Fix psalm errors

Author: Kirill Nesmeyanov

src/DocBlock.php

@@ -61,15 +61,11 @@ public function getTags(): array
 
     public function offsetExists(mixed $offset): bool
     {
-        assert(\is_int($offset));
-
         return isset($this->tags[$offset]);
     }
 
     public function offsetGet(mixed $offset): ?TagInterface
     {
-        assert(\is_int($offset));
-
         return $this->tags[$offset] ?? null;
     }
 

src/Parser/Description/RegexDescriptionParser.php

@@ -43,7 +43,10 @@ public function parse(string $description): DescriptionInterface
 
         return match (\count($components)) {
             0 => new Description(),
-            1 => $components[0],
+            1 => match (true) {
+                $components[0] instanceof Description => $components[0],
+                default => new TaggedDescription($components),
+            },
             default => new TaggedDescription($components),
         };
     }

src/Tag/Description/TaggedDescription.php

@@ -60,15 +60,11 @@ public function count(): int
 
     public function offsetExists(mixed $offset): bool
     {
-        assert(\is_int($offset));
-
         return isset($this->tags[$offset]);
     }
 
     public function offsetGet(mixed $offset): TagInterface|DescriptionInterface|null
     {
-        assert(\is_int($offset));
-
         return $this->components[$offset] ?? null;
     }
 

src/Tag/Description/TaggedDescriptionInterface.php

@@ -12,7 +12,7 @@
  * containing an arbitrary set of nested tags ({@see TagInterface}) and,
  * like a parent {@see DescriptionInterface}, can be represented as a string.
  *
- * @template-implements \Traversable<int<0, max>, DescriptionInterface|TagInterface>
+ * @template-extends \Traversable<int<0, max>, DescriptionInterface|TagInterface>
  */
 interface TaggedDescriptionInterface extends
     TagsProviderInterface,