[11.x] Add before and after methods to Collection

src/Illuminate/Collections/Collection.php

@@ -1113,6 +1113,54 @@ public function search($value, $strict = false)
         return false;
     }
 
+    /**
+     * Get the item before the given item.
+     *
+     * @param  TValue|(callable(TValue,TKey): bool)  $value
+     * @param  bool  $strict
+     * @return TValue|null
+     */
+    public function before($value, $strict = false)
+    {
+        $key = $this->search($value, $strict);
+
+        if ($key === false) {
+            return null;
+        }
+
+        $position = $this->keys()->search($key);
+
+        if ($position === 0) {
+            return null;
+        }
+
+        return $this->get($this->keys()->get($position - 1));
+    }
+
+    /**
+     * Get the item after the given item.
+     *
+     * @param  TValue|(callable(TValue,TKey): bool)  $value
+     * @param  bool  $strict
+     * @return TValue|null
+     */
+    public function after($value, $strict = false)
+    {
+        $key = $this->search($value, $strict);
+
+        if ($key === false) {
+            return null;
+        }
+
+        $position = $this->keys()->search($key);
+
+        if ($position === $this->keys()->count() - 1) {
+            return null;
+        }
+
+        return $this->get($this->keys()->get($position + 1));
+    }
+
     /**
      * Get and remove the first N items from the collection.
      *

src/Illuminate/Collections/Enumerable.php

@@ -889,6 +889,24 @@ public function reverse();
      */
     public function search($value, $strict = false);
 
+    /**
+     * Get the item before the given item.
+     *
+     * @param  TValue|(callable(TValue,TKey): bool)  $value
+     * @param  bool  $strict
+     * @return TValue|null
+     */
+    public function before($value, $strict = false);
+
+    /**
+     * Get the item after the given item.
+     *
+     * @param  TValue|(callable(TValue,TKey): bool)  $value
+     * @param  bool  $strict
+     * @return TValue|null
+     */
+    public function after($value, $strict = false);
+
     /**
      * Shuffle the items in the collection.
      *

src/Illuminate/Collections/LazyCollection.php

@@ -1082,6 +1082,66 @@ public function search($value, $strict = false)
         return false;
     }
 
+    /**
+     * Get the item before the given item.
+     *
+     * @param  TValue|(callable(TValue,TKey): bool)  $value
+     * @param  bool  $strict
+     * @return TValue|null
+     */
+    public function before($value, $strict = false)
+    {
+        $previous = null;
+
+        /** @var (callable(TValue,TKey): bool) $predicate */
+        $predicate = $this->useAsCallable($value)
+            ? $value
+            : function ($item) use ($value, $strict) {
+                return $strict ? $item === $value : $item == $value;
+            };
+
+        foreach ($this as $key => $item) {
+            if ($predicate($item, $key)) {
+                return $previous;
+            }
+
+            $previous = $item;
+        }
+
+        return null;
+    }
+
+    /**
+     * Get the item after the given item.
+     *
+     * @param  TValue|(callable(TValue,TKey): bool)  $value
+     * @param  bool  $strict
+     * @return TValue|null
+     */
+    public function after($value, $strict = false)
+    {
+        $found = false;
+
+        /** @var (callable(TValue,TKey): bool) $predicate */
+        $predicate = $this->useAsCallable($value)
+            ? $value
+            : function ($item) use ($value, $strict) {
+                return $strict ? $item === $value : $item == $value;
+            };
+
+        foreach ($this as $key => $item) {
+            if ($found) {
+                return $item;
+            }
+
+            if ($predicate($item, $key)) {
+                $found = true;
+            }
+        }
+
+        return null;
+    }
+
     /**
      * Shuffle the items in the collection.
      *

tests/Support/SupportCollectionTest.php

@@ -3702,6 +3702,127 @@ public function testSearchReturnsFalseWhenItemIsNotFound($collection)
         }));
     }
 
