Clean output directory before generation

Issue: #279

plugin/src/main/java/com/github/muehmar/gradle/openapi/dsl/SingleSchemaExtension.java

@@ -6,6 +6,7 @@
 import com.github.muehmar.gradle.openapi.generator.settings.EnumDescriptionSettings;
 import com.github.muehmar.gradle.openapi.generator.settings.GetterSuffixesBuilder;
 import com.github.muehmar.gradle.openapi.generator.settings.JsonSupport;
+import com.github.muehmar.gradle.openapi.generator.settings.PackageName;
 import com.github.muehmar.gradle.openapi.generator.settings.PojoNameMappings;
 import com.github.muehmar.gradle.openapi.generator.settings.PojoSettings;
 import com.github.muehmar.gradle.openapi.generator.settings.StagedBuilderSettings;
@@ -149,10 +150,12 @@ public ValidationMethods getValidationMethods() {
     return validationMethods;
   }
 
-  public String getPackageName(Project project) {
-    return Optional.ofNullable(packageName)
-        .orElseGet(() -> String.format("%s.%s.api.model", project.getGroup(), project.getName()))
-        .replace("-", "");
+  public PackageName getPackageName(Project project) {
+    return PackageName.fromString(
+        Optional.ofNullable(packageName)
+            .orElseGet(
+                () -> String.format("%s.%s.api.model", project.getGroup(), project.getName()))
+            .replace("-", ""));
   }
 
   // DSL API

plugin/src/main/java/com/github/muehmar/gradle/openapi/generator/java/generator/parameter/ParameterGenerator.java

@@ -31,7 +31,7 @@ public ParameterGenerator() {
             .topLevel()
             .packageGen(
                 (a, settings, writer) ->
-                    writer.println("package %s.parameter;", settings.getPackageName()))
+                    writer.println("package %s.parameter;", settings.getPackageName().getName()))
             .noJavaDoc()
             .noAnnotations()
             .modifiers(PUBLIC, FINAL)

plugin/src/main/java/com/github/muehmar/gradle/openapi/generator/java/generator/shared/PackageGenerator.java

@@ -7,6 +7,6 @@
 public class PackageGenerator<T> implements Generator<T, PojoSettings> {
   @Override
   public Writer generate(T data, PojoSettings settings, Writer writer) {
-    return writer.println("package %s;", settings.getPackageName());
+    return writer.println("package %s;", settings.getPackageName().getName());
   }
 }

plugin/src/main/java/com/github/muehmar/gradle/openapi/generator/java/model/JavaFileName.java

@@ -28,27 +28,19 @@ public static JavaFileName fromSettingsAndPojo(PojoSettings settings, JavaPojo p
   }
 
   public static JavaFileName fromSettingsAndClassname(PojoSettings settings, JavaName className) {
-    final String packagePath =
-        settings
-            .getPackageName()
-            .replace(".", File.separator)
-            .replaceFirst("^" + File.separator, "");
+    final Path packagePath = settings.getPackageName().asPath();
     final String fileNameString =
-        String.format("%s%s%s.java", packagePath, File.separator, className);
+        String.format("%s%s%s.java", packagePath.toFile(), File.separator, className);
     return new JavaFileName(Paths.get(fileNameString));
   }
 
   public static JavaFileName fromSettingsAndParameter(
       PojoSettings settings, JavaParameter parameter) {
-    final String packagePath =
-        settings
-            .getPackageName()
-            .replace(".", File.separator)
-            .replaceFirst("^" + File.separator, "");
+    final Path packagePath = settings.getPackageName().asPath();
     final String fileNameString =
         String.format(
             "%s%sparameter%s%s.java",
-            packagePath, File.separator, File.separator, parameter.getParamClassName());
+            packagePath.toFile(), File.separator, File.separator, parameter.getParamClassName());
     return new JavaFileName(Paths.get(fileNameString));
   }
 

plugin/src/main/java/com/github/muehmar/gradle/openapi/generator/settings/PackageName.java

