feat: [OpenAPI] oneOf with a Tensor (n-Dimensional array)

datamodel/openapi/openapi-api-sample/src/main/java/com/sap/cloud/sdk/datamodel/openapi/sample/model/OneOfWithMatrix.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2025 SAP SE or an SAP affiliate company. All rights reserved.
+ */
+
+/*
+ * SodaStore API
+ * API for managing soda products and orders in SodaStore.
+ *
+ *
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package com.sap.cloud.sdk.datamodel.openapi.sample.model;
+
+import java.util.List;
+
+import javax.annotation.Nonnull;
+
+/**
+ * OneOfWithMatrix
+ */
+public interface OneOfWithMatrix
+{
+    /**
+     * Helper class to create a Integer that implements {@link OneOfWithMatrix}.
+     */
+    record InnerInteger(@com.fasterxml.jackson.annotation.JsonValue @Nonnull Integer value) implements OneOfWithMatrix {}
+
+    /**
+     * Creator to enable deserialization of a Integer.
+     *
+     * @param val
+     *            the value to use
+     * @return a new instance of {@link InnerInteger}.
+     */
+    @com.fasterxml.jackson.annotation.JsonCreator
+    @Nonnull
+    static InnerInteger create( @Nonnull final Integer val )
+    {
+        return new InnerInteger(val);
+    }
+
+    /**
+    * Helper class to create {@code List<List<Integer>> } that implements {@link OneOfWithMatrix}.
+    */
+    record InnerIntegers2D(@com.fasterxml.jackson.annotation.JsonValue @Nonnull List<List<Integer>> values) implements OneOfWithMatrix {}
+
+    /**
+     * Creator to enable deserialization of {@code List<List<Integer>> }.
+     *
+     * @param val
+     *            the value to use
+     * @return a new instance of {@link InnerIntegers2D}.
+     */
+    @com.fasterxml.jackson.annotation.JsonCreator
+    @Nonnull
+    static InnerIntegers2D create2DList( @Nonnull final List<List<Integer>> val )
+    {
+        return new InnerIntegers2D(val);
+    }
+
+}

datamodel/openapi/openapi-api-sample/src/main/java/com/sap/cloud/sdk/datamodel/openapi/sample/model/OneOfWithMatrixAndArray.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2025 SAP SE or an SAP affiliate company. All rights reserved.
+ */
+
+/*
+ * SodaStore API
+ * API for managing soda products and orders in SodaStore.
+ *
+ *
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package com.sap.cloud.sdk.datamodel.openapi.sample.model;
+
+import java.util.List;
+
+import javax.annotation.Nonnull;
+
+/**
+ * OneOfWithMatrixAndArray
+ */
+public interface OneOfWithMatrixAndArray
+{
+    /**
+    * Helper class to create a list of Integer that implements {@link OneOfWithMatrixAndArray}.
+    */
+    record InnerIntegers(@com.fasterxml.jackson.annotation.JsonValue @Nonnull List<Integer> values) implements OneOfWithMatrixAndArray {}
+
+    /**
+     * Creator to enable deserialization of a list of Integer.
+     *
+     * @param val
+     *            the value to use
+     * @return a new instance of {@link InnerIntegers}.
+     */
+    @com.fasterxml.jackson.annotation.JsonCreator
+    @Nonnull
+    static InnerIntegers create( @Nonnull final List<Integer> val )
+    {
+        return new InnerIntegers(val);
+    }
+
+    /**
+    * Helper class to create {@code List<List<Integer>> } that implements {@link OneOfWithMatrixAndArray}.
+    */
+    record InnerIntegers2D(@com.fasterxml.jackson.annotation.JsonValue @Nonnull List<List<Integer>> values) implements OneOfWithMatrixAndArray {}
+
+    /**
+     * Creator to enable deserialization of {@code List<List<Integer>> }.
+     *
+     * @param val
+     *            the value to use
+     * @return a new instance of {@link InnerIntegers2D}.
+     */
+    @com.fasterxml.jackson.annotation.JsonCreator
+    @Nonnull
+    static InnerIntegers2D create2DList( @Nonnull final List<List<Integer>> val )
+    {
+        return new InnerIntegers2D(val);
+    }
+
+}

