feat: add anemic model detection and refactor hardcoded values (v0.9.0)

packages/guardian/examples/good-architecture/domain/entities/Customer.ts

@@ -0,0 +1,139 @@
+/**
+ * GOOD EXAMPLE: Rich Domain Model with Business Logic
+ *
+ * This Customer class encapsulates business rules and state transitions.
+ * No public setters - all changes go through business methods.
+ *
+ * This follows Domain-Driven Design and encapsulation principles.
+ */
+
+interface Address {
+    street: string
+    city: string
+    country: string
+    postalCode: string
+}
+
+interface DomainEvent {
+    type: string
+    data: any
+}
+
+class Customer {
+    private readonly id: string
+    private email: string
+    private isActive: boolean
+    private loyaltyPoints: number
+    private address: Address | null
+    private readonly events: DomainEvent[] = []
+
+    constructor(id: string, email: string) {
+        this.id = id
+        this.email = email
+        this.isActive = true
+        this.loyaltyPoints = 0
+        this.address = null
+    }
+
+    public activate(): void {
+        if (this.isActive) {
+            throw new Error("Customer is already active")
+        }
+        this.isActive = true
+        this.events.push({
+            type: "CustomerActivated",
+            data: { customerId: this.id },
+        })
+    }
+
+    public deactivate(reason: string): void {
+        if (!this.isActive) {
+            throw new Error("Customer is already inactive")
+        }
+        this.isActive = false
+        this.events.push({
+            type: "CustomerDeactivated",
+            data: { customerId: this.id, reason },
+        })
+    }
+
+    public changeEmail(newEmail: string): void {
+        if (!this.isValidEmail(newEmail)) {
+            throw new Error("Invalid email format")
+        }
+        if (this.email === newEmail) {
+            return
+        }
+        const oldEmail = this.email
+        this.email = newEmail
+        this.events.push({
+            type: "EmailChanged",
+            data: { customerId: this.id, oldEmail, newEmail },
+        })
+    }
+
+    public updateAddress(address: Address): void {
+        if (!this.isValidAddress(address)) {
+            throw new Error("Invalid address")
+        }
+        this.address = address
+        this.events.push({
+            type: "AddressUpdated",
+            data: { customerId: this.id },
+        })
+    }
+
+    public addLoyaltyPoints(points: number): void {
+        if (points <= 0) {
+            throw new Error("Points must be positive")
+        }
+        if (!this.isActive) {
+            throw new Error("Cannot add points to inactive customer")
+        }
+        this.loyaltyPoints += points
+        this.events.push({
+            type: "LoyaltyPointsAdded",
+            data: { customerId: this.id, points },
+        })
+    }
+
+    public redeemLoyaltyPoints(points: number): void {
+        if (points <= 0) {
+            throw new Error("Points must be positive")
+        }
+        if (this.loyaltyPoints < points) {
+            throw new Error("Insufficient loyalty points")
+        }
+        this.loyaltyPoints -= points
+        this.events.push({
+            type: "LoyaltyPointsRedeemed",
+            data: { customerId: this.id, points },
+        })
+    }
+
+    public getEmail(): string {
+        return this.email
+    }
+
+    public getLoyaltyPoints(): number {
+        return this.loyaltyPoints
+    }
+
+    public getAddress(): Address | null {
+        return this.address ? { ...this.address } : null
+    }
+
+    public getEvents(): DomainEvent[] {
+        return [...this.events]
+    }
+
+    private isValidEmail(email: string): boolean {
+        return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email)
+    }
+
+    private isValidAddress(address: Address): boolean {
+        return !!address.street && !!address.city && !!address.country && !!address.postalCode
+    }
+}
+
+export { Customer }