478 jqa tries to load rules from jqa report file (#482)

core/rule/src/main/java/com/buschmais/jqassistant/core/rule/impl/reader/XmlRuleParserPlugin.java

@@ -14,10 +14,12 @@
 import com.buschmais.jqassistant.core.rule.api.source.RuleSource;
 import com.buschmais.jqassistant.core.rule.impl.SourceExecutable;
 import com.buschmais.jqassistant.core.shared.xml.JAXBUnmarshaller;
+import com.buschmais.jqassistant.core.shared.xml.XmlHelper;
 
 import org.jqassistant.schema.rule.v2.*;
 
 import static com.buschmais.jqassistant.core.rule.impl.reader.IndentHelper.removeIndent;
+import static com.buschmais.jqassistant.core.shared.xml.XmlHelper.rootElementMatches;
 import static java.util.stream.Collectors.toSet;
 /**
  * A {@link RuleParserPlugin} implementation.
@@ -38,7 +40,9 @@ public void initialize() {
 
     @Override
     public boolean accepts(RuleSource ruleSource) {
-        return ruleSource.getId().toLowerCase().endsWith(".xml");
+        return ruleSource.getId()
+            .toLowerCase()
+            .endsWith(".xml") && rootElementMatches(ruleSource::getInputStream, qname -> "jqassistant-rules".equals(qname.getLocalPart()));
     }
 
     @Override

core/rule/src/test/java/com/buschmais/jqassistant/core/rule/api/model/XmlRuleParserPluginTest.java

@@ -1,12 +1,15 @@
 package com.buschmais.jqassistant.core.rule.api.model;
 
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
 import java.net.URL;
 import java.util.Collection;
 import java.util.Map;
 import java.util.Set;
 
 import com.buschmais.jqassistant.core.rule.api.configuration.Rule;
 import com.buschmais.jqassistant.core.rule.api.reader.RuleParserPlugin;
+import com.buschmais.jqassistant.core.rule.api.source.RuleSource;
 import com.buschmais.jqassistant.core.rule.api.source.UrlRuleSource;
 import com.buschmais.jqassistant.core.rule.impl.reader.XmlRuleParserPlugin;
 
@@ -18,6 +21,7 @@
 import org.mockito.junit.jupiter.MockitoExtension;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.*;
 
 @ExtendWith(MockitoExtension.class)
 class XmlRuleParserPluginTest {
@@ -112,4 +116,37 @@ void ruleSchema_1_8() throws RuleException {
         assertThat(conceptIds.size()).isEqualTo(1);
         MatcherAssert.assertThat(conceptIds, IsCollectionContaining.hasItems("test"));
     }
+
+    @Test
+    void testAccepts_ValidXmlFile_ReturnsTrue() throws IOException {
+        XmlRuleParserPlugin xmlRuleParserPlugin = new XmlRuleParserPlugin();
+        RuleSource mockRuleSource = mock(RuleSource.class);
+
+        doReturn("jqassistant-rules.xml").when(mockRuleSource)
+            .getId();
+        when(mockRuleSource.getInputStream()).thenReturn(new ByteArrayInputStream("<jqassistant-rules>".getBytes()));
+        assertThat(xmlRuleParserPlugin.accepts(mockRuleSource)).isTrue();
+    }
+
+    @Test
+    void testAccepts_InvalidXmlFile_ReturnsFalse() throws IOException {
+        XmlRuleParserPlugin xmlRuleParserPlugin = new XmlRuleParserPlugin();
+        RuleSource mockRuleSource = mock(RuleSource.class);
+
+        doReturn("jqassistant-report.xml").when(mockRuleSource)
+            .getId();
+        when(mockRuleSource.getInputStream()).thenReturn(new ByteArrayInputStream("<jqassistant-report>".getBytes()));
+        assertThat(xmlRuleParserPlugin.accepts(mockRuleSource)).isFalse();
+    }
+
+    @Test
+    void testAccepts_InvalidXFile_ReturnsFalse() {
+        XmlRuleParserPlugin xmlRuleParserPlugin = new XmlRuleParserPlugin();
+        RuleSource mockRuleSource = mock(RuleSource.class);
+
+        doReturn("report.txt").when(mockRuleSource)
+            .getId();
+        assertThat(xmlRuleParserPlugin.accepts(mockRuleSource)).isFalse();
+    }
+
 }

core/runtime/src/main/java/com/buschmais/jqassistant/core/runtime/impl/plugin/PluginConfigurationReaderImpl.java

@@ -11,10 +11,10 @@
 
 import javax.xml.validation.Schema;
 
-import com.buschmais.jqassistant.core.rule.impl.reader.XmlHelper;
 import com.buschmais.jqassistant.core.runtime.api.plugin.PluginClassLoader;
 import com.buschmais.jqassistant.core.runtime.api.plugin.PluginConfigurationReader;
 import com.buschmais.jqassistant.core.shared.xml.JAXBUnmarshaller;
+import com.buschmais.jqassistant.core.shared.xml.XmlHelper;
 
 import org.jqassistant.schema.plugin.v2.JqassistantPlugin;
 import org.slf4j.Logger;

core/shared/src/main/java/com/buschmais/jqassistant/core/shared/xml/XmlHelper.java

@@ -0,0 +1,75 @@
+package com.buschmais.jqassistant.core.shared.xml;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.function.Predicate;
+
+import javax.xml.XMLConstants;
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.validation.Schema;
+import javax.xml.validation.SchemaFactory;
+
+import lombok.extern.slf4j.Slf4j;
+import org.xml.sax.SAXException;
+
+/**
+ * Provides utility functions for working with XML files.
+ */
+@Slf4j
+public class XmlHelper {
+
+    private final static XMLInputFactory xmlInputFactory;
+
+    static {
+        xmlInputFactory = XMLInputFactory.newInstance();
+        xmlInputFactory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
+    }
+
+    public static XMLInputFactory getXMLInputFactory() {
+        return xmlInputFactory;
+    }
+
+    public static boolean rootElementMatches(InputStreamSupplier inputStreamSupplier, Predicate<QName> rootElementPredicate) {
+        try (InputStream stream = inputStreamSupplier.get()) {
+            XMLStreamReader reader = xmlInputFactory.createXMLStreamReader(stream);
+            while (reader.hasNext()) {
+                if (reader.next() == XMLStreamConstants.START_ELEMENT) {
+                    return rootElementPredicate.test(reader.getName());
+                }
+            }
+        } catch (XMLStreamException e) {
+            log.warn("Cannot parse XML file.");
+        } catch (IOException e) {
+            throw new IllegalStateException("Cannot close XML document.", e);
+        }
+        return false;
+    }
+
+    public interface InputStreamSupplier {
+
+        InputStream get() throws IOException;
+
+    }
+
+    /**
+     * Return a {@link Schema} instance for the given resource.
+     *
+     * @param resource
+     *            The resource.
+     * @return The {@link Schema} instance.
+     */
+    public static Schema getSchema(String resource) {
+        Schema schema;
+        try {
+            SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
+            schema = schemaFactory.newSchema(XmlHelper.class.getResource(resource));
+        } catch (SAXException e) {
+            throw new IllegalStateException("Cannot read rules schema.", e);
+        }
+        return schema;
+    }
+}