implement indexOf for Sequence (#96)

* implement indexOf for Sequence

* fix phpstan

phpstan.neon

@@ -27,7 +27,3 @@ parameters:
 		    count: 1
 		    path: src/Value.php
 
-		-
-			message: '# is marked as impure but does not have any side effects.#'
-			count: 1
-			path: src/Collection/Iterator/EmptyIterator.php

src/Collection/Sequence.php

@@ -4,6 +4,8 @@
 
 namespace Munus\Collection;
 
+use Munus\Value\Comparator;
+
 /**
  * Sequence - immutable sequential data structures.
  *
@@ -40,4 +42,24 @@ abstract public function prepend($element);
      * @return self<T>
      */
     abstract public function prependAll(Traversable $elements);
+
+    /**
+     * Returns the index of the first occurrence of the given element or -1 if this does not contain the given element.
+     *
+     * @param T $element
+     */
+    final public function indexOf($element): int
+    {
+        $sequence = $this;
+        $index = 0;
+        while (!$sequence->isEmpty()) {
+            if (Comparator::equals($element, $sequence->head())) {
+                return $index;
+            }
+            ++$index;
+            $sequence = $sequence->tail();
+        }
+
+        return -1;
+    }
 }

tests/Collection/GenericListTest.php

@@ -10,6 +10,7 @@
 use Munus\Collection\Stream\Collectors;
 use Munus\Collection\Traversable;
 use Munus\Control\Option;
+use Munus\Tests\Stub\Event;
 use PHPUnit\Framework\TestCase;
 
 final class GenericListTest extends TestCase
@@ -232,4 +233,27 @@ public function testFlatMap(): void
             GenericList::ofAll([1, 2, 3])
         ));
     }
+
+    public function testIndexOf(): void
+    {
+        $list = GenericList::of('a', 'b', 'c', 'd', 'e', 'f');
+
+        self::assertSame(0, $list->indexOf('a'));
+        self::assertSame(1, $list->indexOf('b'));
+        self::assertSame(5, $list->indexOf('f'));
+        self::assertSame(-1, $list->indexOf('g'));
+    }
+
+    public function testIndexOfIsUsingComparator(): void
+    {
+        $list = GenericList::of(new Event('1', 'payment.failed'), new Event('2', 'payment.pending'));
+
+        self::assertSame(1, $list->indexOf(new Event('3', 'payment.pending')));
+        self::assertSame(-1, $list->indexOf(new Event('1', 'payment.success')));
+    }
+
+    public function testIndexOfOnEmptyList(): void
+    {
+        self::assertSame(-1, GenericList::empty()->indexOf('a'));
+    }
 }

tests/Collection/StreamTest.php

@@ -9,6 +9,7 @@
 use Munus\Collection\Traversable;
 use Munus\Control\Option;
 use Munus\Lazy;
+use Munus\Tests\Stub\Event;
 use PHPUnit\Framework\TestCase;
 
 final class StreamTest extends TestCase
@@ -282,4 +283,27 @@ public function testFlatMap(): void
             Stream::ofAll([1, 2, 3])
         ));
     }
+
+    public function testIndexOf(): void
+    {
+        $stream = Stream::of('a', 'b', 'c', 'd', 'e', 'f');
+
+        self::assertSame(0, $stream->indexOf('a'));
+        self::assertSame(1, $stream->indexOf('b'));
+        self::assertSame(5, $stream->indexOf('f'));
+        self::assertSame(-1, $stream->indexOf('g'));
+    }
+
+    public function testIndexOfIsUsingComparator(): void
+    {
+        $stream = Stream::of(new Event('1', 'payment.failed'), new Event('2', 'payment.pending'));
+
+        self::assertSame(1, $stream->indexOf(new Event('3', 'payment.pending')));
+        self::assertSame(-1, $stream->indexOf(new Event('1', 'payment.success')));
+    }
+
+    public function testIndexOfOnEmptyStream(): void
+    {
+        self::assertSame(-1, Stream::empty()->indexOf('a'));
+    }
 }