chore(php) bump version to >= 7.4 and <= 8.1 (#9)

* chore(php) bump version to >= 7.4 and <= 8.x

* fix(build) adjust static analysis for PHP 8.1

* chore(deps) update libris to ^2.3.0

* chore(deps) add php ^8.1 to deps

.github/workflows/ci.yaml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php-versions: [ '7.3', '7.4', '8.0' ]
+        php-versions: [ '7.4', '8.0', '8.1' ]
 
     steps:
       - uses: actions/checkout@v2

composer.json

@@ -28,9 +28,9 @@
         }
     ],
     "require": {
-        "php": ">=7.3.0",
+        "php": "^7.4 | ^8.0 | ^8.1",
         "ext-json": "*",
-        "researchgate/libris": "^2.1.1"
+        "researchgate/libris": "^2.3.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^9.3",

src/Model/Container.php

@@ -2,6 +2,7 @@
 
 namespace Geissler\Converter\Model;
 
+use ReturnTypeWillChange;
 use Geissler\Converter\Model\Entry;
 
 /**
@@ -23,14 +24,7 @@ public function __construct()
         $this->data =   [];
     }
 
-    /**
-     * (PHP 5 &gt;= 5.0.0)<br/>
-     * Retrieve an external iterator
-     * @link http://php.net/manual/en/iteratoraggregate.getiterator.php
-     * @return \Traversable An instance of an object implementing <b>Iterator</b> or
-     * <b>Traversable</b>
-     */
-    public function getIterator()
+    public function getIterator(): \ArrayIterator
     {
         return new \ArrayIterator($this->data);
     }
@@ -47,7 +41,7 @@ public function getIterator()
      * <p>
      * The return value will be casted to boolean if non-boolean was returned.
      */
-    public function offsetExists($offset)
+    public function offsetExists($offset): bool
     {
         return isset($this->data[$offset]);
     }
@@ -61,6 +55,7 @@ public function offsetExists($offset)
      * </p>
      * @return mixed Can return all value types.
      */
+    #[ReturnTypeWillChange]
     public function offsetGet($offset)
     {
         return $this->data[$offset] ?? null;
@@ -80,7 +75,7 @@ public function offsetGet($offset)
      * @throws \ErrorException
      * @return void
      */
-    public function offsetSet($offset, $value)
+    public function offsetSet($offset, $value): void
     {
         if (is_object($value) == false) {
             throw new \ErrorException('Only objects are allowed!');
@@ -102,7 +97,7 @@ public function offsetSet($offset, $value)
      * </p>
      * @return void
      */
-    public function offsetUnset($offset)
+    public function offsetUnset($offset): void
     {
         unset($this->data[$offset]);
     }
@@ -117,7 +112,7 @@ public function offsetUnset($offset)
      * <p>
      *       The return value is cast to an integer.
      */
-    public function count()
+    public function count(): int
     {
         return count($this->data);
     }