diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java
index 1db870ed1b09..bd8595749bb2 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/RubyClientCodegen.java
@@ -295,7 +295,7 @@ public void processOpts() {
             // for Faraday
             additionalProperties.put("isHttpx", Boolean.TRUE);
         } else {
-            throw new RuntimeException("Invalid HTTP library " + getLibrary() + ". Only faraday, typhoeus and httpx are supported.");
+            throw new IllegalArgumentException("Invalid HTTP library " + getLibrary() + ". Only faraday, typhoeus and httpx are supported.");
         }
 
         // test files should not be overwritten
@@ -469,11 +469,11 @@ public String toModelDocFilename(String name) {
     public String toApiFilename(final String name) {
         // replace - with _ e.g. created-at => created_at
         String filename = name;
-        if (apiNameSuffix != null && apiNameSuffix.length() > 0) {
+        if (apiNameSuffix != null && !apiNameSuffix.isEmpty()) {
             filename = filename + "_" + apiNameSuffix;
         }
 
-        filename = filename.replaceAll("-", "_");
+        filename = filename.replace("-", "_");
 
         // e.g. PhoneNumberApi.rb => phone_number_api.rb
         return underscore(filename);
@@ -494,11 +494,6 @@ public String toModelTestFilename(String name) {
         return toModelFilename(name) + "_spec";
     }
 
-    @Override
-    public String toApiName(String name) {
-        return super.toApiName(name);
-    }
-
     @Override
     public String toEnumValue(String value, String datatype) {
         if ("Integer".equals(datatype) || "Float".equals(datatype)) {
@@ -514,16 +509,16 @@ public String toEnumVarName(String name, String datatype) {
             return enumNameMapping.get(name);
         }
 
-        if (name.length() == 0) {
+        if (name.isEmpty()) {
             return "EMPTY";
         }
 
         // number
         if ("Integer".equals(datatype) || "Float".equals(datatype)) {
             String varName = name;
-            varName = varName.replaceAll("-", "MINUS_");
-            varName = varName.replaceAll("\\+", "PLUS_");
-            varName = varName.replaceAll("\\.", "_DOT_");
+            varName = varName.replace("-", "MINUS_");
+            varName = varName.replace("+", "PLUS_");
+            varName = varName.replace(".", "_DOT_");
             return NUMERIC_ENUM_PREFIX + varName;
         }
 
@@ -594,7 +589,7 @@ public String toApiImport(String name) {
 
     @Override
     protected void addAdditionPropertiesToCodeGenModel(CodegenModel codegenModel, Schema schema) {
-        final Schema additionalProperties = ModelUtils.getAdditionalProperties(schema);
+        final Schema<?> additionalProperties = ModelUtils.getAdditionalProperties(schema);
 
         if (additionalProperties != null) {
             codegenModel.additionalPropertiesType = getSchemaType(additionalProperties);
@@ -692,7 +687,7 @@ private String constructExampleCode(CodegenParameter codegenParameter, HashMap<S
             if (modelMaps.containsKey(codegenParameter.dataType)) {
                 return constructExampleCode(modelMaps.get(codegenParameter.dataType), modelMaps, processedModelMap);
             } else {
-                //LOGGER.error("Error in constructing examples. Failed to look up the model " + codegenParameter.dataType);
+                LOGGER.debug("Error in constructing examples. Failed to look up the model " + codegenParameter.dataType);
                 return "TODO";
             }
         }
@@ -702,8 +697,8 @@ private String constructExampleCode(CodegenProperty codegenProperty, HashMap<Str
         if (codegenProperty.isArray) { // array
             if (!StringUtils.isEmpty(codegenProperty.example) && !"null".equals(codegenProperty.example)) {
                 String value = codegenProperty.example;
-                value = value.replaceAll(",", ", ");
-                value = value.replaceAll(":", ": ");
+                value = value.replace(",", ", ");
+                value = value.replace(":", ": ");
                 return value;
             }
             return "[" + constructExampleCode(codegenProperty.items, modelMaps, processedModelMap) + "]";
@@ -764,7 +759,7 @@ private String constructExampleCode(CodegenProperty codegenProperty, HashMap<Str
             if (modelMaps.containsKey(codegenProperty.dataType)) {
                 return constructExampleCode(modelMaps.get(codegenProperty.dataType), modelMaps, processedModelMap);
             } else {
-                //LOGGER.error("Error in constructing examples. Failed to look up the model " + codegenParameter.dataType);
+                LOGGER.debug("Error in constructing examples. Failed to look up the model " + codegenProperty.dataType);
                 return "TODO";
             }
         }
@@ -791,7 +786,7 @@ private String constructExampleCode(CodegenModel codegenModel, HashMap<String, C
                 // oneOf models
                 return constructExampleCode(modelMaps.get(subModel), modelMaps, processedModelMap);
             } else {
-                // TODO oneOf primitive type not supported at the moment
+                // oneOf primitive type not supported at the moment
                 LOGGER.warn("oneOf example value not supported at the moment.");
                 return "nil";
             }
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java
index 68c2254e5a69..4e554969228a 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/ruby/RubyClientCodegenTest.java
@@ -72,7 +72,7 @@ public void testGenerateRubyClientWithHtmlEntity() throws Exception {
     }
 
