fix(jmcagent): Move jfrprobes_schema.xsd to correct location, add Pro…

…beValidatorTest (#452)

cryostat-core/src/test/java/io/cryostat/core/jmcagent/ProbeValidatorTest.java

@@ -0,0 +1,159 @@
+/*
+ * Copyright The Cryostat Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.cryostat.core.jmcagent;
+
+import java.io.ByteArrayInputStream;
+import java.nio.charset.StandardCharsets;
+
+import javax.xml.transform.stream.StreamSource;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.xml.sax.ErrorHandler;
+import org.xml.sax.SAXException;
+import org.xml.sax.SAXParseException;
+
+@ExtendWith(MockitoExtension.class)
+public class ProbeValidatorTest {
+
+    final String VALID_XML =
+            "<jfragent>\n"
+                    + //
+                    "\t<events>\n"
+                    + //
+                    "\t\t<event id=\"demo.jfr.test1\">\n"
+                    + //
+                    "\t\t\t<label>JFR Hello World Event 1 %TEST_NAME%</label>\n"
+                    + //
+                    "\t\t\t<description>Defined in the xml file and added by the"
+                    + " agent.</description>\n"
+                    + //
+                    "\t\t\t<path>demo/jfrhelloworldevent1</path>\n"
+                    + //
+                    "\t\t\t<stacktrace>true</stacktrace>\n"
+                    + //
+                    "\t\t\t<class>org.openjdk.jmc.agent.test.InstrumentMe</class>\n"
+                    + //
+                    "\t\t\t<method>\n"
+                    + //
+                    "\t\t\t\t<name>printHelloWorldJFR1</name>\n"
+                    + //
+                    "\t\t\t\t<descriptor>()V</descriptor>\n"
+                    + //
+                    "\t\t\t</method>\n"
+                    + //
+                    "\t\t\t<!-- location {ENTRY, EXIT, WRAP}-->\n"
+                    + //
+                    "\t\t\t<location>WRAP</location>\n"
+                    + //
+                    "\t\t\t<fields>\n"
+                    + //
+                    "\t\t\t\t<field>\n"
+                    + //
+                    "\t\t\t\t\t<name>'InstrumentMe.STATIC_STRING_FIELD'</name>\n"
+                    + //
+                    "\t\t\t\t\t<description>Capturing outer class field with class name prefixed"
+                    + " field name</description>\n"
+                    + //
+                    "\t\t\t\t\t<expression>InstrumentMe.STATIC_STRING_FIELD</expression>\n"
+                    + //
+                    "\t\t\t\t</field>\n"
+                    + //
+                    "\t\t\t</fields>\n"
+                    + //
+                    "\t\t</event>\n"
+                    + //
+                    "\t</events>\n"
+                    + //
+                    "</jfragent>";
+
+    final String INVALID_XML =
+            "<jfragent>\n"
+                    + //
+                    "\t<foo>\n"
+                    + //
+                    "\t<bar>\n"
+                    + //
+                    "'This XML is not a valid probe template'\n"
+                    + //
+                    "\t</bar>\n"
+                    + //
+                    "\t</foo>\n"
+                    + //
+                    "\t</jfragent>";
+
+    ProbeValidator validator;
+
+    @BeforeEach
+    void setUp() {
+        validator = new ProbeValidator();
+    }
+
+    @Test
+    void shouldThrowProbeValidationErrorOnFailure() {
+        JMCAgentXMLStream stream =
+                new JMCAgentXMLStream(
+                        new ByteArrayInputStream(INVALID_XML.getBytes(StandardCharsets.UTF_8)));
+        Assertions.assertThrows(
+                ProbeValidationException.class,
+                () -> {
+                    validator.validate(new StreamSource(stream));
+                });
+    }
+
+    @Test
+    void shouldSuccessfullyValidateCorrectTemplate() {
+        JMCAgentXMLStream stream =
+                new JMCAgentXMLStream(
+                        new ByteArrayInputStream(VALID_XML.getBytes(StandardCharsets.UTF_8)));
+        try {
+            validator.validate(new StreamSource(stream));
+        } catch (Exception e) {
+            System.out.println(e.toString());
+            Assertions.fail();
+        }
+    }
+
+    @Test
+    void shouldNotAllowOverridingErrorHandler() {
+        Assertions.assertThrows(
+                UnsupportedOperationException.class,
+                () -> {
+                    validator.setErrorHandler(new TestErrorHandler());
+                });
+    }
+
+    private static class TestErrorHandler implements ErrorHandler {
+
+        @Override
+        public void warning(SAXParseException exception) throws SAXException {
+            throw new SAXException("We shouldn't have reached here");
+        }
+
+        @Override
+        public void error(SAXParseException exception) throws SAXException {
+            throw new SAXException("We shouldn't have reached here");
+        }
+
+        @Override
+        public void fatalError(SAXParseException exception) throws SAXException {
+            throw new SAXException("We shouldn't have reached here");
+        }
+    }
+}