Update curl usage and psalm configuration

Author: leonardfischer

psalm.xml

@@ -4,7 +4,7 @@
     resolveFromConfigFile="true"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xmlns="https://getpsalm.org/schema/config"
-    phpVersion="7.4"
+    phpVersion="8.0"
     xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
     errorBaseline="psalm-baseline.xml"
 >

src/API.php

@@ -139,9 +139,9 @@ class API {
     /**
      * cURL resource
      *
-     * @var CurlHandle|resource|false|null
+     * @var CurlHandle|null
      */
-    protected $resource;
+    protected CurlHandle|null $resource = null;
 
     /**
      * Information about last client request
@@ -247,7 +247,7 @@ public function __destruct() {
      * @return bool
      */
     public function isConnected(): bool {
-        return is_resource($this->resource) || $this->resource instanceof CurlHandle;
+        return $this->resource instanceof CurlHandle;
     }
 
     /**
@@ -346,12 +346,14 @@ protected function setCURLOptions(): self {
      * @throws RuntimeException on error
      */
     public function connect(): self {
-        $this->resource = curl_init();
+        $curl = curl_init();
 
-        if (!$this->resource) {
+        if (!$curl instanceof CurlHandle) {
             throw new RuntimeException('Unable to initiate cURL session');
         }
 
+        $this->resource = $curl;
+
         return $this;
     }