add trait unit tests

tests/phpunit/Traits/XmlTraitTest.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace phpunit\Traits;
+
+use PHPUnit\Framework\TestCase;
+use PHPUnuhi\Traits\XmlTrait;
+use SimpleXMLElement;
+
+class XmlTraitTest extends TestCase
+{
+    use XmlTrait;
+
+
+    /**
+     * @return void
+     */
+    public function testGetAttribute(): void
+    {
+        $xmlNode = new SimpleXMLElement('<root attr1="value1" attr2="value2"/>');
+
+        $attr = $this->getAttribute('attr1', $xmlNode);
+
+        $this->assertEquals('attr1', $attr->getName());
+        $this->assertEquals('value1', $attr->getValue());
+    }
+
+    /**
+     * @return void
+     */
+    public function testGetAttributeNotFoundLeadsToEmpty(): void
+    {
+        $xmlNode = new SimpleXMLElement('<root attr1="value1" attr2="value2"/>');
+
+        $attr = $this->getAttribute('notExisting', $xmlNode);
+
+        $this->assertEquals('notExisting', $attr->getName());
+        $this->assertEquals('', $attr->getValue());
+    }
+
+    /**
+     * @return void
+     */
+    public function testGetAttributes(): void
+    {
+        $xmlNode = new SimpleXMLElement('<root attr1="value1" attr2="value2"/>');
+
+        $attributes = $this->getAttributes($xmlNode);
+
+        $this->assertCount(2, $attributes);
+
+        $this->assertEquals('attr1', $attributes[0]->getName());
+        $this->assertEquals('value1', $attributes[0]->getValue());
+
+        $this->assertEquals('attr2', $attributes[1]->getName());
+        $this->assertEquals('value2', $attributes[1]->getValue());
+    }
+}