Refactor some code to make it cleaner

Author: david-marconis

modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -3575,30 +3575,24 @@ protected CodegenDiscriminator createDiscriminator(String schemaName, Schema sch
         discriminator.getMappedModels().addAll(uniqueDescendants);
 
         // check current schema, all parents and descendants to see if the discriminator property is an enum string
-        List<Schema> schemasToCheckForEnumDiscriminator = new ArrayList<>();
-        schemasToCheckForEnumDiscriminator.add(schema);
-        if (ModelUtils.isComposedSchema(schema)) {
-            ModelUtils.getAllParentsName(schema, openAPI.getComponents().getSchemas(), true).stream()
-                    .map(n -> ModelUtils.getSchema(openAPI, n))
-                    .forEach(schemasToCheckForEnumDiscriminator::add);
-        }
-        uniqueDescendants.stream().map(MappedModel::getModelName)
-                .map(n->ModelUtils.getSchema(openAPI, n))
-                .forEach(schemasToCheckForEnumDiscriminator::add);
-        for (Schema schemaToCheck : schemasToCheckForEnumDiscriminator) {
-            if (schemaToCheck == null) {
-                continue;
-            }
-            boolean hasDiscriminatorEnum = Optional.ofNullable(schemaToCheck.getProperties())
-                    .map(p -> (Schema) p.get(discriminatorPropertyName))
-                    .map(s -> ModelUtils.getReferencedSchema(openAPI, s))
-                    .filter(s -> s instanceof StringSchema && s.getEnum() != null && !s.getEnum().isEmpty())
-                    .isPresent();
-            if (hasDiscriminatorEnum) {
-                discriminator.setIsEnum(true);
-                break;
-            }
-        }
+        Stream<Schema> schemasToCheckForEnumDiscriminator = Stream.concat(
+                Stream.of(schema),
+                Stream.concat(
+                        ModelUtils.isComposedSchema(schema)
+                                ? ModelUtils.getAllParentsName(schema, openAPI.getComponents().getSchemas(), true).stream()
+                                : Stream.of(),
+                        uniqueDescendants.stream().map(MappedModel::getModelName)
+                ).flatMap(s -> Optional.ofNullable(ModelUtils.getSchema(openAPI, s)).stream())
+        );
+
+        boolean isEnum = schemasToCheckForEnumDiscriminator.anyMatch(s -> Optional
+                .ofNullable(s.getProperties())
+                .map(p -> (Schema) p.get(discriminatorPropertyName))
+                .map(s1 -> ModelUtils.getReferencedSchema(openAPI, s1))
+                .filter(s1 -> s1 instanceof StringSchema && s1.getEnum() != null && !s1.getEnum().isEmpty())
+                .isPresent()
+        );
+        discriminator.setIsEnum(isEnum);
 
         return discriminator;
     }

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java

@@ -440,21 +440,22 @@ public CodegenModel fromModel(String name, Schema model) {
 
                 for (final CodegenProperty property : codegenModel.readWriteVars) {
                     CodegenDiscriminator discriminator = parentCodegenModel.discriminator;
-                    if (property.defaultValue == null && discriminator != null && property.name.equals(discriminator.getPropertyName())) {
-                        if (discriminator.getIsEnum()) {
-                            String enumValue = name;
-                            Map<String, String> mapping = Optional.ofNullable(discriminator.getMapping()).orElseGet(Collections::emptyMap);
-                            for (Map.Entry<String, String> e : mapping.entrySet()) {
-                                String schemaName = e.getValue().indexOf('/') < 0 ? e.getValue() : ModelUtils.getSimpleRef(e.getValue());
-                                if (name.equals(schemaName)) {
-                                    enumValue = e.getKey();
-                                    break;
-                                }
+                    if (property.defaultValue != null || discriminator == null || !property.name.equals(discriminator.getPropertyName())) {
+                        continue;
+                    }
+                    if (discriminator.getIsEnum()) {
+                        String enumValue = name;
+                        Map<String, String> mapping = Optional.ofNullable(discriminator.getMapping()).orElseGet(Collections::emptyMap);
+                        for (Map.Entry<String, String> e : mapping.entrySet()) {
+                            String schemaName = e.getValue().indexOf('/') < 0 ? e.getValue() : ModelUtils.getSimpleRef(e.getValue());
+                            if (name.equals(schemaName)) {
+                                enumValue = e.getKey();
+                                break;
                             }
-                            property.defaultValue = toEnumDefaultValue(property, enumValue);
-                        } else {
-                            property.defaultValue = "\"" + name + "\"";
                         }
+                        property.defaultValue = toEnumDefaultValue(property, enumValue);
+                    } else {
+                        property.defaultValue = "\"" + name + "\"";
                     }
                 }
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/utils/ModelUtils.java

@@ -1598,7 +1598,8 @@ public static List<String> getAllParentsName(Schema composedSchema, Map<String,
         return getAllParentsName(composedSchema, allSchemas, includeAncestors, new HashSet<>());
     }
 
-    public static List<String> getAllParentsName(
+    // Use a set of seen names to avoid infinite recursion
+    private static List<String> getAllParentsName(
             Schema composedSchema, Map<String, Schema> allSchemas, boolean includeAncestors, Set<String> seenNames) {
         List<Schema> interfaces = getInterfaces(composedSchema);
         List<String> names = new ArrayList<String>();

modules/openapi-generator/src/test/java/org/openapitools/codegen/java/JavaClientCodegenTest.java

@@ -2287,15 +2287,16 @@ public void testAllOfWithSinglePrimitiveTypeRef() {
         assertNull(files.get("pom.xml"));
     }
 
-    @Test public void testEnumDiscriminatorDefaultValueIsNotString() throws IOException {
+    @Test
+    public void testEnumDiscriminatorDefaultValueIsNotString() {
         final Path output = newTempFolder();
         final OpenAPI openAPI = TestUtils.parseFlattenSpec(
-            "src/test/resources/3_0/enum_discriminator_inheritance.yaml");
+                "src/test/resources/3_0/enum_discriminator_inheritance.yaml");
         JavaClientCodegen codegen = new JavaClientCodegen();
         codegen.setOutputDir(output.toString());
 
         Map<String, File> files = new DefaultGenerator().opts(new ClientOptInput().openAPI(openAPI).config(codegen))
-            .generate().stream().collect(Collectors.toMap(File::getName, Function.identity()));
+                .generate().stream().collect(Collectors.toMap(File::getName, Function.identity()));
 
         List<String> entities = List.of(
                 "Cat",