[CSHARP] Fix how the array type is set when using NULLABLE_REFERENCE_TYPES (#22071)

* Fix how the type is calculated for deep inline arrays

* Add list alias objects to petstore specification and regenerate samples

Author: Mattias-Sehlstedt

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

@@ -1628,7 +1628,7 @@ public String getTypeDeclaration(Schema p) {
         Schema<?> target = ModelUtils.isGenerateAliasAsModel() ? p : schema;
         if (ModelUtils.isArraySchema(target)) {
             Schema<?> items = getSchemaItems(schema);
-            return getSchemaType(target) + "<" + getTypeDeclarationForArray(items) + ">";
+            return typeMapping.get("array") + "<" + getTypeDeclarationForArray(items) + ">";
         } else if (ModelUtils.isMapSchema(p)) {
             // Should we also support maps of maps?
             Schema<?> inner = ModelUtils.getAdditionalProperties(p);

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

@@ -368,11 +368,27 @@ public void nullablePropertyWithoutNullableReferenceTypesTest() {
     public void nullablePropertyWithNullableReferenceTypesTest() {
         final Schema model = new Schema()
                 .description("a sample model")
-                .addProperties("id", new IntegerSchema().format(SchemaTypeUtil.INTEGER64_FORMAT).nullable(true))
+                .addProperties("id", new IntegerSchema().format(SchemaTypeUtil.INTEGER64_FORMAT)
+                        .nullable(true))
                 .addProperties("urls", new ArraySchema()
-                        .items(new StringSchema()).nullable(true))
+                        .items(new StringSchema())
+                        .nullable(true))
                 .addProperties("name", new StringSchema().nullable(true))
-                .addProperties("subObject", new Schema().addProperties("name", new StringSchema()).nullable(true))
+                .addProperties("subObject", new Schema().addProperties("name", new StringSchema())
+                        .nullable(true))
+                .addProperties("deepNullableAliasArray", new ArraySchema()
+                        .items(new ArraySchema()
+                                .items(new StringSchema()
+                                        .nullable(true))
+                                .nullable(true))
+                        .nullable(true))
+                .addProperties("deepAliasArray", new ArraySchema()
+                        .items(new ArraySchema()
+                                .items(new StringSchema())))
+                .addProperties("deepIntermediateNullableAliasArray", new ArraySchema()
+                        .items(new ArraySchema()
+                                .items(new StringSchema())
+                                .nullable(true)))
                 .addRequiredItem("id");
         final DefaultCodegen codegen = new AspNetServerCodegen();
         codegen.processOpts();
@@ -385,7 +401,7 @@ public void nullablePropertyWithNullableReferenceTypesTest() {
         Assert.assertEquals(cm.name, "sample");
         Assert.assertEquals(cm.classname, "Sample");
         Assert.assertEquals(cm.description, "a sample model");
-        Assert.assertEquals(cm.vars.size(), 4);
+        Assert.assertEquals(cm.vars.size(), 7);
 
         final CodegenProperty property1 = cm.vars.get(0);
         Assert.assertEquals(property1.baseName, "id");
@@ -398,7 +414,7 @@ public void nullablePropertyWithNullableReferenceTypesTest() {
 
         final CodegenProperty property2 = cm.vars.get(1);
         Assert.assertEquals(property2.baseName, "urls");
-        Assert.assertEquals(property2.dataType, "List?<string>");
+        Assert.assertEquals(property2.dataType, "List<string>");
         Assert.assertEquals(property2.name, "Urls");
         Assert.assertNull(property2.defaultValue);
         Assert.assertEquals(property2.baseType, "List?");
@@ -424,6 +440,33 @@ public void nullablePropertyWithNullableReferenceTypesTest() {
         Assert.assertEquals(property4.baseType, "Object?");
         Assert.assertFalse(property4.required);
         Assert.assertFalse(property4.isPrimitiveType);
+
+        final CodegenProperty property5 = cm.vars.get(4);
+        Assert.assertEquals(property5.baseName, "deepNullableAliasArray");
+        Assert.assertEquals(property5.dataType, "List<List<string?>>");
+        Assert.assertEquals(property5.name, "DeepNullableAliasArray");
+        Assert.assertNull(property5.defaultValue);
+        Assert.assertEquals(property5.baseType, "List?");
+        Assert.assertEquals(property5.containerType, "array");
+        Assert.assertFalse(property5.required);
+        Assert.assertFalse(property5.isPrimitiveType);
+        Assert.assertTrue(property5.isContainer);
+
+        final CodegenProperty property6 = cm.vars.get(5);
+        Assert.assertEquals(property6.baseName, "deepAliasArray");
+        Assert.assertEquals(property6.dataType, "List<List<string>>");
+        Assert.assertEquals(property6.name, "DeepAliasArray");
+        Assert.assertEquals(property6.baseType, "List");
+        Assert.assertEquals(property6.containerType, "array");
+        Assert.assertTrue(property6.isContainer);
+
+        final CodegenProperty property7 = cm.vars.get(6);
+        Assert.assertEquals(property7.baseName, "deepIntermediateNullableAliasArray");
+        Assert.assertEquals(property7.dataType, "List<List<string>>");
+        Assert.assertEquals(property7.name, "DeepIntermediateNullableAliasArray");
+        Assert.assertEquals(property7.baseType, "List");
+        Assert.assertEquals(property7.containerType, "array");
+        Assert.assertTrue(property7.isContainer);
     }
 
     @Test(description = "convert a model with list property")

modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml

@@ -2935,6 +2935,16 @@ components:
           description: list of named parameters for current message
           additionalProperties:
             type: string
+    ListAlias:
+      type: array
+      items:
+        type: string
+    DeepListAlias:
+      type: array
+      items:
+        type: array
+        items:
+          type: string
     TestResult:
       type: object
       allOf:

samples/client/petstore/csharp/generichost/net4.7/FormModels/api/openapi.yaml

@@ -2687,6 +2687,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"

samples/client/petstore/csharp/generichost/net4.7/Petstore/api/openapi.yaml

@@ -2868,6 +2868,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"

samples/client/petstore/csharp/generichost/net4.8/FormModels/api/openapi.yaml

@@ -2687,6 +2687,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"

samples/client/petstore/csharp/generichost/net4.8/Petstore/api/openapi.yaml

@@ -2868,6 +2868,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"

samples/client/petstore/csharp/generichost/net8/FormModels/api/openapi.yaml

@@ -2687,6 +2687,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"

samples/client/petstore/csharp/generichost/net8/NullReferenceTypes/api/openapi.yaml

@@ -2868,6 +2868,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"

samples/client/petstore/csharp/generichost/net8/Petstore/api/openapi.yaml

@@ -2868,6 +2868,16 @@ components:
           description: list of named parameters for current message
           type: object
       type: object
+    ListAlias:
+      items:
+        type: string
+      type: array
+    DeepListAlias:
+      items:
+        items:
+          type: string
+        type: array
+      type: array
     TestResult:
       allOf:
       - $ref: "#/components/schemas/Result"