quantity'],
+                $line['unitPriceInCents'],
+                $line['currency'],
+                TaxRate::standard(),
+            ),
+            $command->lines,
+        );
+
+        $invoice = Invoice::issueForExternalOrder(
+            InvoiceId::fromString(UuidGenerator::generate()),
+            $this->invoiceNumberGenerator->next(),
+            $command->externalOrderId,
+            new BillingParty($command->customerName, $command->customerAddress),
+            $lines,
+            $this->clock->now(),
+        );
+
+        $this->invoiceRepository->save($invoice);
+    }
+}

src/Invoicing/Application/Command/MarkInvoiceAsSent.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Command;
+
+final readonly class MarkInvoiceAsSent
+{
+    public function __construct(
+        public string $invoiceId,
+    ) {}
+}

src/Invoicing/Application/Command/MarkInvoiceAsSentHandler.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Command;
+
+use MiniShop\Invoicing\Application\Port\InvoiceRepository;
+use MiniShop\Invoicing\Domain\Model\InvoiceId;
+
+final readonly class MarkInvoiceAsSentHandler
+{
+    public function __construct(
+        private InvoiceRepository $invoiceRepository,
+    ) {}
+
+    public function __invoke(MarkInvoiceAsSent $command): void
+    {
+        $invoice = $this->invoiceRepository->get(InvoiceId::fromString($command->invoiceId));
+        $invoice->markAsSent();
+        $this->invoiceRepository->save($invoice);
+    }
+}

src/Invoicing/Application/Port/InvoiceNumberGenerator.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Port;
+
+interface InvoiceNumberGenerator
+{
+    public function next(): string;
+}

src/Invoicing/Application/Port/InvoiceRepository.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Port;
+
+use MiniShop\Invoicing\Domain\Model\Invoice;
+use MiniShop\Invoicing\Domain\Model\InvoiceId;
+
+interface InvoiceRepository
+{
+    public function save(Invoice $invoice): void;
+
+    public function get(InvoiceId $id): Invoice;
+
+    public function findByExternalOrderId(string $externalOrderId): ?Invoice;
+}

src/Invoicing/Application/Query/GetInvoiceByOrderRef.php

@@ -0,0 +1,12 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Query;
+
+final readonly class GetInvoiceByOrderRef
+{
+    public function __construct(
+        public string $externalOrderId,
+    ) {}
+}

src/Invoicing/Application/Query/GetInvoiceByOrderRefHandler.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Application\Query;
+
+use MiniShop\Invoicing\Application\Port\InvoiceRepository;
+use MiniShop\Invoicing\Domain\Model\Invoice;
+
+final readonly class GetInvoiceByOrderRefHandler
+{
+    public function __construct(
+        private InvoiceRepository $invoiceRepository,
+    ) {}
+
+    public function __invoke(GetInvoiceByOrderRef $query): ?Invoice
+    {
+        return $this->invoiceRepository->findByExternalOrderId($query->externalOrderId);
+    }
+}

src/Invoicing/Domain/Event/InvoiceIssued.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Event;
+
+use MiniShop\Invoicing\Domain\Model\InvoiceId;
+
+final readonly class InvoiceIssued
+{
+    public function __construct(
+        public InvoiceId $invoiceId,
+        public string $invoiceNumber,
+        public string $externalOrderId,
+        public int $totalInclTaxInCents,
+        public \DateTimeImmutable $issuedAt,
+    ) {}
+}

src/Invoicing/Domain/Model/BillingParty.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Model;
+
+final readonly class BillingParty
+{
+    public function __construct(
+        public string $name,
+        public string $address,
+    ) {}
+}

