feat(objectionary#2080): Cleanup the code

eo-maven-plugin/src/main/java/org/eolang/maven/TranspileMojo.java

@@ -41,6 +41,7 @@
 import java.util.Collection;
 import java.util.List;
 import java.util.Set;
+import java.util.regex.Pattern;
 import java.util.stream.Collectors;
 import org.apache.maven.plugins.annotations.LifecyclePhase;
 import org.apache.maven.plugins.annotations.Mojo;
@@ -101,6 +102,11 @@ public final class TranspileMojo extends SafeMojo {
         )
     );
 
+    /**
+     * Java extension.
+     */
+    private static final Pattern JAVA_EXT = Pattern.compile(".java", Pattern.LITERAL);
+
     /**
      * The directory where to put pre-transpile files.
      */
@@ -178,7 +184,7 @@ public void exec() throws IOException {
      * Transpile.
      * @param tojo Tojo that should be transpiled.
      * @return Number of transpiled files.
-     * @throws IOException If any issues with I/O
+     * @throws java.io.IOException If any issues with I/O
      */
     private int transpile(final ForeignTojo tojo) throws IOException {
         final int saved;
@@ -215,7 +221,7 @@ private int transpile(final ForeignTojo tojo) throws IOException {
      * @param input The .xmir file
      * @param target The path to transpiled .xmir file
      * @return List of Paths to generated java file
-     * @throws IOException If any issues with I/O
+     * @throws java.io.IOException If any issues with I/O
      */
     private List<Path> transpile(
         final Path src,
@@ -249,31 +255,53 @@ removed, new Rel(src)
         return javas;
     }
 
-    private void cleanUpClasses(final List<Path> save) {
-        System.out.println(save);
-
-        final Set<Path> collect = save.stream().map(
-                p -> this.generatedDir.toPath().relativize(p))
-            .map(p -> getResolve(p))
+    /**
+     * Clean up dirty classes.
+     * The method is trying to fix problem produced by dirty libraries:
+     * <a href="https://github.com/objectionary/eo-strings/issues/147"> eo-strings example </a>
+     * Some libraries by mistake can put ALL their compiled classes right into the final library
+     * jar, instead of only adding atoms. This can cause different runtime errors since the
+     * classpath will contain two classes with the same name:
+     * - The first class file will be added from dirty library
+     * - The second class with the same name will be compiled from the transpiled java file
+     * In order to prevent this, we remove all classes that have the java analog in the
+     * generated sources. In other words, if generated-sources (or generated-test-sources) folder
+     * has java classes, we expect that they will be only compiled from that folder.
+     * @param java The list of java files.
+     */
+    private void cleanUpClasses(final Collection<? extends Path> java) {
+        final Set<Path> unexpected = java.stream()
+            .map(path -> this.generatedDir.toPath().relativize(path))
+            .map(TranspileMojo::classExtension)
+            .map(binary -> this.outputDir.toPath().resolve(binary))
             .collect(Collectors.toSet());
-
-        for (final Path path : collect) {
+        for (final Path binary : unexpected) {
             try {
-                Files.deleteIfExists(outputDir.toPath().resolve(path));
-            } catch (final IOException e) {
-                throw new IllegalStateException(e);
+                Files.deleteIfExists(binary);
+            } catch (final IOException cause) {
+                throw new IllegalStateException(
+                    String.format("Can't delete file %s", binary),
+                    cause
+                );
             }
         }
-        System.out.println(collect);
     }
 
-    private static Path getResolve(final Path p) {
-        final String filename = p.getFileName().toString().replace(".java", ".class");
-        if (p.getParent() != null) {
-            return p.getParent().resolve(filename);
+    /**
+     * Rename java to class.
+     * @param java The java file
+     * @return The class file with the same (java) content.
+     */
+    private static Path classExtension(final Path java) {
+        final Path result;
+        final String filename = TranspileMojo.JAVA_EXT.matcher(java.getFileName().toString())
+            .replaceAll(".class");
+        if (java.getParent() == null) {
+            result = Paths.get(filename);
         } else {
-            return Paths.get(filename);
+            result = java.getParent().resolve(filename);
         }
+        return result;
     }
 
     /**

eo-maven-plugin/src/test/java/org/eolang/maven/UnplaceMojoTest.java

@@ -27,7 +27,6 @@
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.security.SecureRandom;
-import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
@@ -49,7 +48,7 @@
  * @since 0.1
  * @checkstyle LocalFinalVariableNameCheck (100 lines)
  */
-@SuppressWarnings("PMD.AvoidDuplicateLiterals")
+@SuppressWarnings({"PMD.AvoidDuplicateLiterals", "PMD.TooManyMethods"})
 final class UnplaceMojoTest {
 
     /**