     @Test
-    public void testInitialConfigValues() throws Exception {
+    public void testInitialConfigValues() {
         final RubyClientCodegen codegen = new RubyClientCodegen();
         codegen.processOpts();
 
@@ -85,7 +85,7 @@ public void testInitialConfigValues() throws Exception {
     }
 
     @Test
-    public void testSettersForConfigValues() throws Exception {
+    public void testSettersForConfigValues() {
         final RubyClientCodegen codegen = new RubyClientCodegen();
         codegen.setHideGenerationTimestamp(false);
         codegen.processOpts();
@@ -95,7 +95,7 @@ public void testSettersForConfigValues() throws Exception {
     }
 
     @Test
-    public void testAdditionalPropertiesPutForConfigValues() throws Exception {
+    public void testAdditionalPropertiesPutForConfigValues() {
         final RubyClientCodegen codegen = new RubyClientCodegen();
         codegen.additionalProperties().put(CodegenConstants.HIDE_GENERATION_TIMESTAMP, false);
         codegen.additionalProperties().put(CodegenConstants.MODEL_PACKAGE, "ruby-models");
@@ -183,7 +183,6 @@ public void nullablePropertyTest() {
         final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/petstore_oas3_test.yaml");
         final RubyClientCodegen codegen = new RubyClientCodegen();
         codegen.setModuleName("OnlinePetstore");
-        final String path = "/pet";
 
         final Schema schema = openAPI.getComponents().getSchemas().get("NullablePet");
         codegen.setOpenAPI(openAPI);
@@ -212,7 +211,6 @@ public void propertiesWithoutNullableTest() {
         final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/petstore_oas3_test.yaml");
         final RubyClientCodegen codegen = new RubyClientCodegen();
         codegen.setModuleName("OnlinePetstore");
-        final String path = "/pet";
 
         final Schema schema = openAPI.getComponents().getSchemas().get("Pet");
         codegen.setOpenAPI(openAPI);
diff --git a/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml b/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
index 064862059da5..c269fb4ee300 100644
--- a/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/ruby/petstore-with-fake-endpoints-models-for-testing.yaml
@@ -1936,6 +1936,7 @@ components:
     OuterEnumInteger:
       type: integer
       enum:
+      - -1
       - 0
       - 1
       - 2
diff --git a/samples/client/petstore/ruby-faraday/docs/FakeApi.md b/samples/client/petstore/ruby-faraday/docs/FakeApi.md
index 1e05788c53ab..a64fa0bc4a35 100644
--- a/samples/client/petstore/ruby-faraday/docs/FakeApi.md
+++ b/samples/client/petstore/ruby-faraday/docs/FakeApi.md
@@ -497,7 +497,7 @@ require 'time'
 require 'petstore'
 
 api_instance = Petstore::FakeApi.new
-outer_object_with_enum_property = Petstore::OuterObjectWithEnumProperty.new({value: Petstore::OuterEnumInteger::N0}) # OuterObjectWithEnumProperty | Input enum (int) as post body
+outer_object_with_enum_property = Petstore::OuterObjectWithEnumProperty.new({value: Petstore::OuterEnumInteger::NMINUS_1}) # OuterObjectWithEnumProperty | Input enum (int) as post body
 
