Remove DavException usage for parser creation and add tests

src/main/kotlin/at/bitfire/dav4jvm/XmlUtils.kt

@@ -11,7 +11,6 @@
 package at.bitfire.dav4jvm
 
 import at.bitfire.dav4jvm.XmlUtils.FEATURE_RELAXED
-import at.bitfire.dav4jvm.exception.DavException
 import org.xmlpull.v1.XmlPullParser
 import org.xmlpull.v1.XmlPullParserException
 import org.xmlpull.v1.XmlPullParserFactory
@@ -45,6 +44,8 @@ object XmlUtils {
      *
      * First tries to create a namespace-aware parser that supports [FEATURE_RELAXED]. If that
      * fails, it falls back to a namespace-aware parser without relaxed parsing.
+     *
+     * @throws XmlPullParserException when no parser could be created
      */
     fun newPullParser(): XmlPullParser =
         try {
@@ -54,10 +55,8 @@ object XmlUtils {
             null
         }
         ?: standardFactory.newPullParser()
-        ?: throw DavException("Couldn't create XML parser")
 
     fun newSerializer(): XmlSerializer = standardFactory.newSerializer()
-        ?: throw DavException("Couldn't create XML serializer")
 
 
     fun XmlSerializer.insertTag(name: Property.Name, contentGenerator: XmlSerializer.() -> Unit = {}) {
@@ -74,4 +73,4 @@ object XmlUtils {
         return Property.Name(propNs, propName)
     }
 
-}
+}

src/test/kotlin/at/bitfire/dav4jvm/XmlUtilsTest.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright © All Contributors. See LICENSE and AUTHORS in the root directory for details.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ */
+
+package at.bitfire.dav4jvm
+
+import org.junit.Assert.assertNotNull
+import org.junit.Test
+
+class XmlUtilsTest {
+
+    @Test
+    fun newPullParser() {
+        assertNotNull(XmlUtils.newPullParser())
+    }
+
+    @Test
+    fun newSerializer() {
+        assertNotNull(XmlUtils.newSerializer())
+    }
+
+}