datamodel/openapi/openapi-api-sample/src/main/resources/sodastore.yaml

@@ -117,6 +117,24 @@ components:
         mapping:
           disc_foo: '#/components/schemas/Foo'
           disc_bar: '#/components/schemas/Bar'
+    OneOfWithMatrix:
+      oneOf:
+        - type: integer
+        - type: array
+          items:
+            type: array
+            items:
+              type: integer
+    OneOfWithMatrixAndArray:
+      oneOf:
+        - type: array
+          items:
+            type: integer
+        - type: array
+          items:
+            type: array
+            items:
+              type: integer
     Foo:
       type: object
       properties:

datamodel/openapi/openapi-api-sample/src/test/java/com/sap/cloud/sdk/datamodel/openapi/sample/api/OneOfDeserializationTest.java

@@ -3,6 +3,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 
+import java.util.List;
 import java.util.stream.Stream;
 
 import javax.annotation.Nonnull;
@@ -17,6 +18,7 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.exc.InvalidDefinitionException;
 import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
 import com.sap.cloud.sdk.datamodel.openapi.sample.model.AllOf;
 import com.sap.cloud.sdk.datamodel.openapi.sample.model.AnyOf;
@@ -30,6 +32,8 @@
 import com.sap.cloud.sdk.datamodel.openapi.sample.model.OneOfWithDiscriminator;
 import com.sap.cloud.sdk.datamodel.openapi.sample.model.OneOfWithDiscriminatorAndMapping;
 import com.sap.cloud.sdk.datamodel.openapi.sample.model.OneOfWithEnumDiscriminator;
+import com.sap.cloud.sdk.datamodel.openapi.sample.model.OneOfWithMatrix;
+import com.sap.cloud.sdk.datamodel.openapi.sample.model.OneOfWithMatrixAndArray;
 
 class OneOfDeserializationTest
 {
@@ -169,6 +173,28 @@ void oneOfWithNestedArrayOfObjects( Class<?> strategy )
 
     }
 
+    @Test
+    void oneOfWIthMatrixOfObjects()
+        throws JsonProcessingException
+    {
+        var json = """
+            [
+              [1, 2, 3 ],
+              [4, 5, 6 ]
+            ]
+            """;
+        var matrix = objectMapper.readValue(json, OneOfWithMatrix.class);
+        assertThat(matrix)
+            .describedAs("Object should be deserialized as InnerIntegers2D")
+            .isInstanceOfSatisfying(
+                OneOfWithMatrix.InnerIntegers2D.class,
+                integers2D -> assertThat(integers2D.values()).isEqualTo(List.of(List.of(1, 2, 3), List.of(4, 5, 6))));
+
+        assertThatThrownBy(() -> objectMapper.readValue(json, OneOfWithMatrixAndArray.class))
+            .hasMessageContaining("Conflicting array-delegate creators")
+            .isInstanceOf(InvalidDefinitionException.class);
+    }
+
     @Test
     void anyOf()
         throws JsonProcessingException

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

@@ -271,16 +271,30 @@ private void useCreatorsForInterfaceSubtypes( @Nonnull final CodegenModel m )
         boolean useCreators = false;
         for( final Set<String> candidates : List.of(m.anyOf, m.oneOf) ) {
             int nonPrimitives = 0;
-            final var candidatesSingle = new HashSet<String>();
-            final var candidatesMultiple = new HashSet<String>();
+            final var singleTypes = new HashSet<String>();
+            final var arrayTypes1D = new HashSet<String>();
+            final var arrayTypesND = new HashSet<Map<String, String>>();
 
