fix conflicts

Author: taylorotwell

Collection.php

@@ -4,6 +4,8 @@
 
 use ArrayAccess;
 use ArrayIterator;
+use Illuminate\Collections\ItemNotFoundException;
+use Illuminate\Collections\MultipleItemsFoundException;
 use Illuminate\Support\Traits\EnumeratesValues;
 use Illuminate\Support\Traits\Macroable;
 use stdClass;
@@ -260,7 +262,7 @@ public function diffKeysUsing($items, callable $callback)
     /**
      * Retrieve duplicate items from the collection.
      *
-     * @param  callable|null  $callback
+     * @param  callable|string|null  $callback
      * @param  bool  $strict
      * @return static
      */
@@ -288,7 +290,7 @@ public function duplicates($callback = null, $strict = false)
     /**
      * Retrieve duplicate items from the collection using strict comparison.
      *
-     * @param  callable|null  $callback
+     * @param  callable|string|null  $callback
      * @return static
      */
     public function duplicatesStrict($callback = null)
@@ -1050,6 +1052,36 @@ public function splitIn($numberOfGroups)
         return $this->chunk(ceil($this->count() / $numberOfGroups));
     }
 
+    /**
+     * Get the first item in the collection, but only if exactly one item exists. Otherwise, throw an exception.
+     *
+     * @param  mixed  $key
+     * @param  mixed  $operator
+     * @param  mixed  $value
+     * @return mixed
+     *
+     * @throws \Illuminate\Collections\ItemNotFoundException
+     * @throws \Illuminate\Collections\MultipleItemsFoundException
+     */
+    public function sole($key = null, $operator = null, $value = null)
+    {
+        $filter = func_num_args() > 1
+            ? $this->operatorForWhere(...func_get_args())
+            : $key;
+
+        $items = $this->when($filter)->filter($filter);
+
+        if ($items->isEmpty()) {
+            throw new ItemNotFoundException;
+        }
+
+        if ($items->count() > 1) {
+            throw new MultipleItemsFoundException;
+        }
+
+        return $items->first();
+    }
+
     /**
      * Chunk the collection into chunks of the given size.
      *

Enumerable.php

@@ -211,7 +211,7 @@ public function diffKeysUsing($items, callable $callback);
     /**
      * Retrieve duplicate items.
      *
-     * @param  callable|null  $callback
+     * @param  callable|string|null  $callback
      * @param  bool  $strict
      * @return static
      */
@@ -220,7 +220,7 @@ public function duplicates($callback = null, $strict = false);
     /**
      * Retrieve duplicate items using strict comparison.
      *
-     * @param  callable|null  $callback
+     * @param  callable|string|null  $callback
      * @return static
      */
     public function duplicatesStrict($callback = null);

ItemNotFoundException.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Illuminate\Collections;
+
+use RuntimeException;
+
+class ItemNotFoundException extends RuntimeException
+{
+}

LazyCollection.php

@@ -316,7 +316,7 @@ public function diffKeysUsing($items, callable $callback)
     /**
      * Retrieve duplicate items.
      *
-     * @param  callable|null  $callback
+     * @param  callable|string|null  $callback
      * @param  bool  $strict
      * @return static
      */
@@ -328,7 +328,7 @@ public function duplicates($callback = null, $strict = false)
     /**
      * Retrieve duplicate items using strict comparison.
      *
-     * @param  callable|null  $callback
+     * @param  callable|string|null  $callback
      * @return static
      */
     public function duplicatesStrict($callback = null)
@@ -1010,6 +1010,31 @@ public function split($numberOfGroups)
         return $this->passthru('split', func_get_args());
     }
 
+    /**
+     * Get the first item in the collection, but only if exactly one item exists. Otherwise, throw an exception.
+     *
+     * @param  mixed  $key
+     * @param  mixed  $operator
+     * @param  mixed  $value
+     * @return mixed
+     *
+     * @throws \Illuminate\Collections\ItemNotFoundException
+     * @throws \Illuminate\Collections\MultipleItemsFoundException
+     */
+    public function sole($key = null, $operator = null, $value = null)
+    {
+        $filter = func_num_args() > 1
+            ? $this->operatorForWhere(...func_get_args())
+            : $key;
+
+        return $this
+            ->when($filter)
+            ->filter($filter)
+            ->take(2)
+            ->collect()
+            ->sole();
+    }
+
     /**
      * Chunk the collection into chunks of the given size.
      *

MultipleItemsFoundException.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Illuminate\Collections;
+
+use RuntimeException;
+
+class MultipleItemsFoundException extends RuntimeException
+{
+}

Traits/EnumeratesValues.php

@@ -740,13 +740,7 @@ public function reduce(callable $callback, $initial = null)
      */
     public function reduceWithKeys(callable $callback, $initial = null)
     {
-        $result = $initial;
-
-        foreach ($this as $key => $value) {
-            $result = $callback($result, $value, $key);
-        }
-
-        return $result;
+        return $this->reduce($callback, $initial);
     }
 
     /**