From 9a7df56a75c5f85c93c9bf94cdcd23fae43c59e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Borys=20=C5=BBmuda?= <rudashi@gmail.com>
Date: Sat, 28 Sep 2024 09:44:20 +0200
Subject: [PATCH] feat: Added `Set::difference()` method

---
 src/JavaScript/Set.php | 13 +++++++++++++
 tests/Unit/SetTest.php | 38 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/src/JavaScript/Set.php b/src/JavaScript/Set.php
index 837f863..653b6c0 100644
--- a/src/JavaScript/Set.php
+++ b/src/JavaScript/Set.php
@@ -112,6 +112,19 @@ public function delete(mixed $value): bool
         return false;
     }
 
+    /**
+     * Returns a new Set containing elements in given Set.
+     * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/difference
+     *
+     * @param \Rudashi\JavaScript\Set<TValue> $other
+     *
+     * @return \Rudashi\JavaScript\Set<TValue>
+     */
+    public function difference(Set $other): Set
+    {
+        return new Set(array_diff($this->items, $other->items));
+    }
+
     /**
      * Returns Set value of each element as SetIterator.
      * @link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/entries
diff --git a/tests/Unit/SetTest.php b/tests/Unit/SetTest.php
index d0b86a5..c43cc43 100644
--- a/tests/Unit/SetTest.php
+++ b/tests/Unit/SetTest.php
@@ -276,6 +276,44 @@
     });
 });
 
+describe('difference', function () {
+    test('diff values', function () {
+        $odds = new Set([1, 3, 5, 7, 9]);
+        $squares = new Set([1, 4, 9]);
+
+        expect($odds->difference($squares))
+            ->toBeInstanceOf(Set::class)
+            ->toMatchArray([3, 5, 7]);
+    });
+
+    test('returns empty Set', function () {
+        $a = new Set([1, 2, 3, 4]);
+        $b = new Set([2, 4, 3, 2]);
+
+        expect($b->difference($a))
+            ->toBeInstanceOf(Set::class)
+            ->toMatchArray([]);
+    });
+
+    test('`a` minus `b`', function () {
+        $a = new Set([1, 2, 3, 4]);
+        $b = new Set([5, 4, 3, 2]);
+
+        expect($a->difference($b))
+            ->toBeInstanceOf(Set::class)
+            ->toMatchArray([1]);
+    });
+
+    test('`b` minus `a`', function () {
+        $a = new Set([1, 2, 3, 4]);
+        $b = new Set([5, 4, 3, 2]);
+
+        expect($b->difference($a))
+            ->toBeInstanceOf(Set::class)
+            ->toMatchArray([5]);
+    });
+});
+
 describe('entries', function () {
     it('returns new SetIterator', function () {
         $set = new Set(['foo', 'bar']);