 begin
   
diff --git a/samples/client/petstore/ruby-faraday/lib/petstore/models/outer_enum_integer.rb b/samples/client/petstore/ruby-faraday/lib/petstore/models/outer_enum_integer.rb
index e26193c5a48f..9373d42c5ccd 100644
--- a/samples/client/petstore/ruby-faraday/lib/petstore/models/outer_enum_integer.rb
+++ b/samples/client/petstore/ruby-faraday/lib/petstore/models/outer_enum_integer.rb
@@ -15,12 +15,13 @@
 
 module Petstore
   class OuterEnumInteger
+    NMINUS_1 = -1.freeze
     N0 = 0.freeze
     N1 = 1.freeze
     N2 = 2.freeze
 
     def self.all_vars
-      @all_vars ||= [N0, N1, N2].freeze
+      @all_vars ||= [NMINUS_1, N0, N1, N2].freeze
     end
 
     # Builds the enum from string
diff --git a/samples/client/petstore/ruby-httpx/docs/FakeApi.md b/samples/client/petstore/ruby-httpx/docs/FakeApi.md
index 1e05788c53ab..a64fa0bc4a35 100644
--- a/samples/client/petstore/ruby-httpx/docs/FakeApi.md
+++ b/samples/client/petstore/ruby-httpx/docs/FakeApi.md
@@ -497,7 +497,7 @@ require 'time'
 require 'petstore'
 
 api_instance = Petstore::FakeApi.new
-outer_object_with_enum_property = Petstore::OuterObjectWithEnumProperty.new({value: Petstore::OuterEnumInteger::N0}) # OuterObjectWithEnumProperty | Input enum (int) as post body
+outer_object_with_enum_property = Petstore::OuterObjectWithEnumProperty.new({value: Petstore::OuterEnumInteger::NMINUS_1}) # OuterObjectWithEnumProperty | Input enum (int) as post body
 
 begin
   
diff --git a/samples/client/petstore/ruby-httpx/lib/petstore/models/outer_enum_integer.rb b/samples/client/petstore/ruby-httpx/lib/petstore/models/outer_enum_integer.rb
index e26193c5a48f..9373d42c5ccd 100644
--- a/samples/client/petstore/ruby-httpx/lib/petstore/models/outer_enum_integer.rb
+++ b/samples/client/petstore/ruby-httpx/lib/petstore/models/outer_enum_integer.rb
@@ -15,12 +15,13 @@
 
 module Petstore
   class OuterEnumInteger
+    NMINUS_1 = -1.freeze
     N0 = 0.freeze
     N1 = 1.freeze
     N2 = 2.freeze
 
     def self.all_vars
-      @all_vars ||= [N0, N1, N2].freeze
+      @all_vars ||= [NMINUS_1, N0, N1, N2].freeze
     end
 
     # Builds the enum from string
diff --git a/samples/client/petstore/ruby/docs/FakeApi.md b/samples/client/petstore/ruby/docs/FakeApi.md
index 1dff682f9a2d..57de301f727c 100644
--- a/samples/client/petstore/ruby/docs/FakeApi.md
+++ b/samples/client/petstore/ruby/docs/FakeApi.md
@@ -497,7 +497,7 @@ require 'time'
 require 'petstore'
 
 api_instance = Petstore::FakeApi.new
-outer_object_with_enum_property = Petstore::OuterObjectWithEnumProperty.new({value: Petstore::OuterEnumInteger::N0}) # OuterObjectWithEnumProperty | Input enum (int) as post body
+outer_object_with_enum_property = Petstore::OuterObjectWithEnumProperty.new({value: Petstore::OuterEnumInteger::NMINUS_1}) # OuterObjectWithEnumProperty | Input enum (int) as post body
 
 begin
   
diff --git a/samples/client/petstore/ruby/lib/petstore/models/outer_enum_integer.rb b/samples/client/petstore/ruby/lib/petstore/models/outer_enum_integer.rb
index e26193c5a48f..9373d42c5ccd 100644
--- a/samples/client/petstore/ruby/lib/petstore/models/outer_enum_integer.rb
+++ b/samples/client/petstore/ruby/lib/petstore/models/outer_enum_integer.rb
@@ -15,12 +15,13 @@
 
 module Petstore
   class OuterEnumInteger
+    NMINUS_1 = -1.freeze
     N0 = 0.freeze
     N1 = 1.freeze
     N2 = 2.freeze
 
     def self.all_vars
-      @all_vars ||= [N0, N1, N2].freeze
+      @all_vars ||= [NMINUS_1, N0, N1, N2].freeze
     end
 
     # Builds the enum from string