feat(ADM-018): completed feature

project/src/modules/inventory/domain/errors.ts

@@ -0,0 +1,20 @@
+export class InvalidStockQuantityError extends Error {
+  constructor() {
+    super('Stock quantity must be a positive integer');
+    this.name = 'InvalidStockQuantityError';
+  }
+}
+
+export class InsufficientStockError extends Error {
+  constructor() {
+    super('Insufficient stock available');
+    this.name = 'InsufficientStockError';
+  }
+}
+
+export class InsufficientReservedStockError extends Error {
+  constructor() {
+    super('Insufficient reserved stock');
+    this.name = 'InsufficientReservedStockError';
+  }
+}

project/src/modules/inventory/domain/ports.ts

@@ -0,0 +1,17 @@
+import type { Availability, SetAvailableStockCommand, StockCommand, StockItem } from './stock.js';
+
+export interface InventoryService {
+  checkAvailability(variantId: string, quantity: number): Promise<Availability>;
+  reserve(input: StockCommand): Promise<StockItem>;
+  release(input: StockCommand): Promise<StockItem>;
+  confirm(input: StockCommand): Promise<StockItem>;
+  setAvailable(input: SetAvailableStockCommand): Promise<StockItem>;
+}
+
+export interface InventoryRepository {
+  findByVariantId(variantId: string): Promise<StockItem | undefined>;
+  setAvailable(input: SetAvailableStockCommand): Promise<StockItem>;
+  reserve(input: StockCommand): Promise<StockItem | undefined>;
+  release(input: StockCommand): Promise<StockItem | undefined>;
+  confirm(input: StockCommand): Promise<StockItem | undefined>;
+}

project/src/modules/inventory/domain/stock.ts

@@ -0,0 +1,30 @@
+export type StockState = 'available' | 'reserved' | 'sold' | 'incoming';
+
+export interface StockItem {
+  id: string;
+  variantId: string;
+  available: number;
+  reserved: number;
+  sold: number;
+  incoming: number;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+export interface StockCommand {
+  variantId: string;
+  quantity: number;
+}
+
+export type SetAvailableStockCommand = StockCommand;
+
+export interface Availability {
+  available: boolean;
+  availableQuantity: number;
+}
+
+export function assertPositiveQuantity(quantity: number): void {
+  if (!Number.isInteger(quantity) || quantity <= 0) {
+    throw new Error('Stock quantity must be a positive integer');
+  }
+}