[8.x] Add reduceMany to Collections (#39078)

* [8.x] Add `reduceMany` to Collections

* StyleCI

* StyleCI

* Update EnumeratesValues.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>

Author: inxilpro

src/Illuminate/Collections/Traits/EnumeratesValues.php

@@ -15,6 +15,7 @@
 use JsonSerializable;
 use Symfony\Component\VarDumper\VarDumper;
 use Traversable;
+use UnexpectedValueException;
 
 /**
  * @property-read HigherOrderCollectionProxy $average
@@ -744,6 +745,33 @@ public function reduce(callable $callback, $initial = null)
         return $result;
     }
 
+    /**
+     * Reduce the collection to multiple aggregate values.
+     *
+     * @param  callable  $callback
+     * @param  mixed  ...$initial
+     * @return array
+     *
+     * @throws \UnexpectedValueException
+     */
+    public function reduceMany(callable $callback, ...$initial)
+    {
+        $result = $initial;
+
+        foreach ($this as $key => $value) {
+            $result = call_user_func_array($callback, array_merge($result, [$value, $key]));
+
+            if (! is_array($result)) {
+                throw new UnexpectedValueException(sprintf(
+                    "%s::reduceMany expects reducer to return an array, but got a '%s' instead.",
+                    class_basename(static::class), gettype($result)
+                ));
+            }
+        }
+
+        return $result;
+    }
+
     /**
      * Reduce an associative collection to a single value.
      *

tests/Support/SupportCollectionTest.php

@@ -22,6 +22,7 @@
 use ReflectionClass;
 use stdClass;
 use Symfony\Component\VarDumper\VarDumper;
+use UnexpectedValueException;
 
 class SupportCollectionTest extends TestCase
 {
@@ -3902,6 +3903,40 @@ public function testReduceWithKeys($collection)
         }));
     }
 
+    /**
+     * @dataProvider collectionClassProvider
+     */
+    public function testReduceMany($collection)
+    {
+        $data = new $collection([-1, 0, 1, 2, 3, 4, 5]);
+
+        [$sum, $max, $min] = $data->reduceMany(function ($sum, $max, $min, $value) {
+            $sum += $value;
+            $max = max($max, $value);
+            $min = min($min, $value);
+
+            return [$sum, $max, $min];
+        }, 0, PHP_INT_MIN, PHP_INT_MAX);
+
+        $this->assertEquals(14, $sum);
+        $this->assertEquals(5, $max);
+        $this->assertEquals(-1, $min);
+    }
+
+    /**
+     * @dataProvider collectionClassProvider
+     */
+    public function testReduceManyThrowsAnExceptionIfReducerDoesNotReturnAnArray($collection)
+    {
+        $data = new $collection([1]);
+
+        $this->expectException(UnexpectedValueException::class);
+
+        $data->reduceMany(function () {
+            return false;
+        }, null);
+    }
+
     /**
      * @dataProvider collectionClassProvider
      */