src/Invoicing/Domain/Model/Invoice.php

@@ -0,0 +1,111 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Model;
+
+use MiniShop\Invoicing\Domain\Event\InvoiceIssued;
+
+final class Invoice
+{
+    private InvoiceStatus $status;
+    /** @var list<object> */
+    private array $domainEvents = [];
+
+    /**
+     * @param list<InvoiceLine> $lines
+     */
+    private function __construct(
+        public readonly InvoiceId $id,
+        public readonly string $invoiceNumber,
+        public readonly string $externalOrderId,
+        public readonly BillingParty $billingParty,
+        private readonly array $lines,
+        private readonly \DateTimeImmutable $issuedAt,
+    ) {
+        $this->status = InvoiceStatus::Issued;
+    }
+
+    /**
+     * @param list<InvoiceLine> $lines
+     */
+    public static function issueForExternalOrder(
+        InvoiceId $id,
+        string $invoiceNumber,
+        string $externalOrderId,
+        BillingParty $billingParty,
+        array $lines,
+        \DateTimeImmutable $issuedAt,
+    ): self {
+        if ($lines === []) {
+            throw new \DomainException('An invoice must have at least one line.');
+        }
+
+        $invoice = new self($id, $invoiceNumber, $externalOrderId, $billingParty, $lines, $issuedAt);
+
+        $invoice->recordEvent(new InvoiceIssued(
+            $id,
+            $invoiceNumber,
+            $externalOrderId,
+            $invoice->totalInclTax(),
+            $issuedAt,
+        ));
+
+        return $invoice;
+    }
+
+    public function markAsSent(): void
+    {
+        if ($this->status === InvoiceStatus::Sent) {
+            throw new \DomainException('Invoice is already sent.');
+        }
+
+        $this->status = InvoiceStatus::Sent;
+    }
+
+    public function totalExclTax(): int
+    {
+        return array_sum(array_map(
+            static fn (InvoiceLine $line): int => $line->lineTotalExclTax(),
+            $this->lines,
+        ));
+    }
+
+    public function totalInclTax(): int
+    {
+        return array_sum(array_map(
+            static fn (InvoiceLine $line): int => $line->lineTotalInclTax(),
+            $this->lines,
+        ));
+    }
+
+    public function status(): InvoiceStatus
+    {
+        return $this->status;
+    }
+
+    /** @return list<InvoiceLine> */
+    public function lines(): array
+    {
+        return $this->lines;
+    }
+
+    public function issuedAt(): \DateTimeImmutable
+    {
+        return $this->issuedAt;
+    }
+
+    /** @return list<object> */
+    public function releaseEvents(): array
+    {
+        $events = $this->domainEvents;
+        $this->domainEvents = [];
+
+        return $events;
+    }
+
+    private function recordEvent(object $event): void
+    {
+        $this->domainEvents[] = $event;
+    }
+}

src/Invoicing/Domain/Model/InvoiceId.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Model;
+
+final readonly class InvoiceId
+{
+    private function __construct(public string $value) {}
+
+    public static function fromString(string $value): self
+    {
+        return new self($value);
+    }
+
+    public function toString(): string
+    {
+        return $this->value;
+    }
+
+    public function equals(self $other): bool
+    {
+        return $this->value === $other->value;
+    }
+}

src/Invoicing/Domain/Model/InvoiceLine.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Model;
+
+final readonly class InvoiceLine
+{
+    public function __construct(
+        public string $description,
+        public int $quantity,
+        public int $unitPriceInCents,
+        public string $currency,
+        public TaxRate $taxRate,
+    ) {
+        if ($quantity <= 0) {
+            throw new \InvalidArgumentException('Quantity must be positive.');
+        }
+    }
+
+    public function lineTotalExclTax(): int
+    {
+        return $this->quantity * $this->unitPriceInCents;
+    }
+
+    public function lineTotalInclTax(): int
+    {
+        return (int) round($this->lineTotalExclTax() * (1 + $this->taxRate->rate));
+    }
+}

src/Invoicing/Domain/Model/InvoiceStatus.php

@@ -0,0 +1,11 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Model;
+
+enum InvoiceStatus: string
+{
+    case Issued = 'issued';
+    case Sent = 'sent';
+}

