[Java][jaxrs-spec] enumUnknownDefaultCase true now returns correctly in fromValue (#18910)

* enumUnknownDefaultCase true added for Jaxrs-spec

* Updated tests

---------

Co-authored-by: Dean <dean.kane@opencastsoftware.com>

modules/openapi-generator/src/main/resources/JavaJaxRS/spec/enumClass.mustache

@@ -43,6 +43,6 @@
                 return b;
             }
         }
-        {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
+        {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}{{#enumUnknownDefaultCase}}{{#allowableValues}}{{#enumVars}}{{#-last}}return {{{name}}};{{/-last}}{{/enumVars}}{{/allowableValues}}{{/enumUnknownDefaultCase}}{{^enumUnknownDefaultCase}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/enumUnknownDefaultCase}}{{/isNullable}}
     }
 }

modules/openapi-generator/src/main/resources/JavaJaxRS/spec/enumOuterClass.mustache

@@ -53,6 +53,6 @@ import com.fasterxml.jackson.annotation.JsonValue;
         return b;
       }
     }
-    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/isNullable}}
+    {{#isNullable}}return null;{{/isNullable}}{{^isNullable}}{{#enumUnknownDefaultCase}}{{#allowableValues}}{{#enumVars}}{{#-last}}return {{{name}}};{{/-last}}{{/enumVars}}{{/allowableValues}}{{/enumUnknownDefaultCase}}{{^enumUnknownDefaultCase}}throw new IllegalArgumentException("Unexpected value '" + value + "'");{{/enumUnknownDefaultCase}}{{/isNullable}}
   }
 }

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

@@ -1033,4 +1033,51 @@ public class JavaJAXRSSpecServerCodegenTest extends JavaJaxrsBaseTest {
                         "   info = @org.eclipse.microprofile.openapi.annotations.info.Info(\n" +
                         "        title = \"user\", version=\"1.0.0\", description=\"Operations about user\",");
     }
+
+    @Test
+    public void testEnumUnknownDefaultCaseDeserializationTrue_issue13444() throws Exception {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        OpenAPI openAPI = new OpenAPIParser()
+                .readLocation("src/test/resources/bugs/issue_13444.yaml", null, new ParseOptions()).getOpenAPI();
+
+        codegen.setOutputDir(output.getAbsolutePath());
+        codegen.additionalProperties().put(CodegenConstants.ENUM_UNKNOWN_DEFAULT_CASE, "true");
+
+        ClientOptInput input = new ClientOptInput()
+                .openAPI(openAPI)
+                .config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        Map<String, File> files = generator.opts(input).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+
+        JavaFileAssert.assertThat(files.get("Color.java"))
+                .assertMethod("fromValue").bodyContainsLines("return UNKNOWN_DEFAULT_OPEN_API");
+
+    }
+
+    @Test
+    public void testEnumUnknownDefaultCaseDeserializationNotSet_issue13444() throws Exception {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+
+        OpenAPI openAPI = new OpenAPIParser()
+                .readLocation("src/test/resources/bugs/issue_13444.yaml", null, new ParseOptions()).getOpenAPI();
+
+        codegen.setOutputDir(output.getAbsolutePath());
+
+        ClientOptInput input = new ClientOptInput()
+                .openAPI(openAPI)
+                .config(codegen);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        Map<String, File> files = generator.opts(input).generate().stream()
+                .collect(Collectors.toMap(File::getName, Function.identity()));
+
+        JavaFileAssert.assertThat(files.get("Color.java"))
+                .assertMethod("fromValue").bodyContainsLines("throw new IllegalArgumentException(\"Unexpected value '\" + value + \"'\");");
+
+    }
 }

modules/openapi-generator/src/test/resources/bugs/issue_13444.yaml

@@ -0,0 +1,17 @@
+openapi: "3.0.0"
+info:
+  version: 2.0.0
+  title: test
+paths:
+  /pets:
+    get:
+      summary: List all pets
+      operationId: listPets
+      responses:
+        '200':
+          description: OK
+components:
+  schemas:
+    Color:
+      type: string
+      enum: [RED, BLUE, GREEN]