harden business rules

core/racing/domain/value-objects/CarClass.ts

@@ -0,0 +1,36 @@
+import { z } from "zod";
+
+const CarClassSchema = z
+  .string()
+  .trim()
+  .min(1, "Car class cannot be empty")
+  .max(50, "Car class must be 50 characters or less");
+
+export class CarClass {
+  private readonly _value: string;
+
+  private constructor(value: string) {
+    this._value = value;
+  }
+
+  static create(value: string): CarClass {
+    const validated = CarClassSchema.parse(value);
+    return new CarClass(validated);
+  }
+
+  static fromString(value: string): CarClass {
+    return new CarClass(value);
+  }
+
+  get value(): string {
+    return this._value;
+  }
+
+  equals(other: CarClass): boolean {
+    return this._value === other._value;
+  }
+
+  toString(): string {
+    return this._value;
+  }
+}