@@ -0,0 +1,33 @@
+package com.github.muehmar.gradle.openapi.generator.settings;
+
+import java.io.File;
+import java.io.Serializable;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import lombok.EqualsAndHashCode;
+
+@EqualsAndHashCode
+public class PackageName implements Serializable {
+  private final String name;
+
+  private PackageName(String name) {
+    this.name = name;
+  }
+
+  public static PackageName fromString(String packageName) {
+    return new PackageName(packageName);
+  }
+
+  public String getName() {
+    return name;
+  }
+
+  public Path asPath() {
+    return Paths.get(name.replace(".", File.separator).replaceFirst("^" + File.separator, ""));
+  }
+
+  @Override
+  public String toString() {
+    return name;
+  }
+}

plugin/src/main/java/com/github/muehmar/gradle/openapi/generator/settings/PojoSettings.java

@@ -19,7 +19,7 @@
 @PojoBuilder
 public class PojoSettings implements Serializable {
   JsonSupport jsonSupport;
-  String packageName;
+  PackageName packageName;
   String suffix;
   StagedBuilderSettings stagedBuilder;
   String builderMethodPrefix;

plugin/src/main/java/com/github/muehmar/gradle/openapi/task/GenerateSchemasTask.java

@@ -5,6 +5,7 @@
 import ch.bluecare.commons.data.NonEmptyList;
 import com.github.muehmar.gradle.openapi.dsl.SingleSchemaExtension;
 import com.github.muehmar.gradle.openapi.dsl.WarningsConfig;
+import com.github.muehmar.gradle.openapi.exception.OpenApiGeneratorException;
 import com.github.muehmar.gradle.openapi.generator.GeneratorFactory;
 import com.github.muehmar.gradle.openapi.generator.Generators;
 import com.github.muehmar.gradle.openapi.generator.mapper.MapResult;
@@ -23,10 +24,15 @@
 import com.github.muehmar.gradle.openapi.writer.BaseDirFileWriter;
 import com.github.muehmar.gradle.openapi.writer.FileWriter;
 import com.github.muehmar.gradle.openapi.writer.GeneratedFile;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
+import java.util.Comparator;
 import java.util.Optional;
 import java.util.function.Supplier;
+import java.util.stream.Stream;
 import javax.inject.Inject;
 import org.gradle.api.Action;
 import org.gradle.api.DefaultTask;
@@ -80,6 +86,8 @@ private void runTask() {
     final MapResult mapResult = cachedMapping.get();
     final Generators generators = GeneratorFactory.create(Language.JAVA);
 
+    cleanOutputDir();
+
     mapResult.getPojos().flatMap(pojo -> createPojo(pojo, generators)).forEach(this::writeFile);
 
     mapResult
@@ -108,6 +116,19 @@ private GeneratedFile createParameter(Parameter parameter, Generators generators
     return generators.getParametersGenerator().generate(parameter, pojoSettings.get());
   }
 
+  private void cleanOutputDir() {
+    final Path directory =
+        Paths.get(outputDir.get()).resolve(pojoSettings.get().getPackageName().asPath());
+    if (Files.exists(directory)) {
+      try (final Stream<Path> paths = Files.walk(directory)) {
+        paths.sorted(Comparator.reverseOrder()).map(Path::toFile).forEach(File::delete);
+      } catch (IOException e) {
+        throw new OpenApiGeneratorException(
+            "Error while cleaning the output directory: " + e.getMessage(), e);
+      }
+    }
+  }
+
   private void writeFile(GeneratedFile file) {
     final FileWriter fileWriter = new BaseDirFileWriter(outputDir.get());
     fileWriter.writeFile(file);

plugin/src/test/java/com/github/muehmar/gradle/openapi/generator/settings/TestPojoSettings.java

@@ -14,7 +14,7 @@ private TestPojoSettings() {}
   public static PojoSettings defaultTestSettings() {
     return fullPojoSettingsBuilder()
         .jsonSupport(JsonSupport.JACKSON)
-        .packageName("com.github.muehmar")
+        .packageName(PackageName.fromString("com.github.muehmar"))
         .suffix("Dto")
         .stagedBuilder(defaultStagedBuilderSettings())
         .builderMethodPrefix("set")