isEmpty should return true if there is no optional null field

README.md

@@ -10,7 +10,7 @@ This generates creates Java classes using [Project Lombok](https://projectlombok
 
 * Generates concise POJOs using [Project Lombok](https://projectlombok.org/)
 * Generates POJOs without dependencies on JSON serialization frameworks
-* TODO: Models are generated with convenient methods for checking missing required fields and read-only fields with values and to copy between objects
+* Models are generated with convenient methods for checking missing required fields and read-only fields with values and to copy between objects
 * Implements type polymorphism with `oneOf`-types, even supporting multiple inheritance for classes that are included in multiple `oneOf`-types
 * Implements inheritance with `allOf`-types, including multiple levels of inheritance
 * TODO: Generates client code using HttpURLConnection for HTTP and JSONB for JSON deserialization

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/AddMessageToConversationDeltaDto.java

@@ -14,7 +14,7 @@ public final class AddMessageToConversationDeltaDto implements DeltaDto {
     private ConversationMessageDto message = new ConversationMessageDto();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public AddMessageToConversationDeltaDto putAll(AddMessageToConversationDeltaDto o) {

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/ChangeTrackedDto.java

@@ -12,7 +12,7 @@ public sealed class ChangeTrackedDto implements ChangeTrackedInterface permits C
     private OffsetDateTime updatedAt;
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     @Override

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/CommandToServerDto.java

@@ -14,7 +14,7 @@ public sealed class CommandToServerDto implements MessageToServerDto permits Eve
     private DeltaDto delta;
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public CommandToServerDto putAll(CommandToServerDto o) {

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/CreateConversationDeltaDto.java

@@ -13,7 +13,7 @@ public final class CreateConversationDeltaDto implements DeltaDto {
     private ConversationInfoDto info = new ConversationInfoDto();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public CreateConversationDeltaDto putAll(CreateConversationDeltaDto o) {

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/SnapshotSetDto.java

@@ -10,7 +10,7 @@ public final class SnapshotSetDto implements MessageFromServerDto {
     private List<ConversationSnapshotDto> conversations = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public SnapshotSetDto putAll(SnapshotSetDto o) {

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/SubscribeRequestDto.java

@@ -12,7 +12,7 @@ public final class SubscribeRequestDto implements RequestToServerDto {
     private UUID clientId;
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public SubscribeRequestDto putAll(SubscribeRequestDto o) {

snapshotTests/snapshot/conversations/src/main/java/io/github/jhannes/openapi/conversations/model/UpdateConversationDeltaDto.java

@@ -13,7 +13,7 @@ public final class UpdateConversationDeltaDto implements DeltaDto {
     private ConversationInfoDto info = new ConversationInfoDto();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public UpdateConversationDeltaDto putAll(UpdateConversationDeltaDto o) {

snapshotTests/snapshot/geojson/src/main/java/io/github/jhannes/openapi/geojson/model/GeometryCollectionDto.java

@@ -14,7 +14,7 @@ public final class GeometryCollectionDto {
     private List<GeometryDto> geometries = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public GeometryCollectionDto putAll(GeometryCollectionDto o) {

snapshotTests/snapshot/geojson/src/main/java/io/github/jhannes/openapi/geojson/model/LineStringDto.java

@@ -11,7 +11,7 @@ public final class LineStringDto implements GeometryDto {
     private List<List<Double>> coordinates = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public LineStringDto putAll(LineStringDto o) {

snapshotTests/snapshot/geojson/src/main/java/io/github/jhannes/openapi/geojson/model/PointDto.java

@@ -14,7 +14,7 @@ public final class PointDto implements GeometryDto {
     private List<Double> coordinates = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public PointDto putAll(PointDto o) {

snapshotTests/snapshot/geojson/src/main/java/io/github/jhannes/openapi/geojson/model/PolygonDto.java

@@ -11,7 +11,7 @@ public final class PolygonDto implements GeometryDto {
     private List<List<List<Double>>> coordinates = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public PolygonDto putAll(PolygonDto o) {

snapshotTests/snapshot/infectionTracker/src/main/java/io/github/jhannes/openapi/infectionTracker/model/InfectionDto.java

