Bail out early if possible

Author: tvdijen

src/TestUtils/SchemaValidationTestTrait.php

@@ -32,12 +32,17 @@ public function testSchemaValidation(): void
         if (!class_exists(self::$testedClass)) {
             $this->markTestSkipped(
                 'Unable to run ' . self::class . '::testSchemaValidation(). Please set ' . self::class
-                . ':$testedClass to a class-string representing the XML-class being tested',
+                . ':$testedClass to a class-string representing the XML-class being tested.',
+            );
+        } elseif (!(self::$testedClass instanceof SchemaValidatableElementInterface)) {
+            $this->markTestSkipped(
+                'Unable to run ' . self::class . '::testSchemaValidation() because the class set in ' . self::class
+                . ':$testedClass does not implement the SchemaValidableElementInterface.',
             );
         } elseif (empty(self::$xmlRepresentation)) {
             $this->markTestSkipped(
                 'Unable to run ' . self::class . '::testSchemaValidation(). Please set ' . self::class
-                . ':$xmlRepresentation to a DOMDocument representing the XML-class being tested',
+                . ':$xmlRepresentation to a DOMDocument representing the XML-class being tested.',
             );
         } else {
             // Validate before serialization

tests/Utils/URIElement.php

@@ -5,9 +5,9 @@
 namespace SimpleSAML\Test\XML;
 
 use SimpleSAML\XML\AbstractElement;
-use SimpleSAML\XML\URIElementTrait;
 use SimpleSAML\XML\SchemaValidatableElementInterface;
 use SimpleSAML\XML\SchemaValidatableElementTrait;
+use SimpleSAML\XML\URIElementTrait;
 
 /**
  * Empty shell class for testing URIElement.