Add support for XML InlineExpectationsTest

java/ql/test/TestUtilities/InlineExpectationsTestPrivate.qll

@@ -20,3 +20,15 @@ private class KtExpectationComment extends KtComment, ExpectationComment {
 
   override string getContents() { result = this.getText().suffix(2).trim() }
 }
+
+private class XMLExpectationComment extends ExpectationComment instanceof XMLComment {
+  override string getContents() { result = this.(XMLComment).getText().trim() }
+
+  override Location getLocation() { result = this.(XMLComment).getLocation() }
+
+  override predicate hasLocationInfo(string path, int sl, int sc, int el, int ec) {
+    this.(XMLComment).hasLocationInfo(path, sl, sc, el, ec)
+  }
+
+  override string toString() { result = this.(XMLComment).toString() }
+}

java/ql/test/library-tests/xml/Test.java

@@ -0,0 +1,3 @@
+public class Test {
+
+}

java/ql/test/library-tests/xml/XMLTest.ql

@@ -0,0 +1,17 @@
+import semmle.code.xml.XML
+import TestUtilities.InlineExpectationsTest
+
+class XMLTest extends InlineExpectationsTest {
+  XMLTest() { this = "XMLTest" }
+
+  override string getARelevantTag() { result = "hasXmlResult" }
+
+  override predicate hasActualResult(Location location, string element, string tag, string value) {
+    tag = "hasXmlResult" and
+    exists(XMLAttribute a |
+      a.getLocation() = location and
+      element = a.toString() and
+      value = ""
+    )
+  }
+}

java/ql/test/library-tests/xml/test.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<document>
+    <element attribute="value">Text</element> <!-- $ hasXmlResult -->
+</document>