@@ -13,7 +13,7 @@ public final class InfectionDto {
     private List<ExposureDto> registeredExposures = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public InfectionDto putAll(InfectionDto o) {

snapshotTests/snapshot/openid-configuration/src/main/java/io/github/jhannes/openapi/openid_configuration/model/JwksDocumentDto.java

@@ -10,7 +10,7 @@ public final class JwksDocumentDto {
     private List<JwksKeyDto> keys = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public JwksDocumentDto putAll(JwksDocumentDto o) {

snapshotTests/snapshot/openid-configuration/src/main/java/io/github/jhannes/openapi/openid_configuration/model/OauthErrorDto.java

@@ -31,7 +31,7 @@ public String toString() {
     private String error_description;
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public OauthErrorDto putAll(OauthErrorDto o) {

snapshotTests/snapshot/poly/src/main/java/io/github/jhannes/openapi/poly/model/GeneralErrorDto.java

@@ -11,7 +11,7 @@ public final class GeneralErrorDto implements CreationErrorDto, UpdateErrorDto {
     private String description;
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public GeneralErrorDto putAll(GeneralErrorDto o) {

snapshotTests/snapshot/poly/src/main/java/io/github/jhannes/openapi/poly/model/IllegalEmailAddressErrorDto.java

@@ -12,7 +12,7 @@ public final class IllegalEmailAddressErrorDto implements CreationErrorDto, Upda
     private List<String> validDomains = new ArrayList<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public IllegalEmailAddressErrorDto putAll(IllegalEmailAddressErrorDto o) {

snapshotTests/snapshot/serverHealth/src/main/java/io/github/jhannes/openapi/serverHealth/model/HealthSummaryDto.java

@@ -14,7 +14,7 @@ public final class HealthSummaryDto {
     private Map<String, HealthComponentDto> components = new HashMap<>();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public HealthSummaryDto putAll(HealthSummaryDto o) {

snapshotTests/snapshot/serverHealth/src/main/java/io/github/jhannes/openapi/serverHealth/model/StackTraceInnerDto.java

@@ -14,7 +14,7 @@ public final class StackTraceInnerDto {
     private BigDecimal lineNumber;
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public StackTraceInnerDto putAll(StackTraceInnerDto o) {

snapshotTests/snapshot/websockets/src/main/java/io/github/jhannes/openapi/websockets/model/CreatePersonCommandDto.java

@@ -13,7 +13,7 @@ public final class CreatePersonCommandDto implements WebSocketCommandDto {
     private PersonDto person = new PersonDto();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public CreatePersonCommandDto putAll(CreatePersonCommandDto o) {

snapshotTests/snapshot/websockets/src/main/java/io/github/jhannes/openapi/websockets/model/SubscribeDto.java

@@ -10,7 +10,7 @@ public final class SubscribeDto implements WebSocketRequestDto {
     private String request = "Subscribe";
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public SubscribeDto putAll(SubscribeDto o) {

snapshotTests/snapshot/websockets/src/main/java/io/github/jhannes/openapi/websockets/model/UnsubscribeDto.java

@@ -10,7 +10,7 @@ public final class UnsubscribeDto {
     private String request = "Unsubscribe";
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public UnsubscribeDto putAll(UnsubscribeDto o) {

snapshotTests/snapshot/websockets/src/main/java/io/github/jhannes/openapi/websockets/model/UpdatePersonCommandDto.java

@@ -13,7 +13,7 @@ public final class UpdatePersonCommandDto implements WebSocketCommandDto {
     private PersonDto person = new PersonDto();
 
     public boolean isEmpty() {
-        return false;
+        return true;
     }
 
     public UpdatePersonCommandDto putAll(UpdatePersonCommandDto o) {

src/main/resources/JavaLombok/modelGeneric.handlebars

@@ -75,7 +75,7 @@ public {{#if children}}sealed{{else}}final{{/if}} class {{classname}}
 {{/interfaceModels}}
         ;
 {{else}}
-        return false;
+        return true;
 {{/if}}
     }