fix: [csharp] JsonConverter anyof (#21137)

Author: david-marconis

modules/openapi-generator/src/main/resources/csharp/libraries/generichost/JsonConverter.mustache

@@ -284,6 +284,7 @@
             {{^vendorExtensions.x-duplicated-data-type}}
             {{#model.discriminator}}
             {{#model.hasDiscriminatorWithNonEmptyMapping}}
+            {{^model.composedSchemas.anyOf}}
             {{#mappedModels}}
             if ({{#lambda.camelcase_sanitize_param}}{{model.classname}}{{/lambda.camelcase_sanitize_param}} != null)
                 return new {{classname}}({{#lambda.joinWithComma}}{{#lambda.camelcase_sanitize_param}}{{model.classname}}{{/lambda.camelcase_sanitize_param}}{{#vendorExtensions.x-is-value-type}}{{^isNullable}}.Value{{/isNullable}}{{/vendorExtensions.x-is-value-type}}  {{#model.composedSchemas.anyOf}}{{#lambda.camelcase_sanitize_param}}{{name}}{{/lambda.camelcase_sanitize_param}}{{#vendorExtensions.x-is-value-type}}{{^isNullable}}.Value{{/isNullable}}{{/vendorExtensions.x-is-value-type}}  {{/model.composedSchemas.anyOf}}{{#allVars}}{{^isDiscriminator}}{{#lambda.camelcase_sanitize_param}}{{name}}{{/lambda.camelcase_sanitize_param}}{{#required}}.Value{{nrt!}}{{^isNullable}}{{#vendorExtensions.x-is-value-type}}.Value{{/vendorExtensions.x-is-value-type}}{{/isNullable}}{{/required}}  {{/isDiscriminator}}{{/allVars}}{{/lambda.joinWithComma}});
@@ -292,6 +293,7 @@
             throw new JsonException();
             {{/-last}}
             {{/mappedModels}}
+            {{/model.composedSchemas.anyOf}}
             {{/model.hasDiscriminatorWithNonEmptyMapping}}
             {{/model.discriminator}}
             {{^composedSchemas.oneOf}}

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

@@ -33,6 +33,7 @@
 
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.openapitools.codegen.TestUtils.assertFileContains;
+import static org.openapitools.codegen.TestUtils.assertFileNotContains;
 
 public class CSharpClientCodegenTest {
 
@@ -181,4 +182,33 @@ public void testEnumDiscriminatorDefaultValueIsNotString() throws IOException {
             assertFileContains(file.toPath(), expectedContent);
         }
     }
+
+    @Test
+    public void testAnyOfDiscriminatorCreatesCompilableCode() throws IOException {
+        File output = Files.createTempDirectory("test").toFile().getCanonicalFile();
+        output.deleteOnExit();
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec(
+            "src/test/resources/3_0/anyOfDiscriminatorSimple.yaml");
+        final DefaultGenerator defaultGenerator = new DefaultGenerator();
+        final ClientOptInput clientOptInput = new ClientOptInput();
+        clientOptInput.openAPI(openAPI);
+        CSharpClientCodegen cSharpClientCodegen = new CSharpClientCodegen();
+        cSharpClientCodegen.setLibrary("generichost");
+        cSharpClientCodegen.setOutputDir(output.getAbsolutePath());
+        cSharpClientCodegen.setAutosetConstants(true);
+        clientOptInput.config(cSharpClientCodegen);
+        defaultGenerator.opts(clientOptInput);
+
+        Map<String, File> files = defaultGenerator.generate().stream()
+            .collect(Collectors.toMap(File::getPath, Function.identity()));
+
+        String modelName = "FruitAnyOfDisc";
+        File file = files.get(Paths
+            .get(output.getAbsolutePath(), "src", "Org.OpenAPITools", "Model", modelName + ".cs")
+            .toString()
+        );
+        assertNotNull(file, "Could not find file for model: " + modelName);
+        // Should not contain this as the constructor will have two parameters instead of one
+        assertFileNotContains(file.toPath(), "return new FruitAnyOfDisc(appleAnyOfDisc);");
+    }
 }

modules/openapi-generator/src/test/resources/3_0/anyOfDiscriminatorSimple.yaml

@@ -0,0 +1,36 @@
+openapi: 3.0.1
+info:
+   title: fruity
+   version: 0.0.1
+paths:
+   /:
+      get:
+         responses:
+            '200':
+               description: desc
+               content:
+                  application/json:
+                     schema:
+                        $ref: '#/components/schemas/FruitAnyOfDisc'
+components:
+   schemas:
+    FruitAnyOfDisc:
+      anyOf:
+        - $ref: '#/components/schemas/AppleAnyOfDisc'
+        - $ref: '#/components/schemas/BananaAnyOfDisc'
+      discriminator:
+        propertyName: fruitType
+    AppleAnyOfDisc:
+      type: object
+      required:
+        - fruitType
+      properties:
+        fruitType:
+          type: string
+    BananaAnyOfDisc:
+      type: object
+      required:
+        - fruitType
+      properties:
+        fruitType:
+          type: string