From 405c7e546818656a1a2139a721d13cbdbcd92901 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hask=C5=8D?= <hasko@Haskos-MacBook-Air-M5.local>
Date: Tue, 13 Oct 2026 11:07:02 +0200
Subject: [PATCH] =?UTF-8?q?fix(positive-integer):=20=F0=9F=90=9B=20Extend?=
 =?UTF-8?q?=20PositiveNumber=20instead=20of=20Integer?=
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---
 docs/reference/positive-integer.md          |  5 +++--
 src/value-objects/PositiveInteger.ts        |  8 ++++----
 tests/value-objects/PositiveInteger.spec.ts | 13 ++++++++++---
 3 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/docs/reference/positive-integer.md b/docs/reference/positive-integer.md
index 6735c1e..f3610ca 100644
--- a/docs/reference/positive-integer.md
+++ b/docs/reference/positive-integer.md
@@ -16,7 +16,7 @@ import { PositiveInteger } from '@haskou/value-objects';
 ## Signature
 
 ```typescript
-class PositiveInteger extends Integer
+class PositiveInteger extends PositiveNumber
 ```
 
 ## Constructor
@@ -52,7 +52,8 @@ items.divide(2); // throws InvalidIntegerError
 
 ## Notes
 
-- Like `PositiveNumber`, it accepts `0`.
+- Like `PositiveNumber`, it accepts `0`. It is not an `Integer` subclass: `instanceof Integer` is `false`.
+- The sign is checked first, so `-0.5` throws `InvalidPositiveNumberError`, not `InvalidIntegerError`.
 - Arithmetic is inherited from `NumberValueObject` and goes through the constructor, so a result that is negative or not an integer throws.
 
 ## Related
diff --git a/src/value-objects/PositiveInteger.ts b/src/value-objects/PositiveInteger.ts
index c23c37d..43f2fdf 100644
--- a/src/value-objects/PositiveInteger.ts
+++ b/src/value-objects/PositiveInteger.ts
@@ -1,16 +1,16 @@
-import { InvalidPositiveNumberError } from '../errors/InvalidPositiveNumberError';
+import { InvalidIntegerError } from '../errors/InvalidIntegerError';
 import { assert } from '../patterns/Assert';
-import { Integer } from './Integer';
 import { NullObject } from './NullObject';
 import { NumberValueObject } from './NumberValueObject';
+import { PositiveNumber } from './PositiveNumber';
 
-export class PositiveInteger extends Integer {
+export class PositiveInteger extends PositiveNumber {
   constructor(value: number | NumberValueObject) {
     super(value?.valueOf());
 
     if (NullObject.isNullObject(this)) {
       return this;
     }
-    assert(this.value >= 0, new InvalidPositiveNumberError());
+    assert(this.value % 1 === 0, new InvalidIntegerError(this.value));
   }
 }
diff --git a/tests/value-objects/PositiveInteger.spec.ts b/tests/value-objects/PositiveInteger.spec.ts
index 703756e..f08d01a 100644
--- a/tests/value-objects/PositiveInteger.spec.ts
+++ b/tests/value-objects/PositiveInteger.spec.ts
@@ -5,6 +5,7 @@ import {
   InvalidPositiveNumberError,
   NullObject,
   PositiveInteger,
+  PositiveNumber,
 } from '../../src';
 
 describe('PositiveInteger', () => {
@@ -34,7 +35,9 @@ describe('PositiveInteger', () => {
 
     it('should reject non-integer values', () => {
       expect(() => new PositiveInteger(1.5)).toThrow(InvalidIntegerError);
-      expect(() => new PositiveInteger(-0.5)).toThrow(InvalidIntegerError);
+      expect(() => new PositiveInteger(-0.5)).toThrow(
+        InvalidPositiveNumberError,
+      );
     });
 
     it('should reject NaN and infinite values', () => {
@@ -52,8 +55,12 @@ describe('PositiveInteger', () => {
   });
 
   describe('inheritance', () => {
-    it('should inherit from Integer', () => {
-      expect(new PositiveInteger(1)).toBeInstanceOf(Integer);
+    it('should inherit from PositiveNumber', () => {
+      expect(new PositiveInteger(1)).toBeInstanceOf(PositiveNumber);
+    });
+
+    it('should not inherit from Integer', () => {
+      expect(new PositiveInteger(1)).not.toBeInstanceOf(Integer);
     });
 
     it('should not be equal to an Integer with the same value', () => {