From 281885a2d58c7ffc0b3e1ac2933fc6df71d90cad Mon Sep 17 00:00:00 2001
From: Julien Rosset <julien.rosset@solulog.fr>
Date: Wed, 11 Oct 2023 19:04:11 +0200
Subject: [PATCH] Fix slice and sliceSelf when collection is empty

---
 src/Collections/Collection.php          | 10 +++++++---
 src/Collections/ImmutableCollection.php |  7 +++++--
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/src/Collections/Collection.php b/src/Collections/Collection.php
index 208b964..211a2eb 100644
--- a/src/Collections/Collection.php
+++ b/src/Collections/Collection.php
@@ -126,9 +126,13 @@ class Collection extends ImmutableCollection implements ICollection {
      * @inheritDoc
      */
     public function sliceSelf (int $offset, ?int $length = null): static {
-        $this->_checkOffset($offset);
-
-        $this->elements = array_slice($this->elements, $offset, $length, true);
+        if ($this->count() === 0) {
+            $this->elements = [];
+        }
+        else {
+            $this->_checkOffset($offset);
+            $this->elements = array_slice($this->elements, $offset, $length, true);
+        }
         return $this;
     }
 
diff --git a/src/Collections/ImmutableCollection.php b/src/Collections/ImmutableCollection.php
index fb62bb7..9a5188a 100644
--- a/src/Collections/ImmutableCollection.php
+++ b/src/Collections/ImmutableCollection.php
@@ -289,9 +289,12 @@ class ImmutableCollection implements IImmutableCollection {
      * @inheritDoc
      */
     public function slice (int $offset, ?int $length = null): static {
-        $this->_checkOffset($offset);
-
         $output = new static();
+        if ($this->count() === 0) {
+            return $output;
+        }
+
+        $this->_checkOffset($offset);
 
         $currentIndex = 0;
         foreach ($this->elements as $key => $value) {