+    #[DataProvider('collectionClassProvider')]
+    public function testBeforeReturnsItemBeforeTheGivenItem($collection)
+    {
+        $c = new $collection([1, 2, 3, 4, 5, 2, 5, 'name' => 'taylor', 'framework' => 'laravel']);
+
+        $this->assertEquals(1, $c->before(2));
+        $this->assertEquals(1, $c->before('2'));
+        $this->assertEquals(5, $c->before('taylor'));
+        $this->assertSame('taylor', $c->before('laravel'));
+        $this->assertEquals(4, $c->before(function ($value) {
+            return $value > 4;
+        }));
+        $this->assertEquals(5, $c->before(function ($value) {
+            return ! is_numeric($value);
+        }));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testBeforeInStrictMode($collection)
+    {
+        $c = new $collection([false, 0, 1, [], '']);
+        $this->assertNull($c->before('false', true));
+        $this->assertNull($c->before('1', true));
+        $this->assertNull($c->before(false, true));
+        $this->assertEquals(false, $c->before(0, true));
+        $this->assertEquals(0, $c->before(1, true));
+        $this->assertEquals(1, $c->before([], true));
+        $this->assertEquals([], $c->before('', true));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testBeforeReturnsNullWhenItemIsNotFound($collection)
+    {
+        $c = new $collection([1, 2, 3, 4, 5, 'foo' => 'bar']);
+
+        $this->assertNull($c->before(6));
+        $this->assertNull($c->before('foo'));
+        $this->assertNull($c->before(function ($value) {
+            return $value < 1 && is_numeric($value);
+        }));
+        $this->assertNull($c->before(function ($value) {
+            return $value === 'nope';
+        }));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testBeforeReturnsNullWhenItemOnTheFirstitem($collection)
+    {
+        $c = new $collection([1, 2, 3, 4, 5, 'foo' => 'bar']);
+
+        $this->assertNull($c->before(1));
+        $this->assertNull($c->before(function ($value) {
+            return $value < 2 && is_numeric($value);
+        }));
+
+        $c = new $collection(['foo' => 'bar', 1, 2, 3, 4, 5]);
+        $this->assertNull($c->before('bar'));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testAfterReturnsItemAfterTheGivenItem($collection)
+    {
+        $c = new $collection([1, 2, 3, 4, 2, 5, 'name' => 'taylor', 'framework' => 'laravel']);
+
+        $this->assertEquals(2, $c->after(1));
+        $this->assertEquals(3, $c->after(2));
+        $this->assertEquals(4, $c->after(3));
+        $this->assertEquals(2, $c->after(4));
+        $this->assertEquals('taylor', $c->after(5));
+        $this->assertEquals('laravel', $c->after('taylor'));
+
+        $this->assertEquals(4, $c->after(function ($value) {
+            return $value > 2;
+        }));
+        $this->assertEquals('laravel', $c->after(function ($value) {
+            return ! is_numeric($value);
+        }));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testAfterInStrictMode($collection)
+    {
+        $c = new $collection([false, 0, 1, [], '']);
+
+        $this->assertNull($c->after('false', true));
+        $this->assertNull($c->after('1', true));
+        $this->assertNull($c->after('', true));
+        $this->assertEquals(0, $c->after(false, true));
+        $this->assertEquals([], $c->after(1, true));
+        $this->assertEquals('', $c->after([], true));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testAfterReturnsNullWhenItemIsNotFound($collection)
+    {
+        $c = new $collection([1, 2, 3, 4, 5, 'foo' => 'bar']);
+
+        $this->assertNull($c->after(6));
+        $this->assertNull($c->after('foo'));
+        $this->assertNull($c->after(function ($value) {
+            return $value < 1 && is_numeric($value);
+        }));
+        $this->assertNull($c->after(function ($value) {
+            return $value === 'nope';
+        }));
+    }
+
+    #[DataProvider('collectionClassProvider')]
+    public function testAfterReturnsNullWhenItemOnTheLastItem($collection)
+    {
+        $c = new $collection([1, 2, 3, 4, 5, 'foo' => 'bar']);
+
+        $this->assertNull($c->after('bar'));
+        $this->assertNull($c->after(function ($value) {
+            return $value > 4 && ! is_numeric($value);
+        }));
+
+        $c = new $collection(['foo' => 'bar', 1, 2, 3, 4, 5]);
+        $this->assertNull($c->after(5));
+    }
+
     #[DataProvider('collectionClassProvider')]
     public function testKeys($collection)
     {