             for( final String candidate : candidates ) {
                 if( candidate.startsWith("List<") ) {
-                    final var c1 = candidate.substring(5, candidate.length() - 1);
-                    candidatesMultiple.add(c1);
+                    int depth = 0;
+                    String sub = candidate;
+                    while( sub.startsWith("List<") ) {
+                        sub = sub.substring(5, sub.length() - 1);
+                        depth++;
+                    }
+
+                    final String innerType = sub;
+                    if( depth == 1 ) {
+                        arrayTypes1D.add(innerType);
+                    } else {
+                        arrayTypesND
+                            .add(Map.of("innerType", innerType, "depth", String.valueOf(depth), "fullType", candidate));
+                    }
+
                     useCreators = true;
                 } else {
-                    candidatesSingle.add(candidate);
+                    singleTypes.add(candidate);
                     useCreators |= PRIMITIVES.contains(candidate);
                     if( !PRIMITIVES.contains(candidate) ) {
                         nonPrimitives++;
@@ -293,8 +307,17 @@ private void useCreatorsForInterfaceSubtypes( @Nonnull final CodegenModel m )
                         "Generating interface with mixed multiple non-primitive and primitive sub-types: {}. Deserialization may not work.";
                     log.warn(msg, m.name);
                 }
+                final var numArrayTypes = singleTypes.size() + arrayTypesND.size();
+                if( numArrayTypes > 1 ) {
+                    final var msg =
+                        "Field can be oneOf %d array types. Deserialization may not work as expected."
+                            .formatted(numArrayTypes);
+                    log.warn(msg, m.name);
+                }
+
                 candidates.clear();
-                final var monads = Map.of("single", candidatesSingle, "multiple", candidatesMultiple);
+                final var monads =
+                    Map.of("single", singleTypes, "multiple1D", arrayTypes1D, "multipleND", arrayTypesND);
                 m.vendorExtensions.put("x-monads", monads);
                 m.vendorExtensions.put("x-is-one-of-interface", true); // enforce template usage
             }

datamodel/openapi/openapi-generator/src/main/resources/openapi-generator/mustache-templates/oneof_interface.mustache

@@ -28,7 +28,7 @@ public interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}exte
     static Inner{{.}} create( @Nonnull final {{.}} val) { return new Inner{{.}}(val); }
 
 {{/model.vendorExtensions.x-monads.single}}
-{{#model.vendorExtensions.x-monads.multiple}}
+{{#model.vendorExtensions.x-monads.multiple1D}}
     /**
     * Helper class to create a list of {{.}} that implements {@link {{classname}}}.
     */
@@ -44,5 +44,22 @@ public interface {{classname}} {{#vendorExtensions.x-implements}}{{#-first}}exte
     @Nonnull
     static Inner{{.}}s create( @Nonnull final List<{{.}}> val) { return new Inner{{.}}s(val); }
 
-{{/model.vendorExtensions.x-monads.multiple}}
+{{/model.vendorExtensions.x-monads.multiple1D}}
+{{#model.vendorExtensions.x-monads.multipleND}}
+    /**
+    * Helper class to create {@code {{{fullType}}} } that implements {@link {{classname}}}.
+    */
+    record Inner{{innerType}}s{{depth}}D(@com.fasterxml.jackson.annotation.JsonValue @Nonnull {{{fullType}}} values) implements {{classname}} {}
+
+    /**
+    * Creator to enable deserialization of {@code {{{fullType}}} }.
+    *
+    * @param val the value to use
+    * @return a new instance of {@link Inner{{innerType}}s{{depth}}D}.
+    */
+    @com.fasterxml.jackson.annotation.JsonCreator
+    @Nonnull
+    static Inner{{innerType}}s{{depth}}D create{{depth}}DList( @Nonnull final {{{fullType}}} val) { return new Inner{{innerType}}s{{depth}}D(val); }
+
+{{/model.vendorExtensions.x-monads.multipleND}}
 }