[OpenAPI Generator] When deleting files, only consider specific packages (#529)

Author: newtork

datamodel/openapi/openapi-generator-maven-plugin/src/main/java/com/sap/cloud/sdk/datamodel/openapi/generator/DataModelGeneratorMojo.java

@@ -107,7 +107,7 @@ public class DataModelGeneratorMojo extends AbstractMojo
     private Boolean sapCopyrightHeader;
 
     /**
-     * Defines whether to delete the output directory prior to the generation.
+     * Defines whether to delete the generated files from output directory prior to the generation.
      */
     @Parameter( property = "openapi.generate.deleteOutputDirectory", defaultValue = "false" )
     private boolean deleteOutputDirectory;

datamodel/openapi/openapi-generator/src/main/java/com/sap/cloud/sdk/datamodel/openapi/generator/DataModelGenerator.java

@@ -11,10 +11,12 @@
 import java.nio.file.Files;
 import java.nio.file.Paths;
 import java.util.List;
+import java.util.function.Predicate;
 
 import javax.annotation.Nonnull;
 
 import org.apache.commons.io.FileUtils;
+import org.apache.commons.io.function.IOConsumer;
 import org.openapitools.codegen.ClientOptInput;
 import org.openapitools.codegen.DefaultGenerator;
 
@@ -107,15 +109,20 @@ private Try<GenerationResult> invokeCodeGeneration( @Nonnull final GenerationCon
         });
     }
 
-    private void cleanOutputDirectoryIfRequested( final GenerationConfiguration generationConfiguration )
+    private void cleanOutputDirectoryIfRequested( final GenerationConfiguration configuration )
         throws IOException
     {
-        final File outputDirectory = FileUtils.getFile(generationConfiguration.getOutputDirectory());
-        if( generationConfiguration.deleteOutputDirectory()
-            && outputDirectory.exists()
-            && outputDirectory.isDirectory() ) {
-            log.info("Deleting output directory \"{}\".", outputDirectory.getAbsolutePath());
-            FileUtils.cleanDirectory(outputDirectory);
+        final File outputDirectory = FileUtils.getFile(configuration.getOutputDirectory());
+        if( configuration.deleteOutputDirectory() && outputDirectory.exists() && outputDirectory.isDirectory() ) {
+            log.info("Cleaning generated folders in output directory \"{}\".", outputDirectory.getAbsolutePath());
+
+            for( final var pckg : List.of(configuration.getModelPackage(), configuration.getApiPackage()) ) {
+                final var file = outputDirectory.toPath().resolve(pckg.replace(".", File.separator)).toFile();
+                if( file.exists() && file.isDirectory() ) {
+                    log.info("Deleting files from directory \"{}\".", file);
+                    IOConsumer.forAll(FileUtils::forceDelete, file);
+                }
+            }
         }
     }
 
@@ -149,17 +156,16 @@ private void assertRequiredFieldsAreFilled( final GenerationConfiguration config
         if( configuration.getInputSpec() == null || configuration.getInputSpec().isEmpty() ) {
             throw new IllegalArgumentException("Input file path is null or empty.");
         }
-
-        if( configuration.getApiPackage() == null || configuration.getApiPackage().isEmpty() ) {
-            throw new IllegalArgumentException("API package is null or empty.");
+        if( configuration.getOutputDirectory() == null || configuration.getOutputDirectory().isEmpty() ) {
+            throw new IllegalArgumentException("Output directory is null or empty.");
         }
 
-        if( configuration.getModelPackage() == null || configuration.getModelPackage().isEmpty() ) {
-            throw new IllegalArgumentException("Model package is null or empty.");
+        final Predicate<String> goodPackage = p -> !p.isEmpty() && !p.startsWith(".") && !p.contains(File.separator);
+        if( configuration.getApiPackage() == null || !goodPackage.test(configuration.getApiPackage()) ) {
+            throw new IllegalArgumentException("API package is null or empty or invalid.");
         }
-
-        if( configuration.getOutputDirectory() == null || configuration.getOutputDirectory().isEmpty() ) {
-            throw new IllegalArgumentException("Output directory is null or empty.");
+        if( configuration.getModelPackage() == null || !goodPackage.test(configuration.getModelPackage()) ) {
+            throw new IllegalArgumentException("Model package is null or empty or invalid.");
         }
     }
 

datamodel/openapi/openapi-generator/src/main/java/com/sap/cloud/sdk/datamodel/openapi/generator/model/GenerationConfiguration.java

@@ -66,10 +66,10 @@ public boolean useSapCopyrightHeader()
     }
 
     /**
-     * Indicates whether to delete the output directory prior to the generation.
+     * Indicates whether to delete the generated files from output directory prior to the generation.
      *
-     * @return {@code true} if the output directory should be deleted before generating the OpenAPI client,
-     *         {@code false} otherwise.
+     * @return {@code true} if the generated files should be deleted from output directory before generating the OpenAPI
+     *         client, {@code false} otherwise.
      */
     public boolean deleteOutputDirectory()
     {

datamodel/openapi/openapi-generator/src/test/java/com/sap/cloud/sdk/datamodel/openapi/generator/DataModelGeneratorUnitTest.java

@@ -306,11 +306,16 @@ void testExceptionIfTemplatesUnavailable()
     @SneakyThrows
     void testCleanOutputDirectory()
     {
-        final File existingFile =
-            Files
-                .createTempFile(outputDirectory, "dummyFile", DataModelGeneratorUnitTest.class.getSimpleName())
-                .toFile();
-        assertThat(existingFile.exists()).isTrue();
+        final Path modelDir = Files.createDirectory(outputDirectory.resolve("model"));
+        final Path apiDir = Files.createDirectory(outputDirectory.resolve("api"));
+
+        final File modelFile = Files.createFile(modelDir.resolve("mymodel.java")).toFile();
+        final File apiFile = Files.createFile(apiDir.resolve("myapi.java")).toFile();
+        final File ignoreFile = Files.createFile(outputDirectory.resolve(".ignore")).toFile();
+
+        assertThat(modelFile.exists()).isTrue();
+        assertThat(apiFile.exists()).isTrue();
+        assertThat(ignoreFile.exists()).isTrue();
 
         final GenerationConfiguration configuration =
             GenerationConfiguration
@@ -326,8 +331,11 @@ void testCleanOutputDirectory()
 
         assertThat(generationResult.isSuccess()).isTrue();
 
-        // assert that the file was deleted
-        assertThat(existingFile.exists()).isFalse();
+        // assert that the java files are deleted
+        assertThat(modelFile.exists()).isFalse();
+        assertThat(apiFile.exists()).isFalse();
+        // assert that the ignore file remains
+        assertThat(ignoreFile.exists()).isTrue();
     }
 
     @Test

release_notes.md

@@ -16,7 +16,9 @@
 
 ### 📈 Improvements
 
-- 
+- \[OpenAPI Generator\] Setting the Maven plugin configuration property `openapi.generate.deleteOutputDirectory` to `true` will no longer result in deletion of all files from the `outputDirectory` prior to generation.
+  Instead, only the `apiPackage`- and `apiPackage`-related directories will be cleaned.
+  This reduces the risk of deleting files unexpectedly and allows for reusing the same `outputDirectory` for multiple generator plugin invocations.
 
 ### 🐛 Fixed Issues