src/Invoicing/Domain/Model/TaxRate.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Domain\Model;
+
+final readonly class TaxRate
+{
+    public function __construct(
+        public float $rate,
+        public string $label,
+    ) {
+        if ($rate < 0 || $rate > 1) {
+            throw new \InvalidArgumentException('Tax rate must be between 0 and 1.');
+        }
+    }
+
+    public static function standard(): self
+    {
+        return new self(0.20, 'TVA 20%');
+    }
+
+    public static function zero(): self
+    {
+        return new self(0.0, 'Exonere');
+    }
+}

src/Invoicing/Infrastructure/Persistence/InMemoryInvoiceRepository.php

@@ -0,0 +1,37 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Infrastructure\Persistence;
+
+use MiniShop\Invoicing\Application\Port\InvoiceRepository;
+use MiniShop\Invoicing\Domain\Model\Invoice;
+use MiniShop\Invoicing\Domain\Model\InvoiceId;
+
+final class InMemoryInvoiceRepository implements InvoiceRepository
+{
+    /** @var array<string, Invoice> */
+    private array $invoices = [];
+
+    public function save(Invoice $invoice): void
+    {
+        $this->invoices[$invoice->id->toString()] = $invoice;
+    }
+
+    public function get(InvoiceId $id): Invoice
+    {
+        return $this->invoices[$id->toString()]
+            ?? throw new \RuntimeException(sprintf('Invoice "%s" not found.', $id->toString()));
+    }
+
+    public function findByExternalOrderId(string $externalOrderId): ?Invoice
+    {
+        foreach ($this->invoices as $invoice) {
+            if ($invoice->externalOrderId === $externalOrderId) {
+                return $invoice;
+            }
+        }
+
+        return null;
+    }
+}

src/Invoicing/Infrastructure/SequentialInvoiceNumberGenerator.php

@@ -0,0 +1,17 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Infrastructure;
+
+use MiniShop\Invoicing\Application\Port\InvoiceNumberGenerator;
+
+final class SequentialInvoiceNumberGenerator implements InvoiceNumberGenerator
+{
+    private int $counter = 0;
+
+    public function next(): string
+    {
+        return sprintf('INV-%06d', ++$this->counter);
+    }
+}

src/Invoicing/Interfaces/Http/GetInvoiceController.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MiniShop\Invoicing\Interfaces\Http;
+
+use MiniShop\Invoicing\Application\Query\GetInvoiceByOrderRef;
+use MiniShop\Invoicing\Application\Query\GetInvoiceByOrderRefHandler;
+use MiniShop\Invoicing\Domain\Model\InvoiceLine;
+use Symfony\Component\HttpFoundation\JsonResponse;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+
+#[Route('/invoicing/orders/{externalOrderId}/invoice', name: 'invoicing_get_invoice', methods: ['GET'])]
+final readonly class GetInvoiceController
+{
+    public function __construct(
+        private GetInvoiceByOrderRefHandler $handler,
+    ) {}
+
+    public function __invoke(string $externalOrderId): JsonResponse
+    {
+        $invoice = ($this->handler)(new GetInvoiceByOrderRef($externalOrderId));
+
+        if ($invoice === null) {
+            return new JsonResponse(['error' => 'Invoice not found.'], Response::HTTP_NOT_FOUND);
+        }
+
+        return new JsonResponse([
+            'invoiceId' => $invoice->id->toString(),
+            'invoiceNumber' => $invoice->invoiceNumber,
+            'externalOrderId' => $invoice->externalOrderId,
+            'billingParty' => [
+                'name' => $invoice->billingParty->name,
+                'address' => $invoice->billingParty->address,
+            ],
+            'status' => $invoice->status()->value,
+            'totalExclTax' => $invoice->totalExclTax(),
+            'totalInclTax' => $invoice->totalInclTax(),
+            'lines' => array_map(
+                static fn (InvoiceLine $line): array => [
+                    'description' => $line->description,
+                    'quantity' => $line->quantity,
+                    'unitPriceInCents' => $line->unitPriceInCents,
+                    'lineTotalExclTax' => $line->lineTotalExclTax(),
+                    'lineTotalInclTax' => $line->lineTotalInclTax(),
+                ],
+                $invoice->lines(),
+            ),
+        ]);
+    }
+}