Give SPOT to DefaultPluginXmlFactory cure feature envy leveraging OOP

Author: Vincent Potucek

api/maven-api-core/src/main/java/org/apache/maven/api/services/xml/XmlReaderRequest.java

@@ -78,6 +78,12 @@ interface Transformer {
         String transform(String source, String fieldName);
     }
 
+    default void assertReadable() {
+        if (getInputStream() == null && getReader() == null && getPath() == null && getURL() == null) {
+            throw new IllegalArgumentException("writer, outputStream or path must be non null");
+        }
+    }
+
     @Nonnull
     static XmlReaderRequestBuilder builder() {
         return new XmlReaderRequestBuilder();

api/maven-api-core/src/main/java/org/apache/maven/api/services/xml/XmlWriterRequest.java

@@ -55,6 +55,12 @@ static <T> XmlWriterRequestBuilder<T> builder() {
         return new XmlWriterRequestBuilder<>();
     }
 
+    default void assertWritable() {
+        if (getWriter() == null && getOutputStream() == null && getPath() == null) {
+            throw new IllegalArgumentException("writer, outputStream or path must be non null");
+        }
+    }
+
     class XmlWriterRequestBuilder<T> {
         Path path;
         OutputStream outputStream;

impl/maven-impl/src/main/java/org/apache/maven/impl/DefaultModelXmlFactory.java

@@ -120,9 +120,7 @@ public void write(XmlWriterRequest<Model> request) throws XmlWriterException {
         OutputStream outputStream = request.getOutputStream();
         Writer writer = request.getWriter();
         Function<Object, String> inputLocationFormatter = request.getInputLocationFormatter();
-        if (writer == null && outputStream == null && path == null) {
-            throw new IllegalArgumentException("writer, outputStream or path must be non null");
-        }
+        request.assertWritable();
         try {
             MavenStaxWriter w = new MavenStaxWriter();
             if (inputLocationFormatter != null) {

impl/maven-impl/src/main/java/org/apache/maven/impl/DefaultPluginXmlFactory.java

@@ -18,13 +18,10 @@
  */
 package org.apache.maven.impl;
 
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.io.Reader;
-import java.io.Writer;
-import java.net.URL;
+import javax.xml.stream.XMLStreamException;
+
+import java.io.IOException;
 import java.nio.file.Files;
-import java.nio.file.Path;
 
 import org.apache.maven.api.annotations.Nonnull;
 import org.apache.maven.api.di.Named;
@@ -38,65 +35,63 @@
 import org.apache.maven.plugin.descriptor.io.PluginDescriptorStaxReader;
 import org.apache.maven.plugin.descriptor.io.PluginDescriptorStaxWriter;
 
-import static org.apache.maven.impl.ImplUtils.nonNull;
 import static org.apache.maven.impl.StaxLocation.getLocation;
 import static org.apache.maven.impl.StaxLocation.getMessage;
 
 @Named
 @Singleton
 public class DefaultPluginXmlFactory implements PluginXmlFactory {
+
     @Override
     public PluginDescriptor read(@Nonnull XmlReaderRequest request) throws XmlReaderException {
-        nonNull(request, "request");
-        Path path = request.getPath();
-        URL url = request.getURL();
-        Reader reader = request.getReader();
-        InputStream inputStream = request.getInputStream();
-        if (path == null && url == null && reader == null && inputStream == null) {
-            throw new IllegalArgumentException("path, url, reader or inputStream must be non null");
-        }
+        return read(request, setAddDefaultEntities(request, new PluginDescriptorStaxReader()));
+    }
+
+    @Override
+    public void write(XmlWriterRequest<PluginDescriptor> request) throws XmlWriterException {
+        write(request, new PluginDescriptorStaxWriter());
+    }
+
+    private static PluginDescriptor read(XmlReaderRequest request, PluginDescriptorStaxReader reader) {
+        request.assertReadable();
         try {
-            PluginDescriptorStaxReader xml = new PluginDescriptorStaxReader();
-            xml.setAddDefaultEntities(request.isAddDefaultEntities());
-            if (inputStream != null) {
-                return xml.read(inputStream, request.isStrict());
-            } else if (reader != null) {
-                return xml.read(reader, request.isStrict());
-            } else if (path != null) {
-                try (InputStream is = Files.newInputStream(path)) {
-                    return xml.read(is, request.isStrict());
+            if (request.getInputStream() != null) {
+                return reader.read(request.getInputStream(), request.isStrict());
+            } else if (request.getReader() != null) {
+                return reader.read(request.getReader(), request.isStrict());
+            } else if (request.getPath() != null) {
+                try (var is = Files.newInputStream(request.getPath())) {
+                    return reader.read(is, request.isStrict());
                 }
             } else {
-                try (InputStream is = url.openStream()) {
-                    return xml.read(is, request.isStrict());
+                try (var is = request.getURL().openStream()) {
+                    return reader.read(is, request.isStrict());
                 }
             }
-        } catch (Exception e) {
+        } catch (IOException | XMLStreamException e) {
             throw new XmlReaderException("Unable to read plugin: " + getMessage(e), getLocation(e), e);
         }
     }
 
-    @Override
-    public void write(XmlWriterRequest<PluginDescriptor> request) throws XmlWriterException {
-        nonNull(request, "request");
-        PluginDescriptor content = nonNull(request.getContent(), "content");
-        Path path = request.getPath();
-        OutputStream outputStream = request.getOutputStream();
-        Writer writer = request.getWriter();
-        if (writer == null && outputStream == null && path == null) {
-            throw new IllegalArgumentException("writer, outputStream or path must be non null");
-        }
+    private static PluginDescriptorStaxReader setAddDefaultEntities(
+            XmlReaderRequest request, PluginDescriptorStaxReader reader) {
+        reader.setAddDefaultEntities(request.isAddDefaultEntities());
+        return reader;
+    }
+
+    private static void write(XmlWriterRequest<PluginDescriptor> request, PluginDescriptorStaxWriter writer) {
+        request.assertWritable();
         try {
-            if (writer != null) {
-                new PluginDescriptorStaxWriter().write(writer, content);
-            } else if (outputStream != null) {
-                new PluginDescriptorStaxWriter().write(outputStream, content);
+            if (request.getWriter() != null) {
+                writer.write(request.getWriter(), request.getContent());
+            } else if (request.getOutputStream() != null) {
+                writer.write(request.getOutputStream(), request.getContent());
             } else {
-                try (OutputStream os = Files.newOutputStream(path)) {
-                    new PluginDescriptorStaxWriter().write(os, content);
+                try (var os = Files.newOutputStream(request.getPath())) {
+                    writer.write(os, request.getContent());
                 }
             }
-        } catch (Exception e) {
+        } catch (XmlWriterException | XMLStreamException | IOException e) {
             throw new XmlWriterException("Unable to write plugin: " + getMessage(e), getLocation(e), e);
         }
     }

impl/maven-impl/src/test/java/org/apache/maven/impl/DefaultPluginXmlFactoryTest.java

@@ -46,6 +46,7 @@
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.when;
 
 class DefaultPluginXmlFactoryReadWriteTest {
@@ -82,10 +83,10 @@ void readFromInputStreamParsesPluginDescriptorCorrectly() {
     @Test
     void parsePlugin() {
         assertThat(defaultPluginXmlFactory
-                        .read(XmlReaderRequest.builder()
-                                .reader(new StringReader(SAMPLE_PLUGIN_XML))
-                                .build())
-                        .getName())
+                .read(XmlReaderRequest.builder()
+                        .reader(new StringReader(SAMPLE_PLUGIN_XML))
+                        .build())
+                .getName())
                 .isEqualTo(NAME);
     }
 
@@ -94,8 +95,8 @@ void readFromPathParsesPluginDescriptorCorrectly() throws Exception {
         Path xmlFile = tempDir.resolve("plugin.xml");
         Files.write(xmlFile, SAMPLE_PLUGIN_XML.getBytes());
         assertThat(defaultPluginXmlFactory
-                        .read(XmlReaderRequest.builder().path(xmlFile).build())
-                        .getName())
+                .read(XmlReaderRequest.builder().path(xmlFile).build())
+                .getName())
                 .isEqualTo(NAME);
     }
 
@@ -222,13 +223,13 @@ public void close() {}
     @Test
     void writeWithNoTargetThrowsIllegalArgumentException() {
         assertThat(assertThrows(
-                                IllegalArgumentException.class,
-                                () -> defaultPluginXmlFactory.write(XmlWriterRequest.<PluginDescriptor>builder()
-                                        .content(PluginDescriptor.newBuilder()
-                                                .name("No Output Plugin")
-                                                .build())
-                                        .build()))
-                        .getMessage())
+                IllegalArgumentException.class,
+                () -> defaultPluginXmlFactory.write(XmlWriterRequest.<PluginDescriptor>builder()
+                        .content(PluginDescriptor.newBuilder()
+                                .name("No Output Plugin")
+                                .build())
+                        .build()))
+                .getMessage())
                 .isEqualTo("writer, outputStream or path must be non null");
     }
 
@@ -268,7 +269,7 @@ void readFromUrlParsesPluginDescriptorCorrectly() throws Exception {
     void testReadWithPath() throws Exception {
         Path tempPath = Files.createTempFile("plugin", ".xml");
         Files.writeString(tempPath, "<plugin/>");
-        XmlReaderRequest request = mock(XmlReaderRequest.class);
+        XmlReaderRequest request = spy(XmlReaderRequest.class);
         when(request.getPath()).thenReturn(tempPath);
         when(request.getInputStream()).thenReturn(null);
         when(request.getReader()).thenReturn(null);
@@ -283,7 +284,7 @@ void testReadWithPath() throws Exception {
     void testReadWithPathUrlDefault() throws Exception {
         Path tempPath = Files.createTempFile("plugin", ".xml");
         Files.writeString(tempPath, "<plugin/>");
-        XmlReaderRequest request = mock(XmlReaderRequest.class);
+        XmlReaderRequest request = spy(XmlReaderRequest.class);
         when(request.getPath()).thenReturn(null);
         when(request.getInputStream()).thenReturn(null);
         when(request.getReader()).thenReturn(null);