Issue 13043: Improved handling of recursive schemas (#13109)

* Issue 13043: Improved handling of recursive schemas

Converted Exception to a warning when a Schema is doubly added to the includedSchemas list
Broke recursion in a more reasonable place when generating example values

* Addressed comments from PR

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

@@ -1679,23 +1679,6 @@ public class PythonExperimentalClientCodegen extends AbstractPythonCodegen {
         return null;
     }
 
-    /**
-     * Function to isolate the call to add schemas to the includedSchemas list that will detect when
-     * a schema is added multiple times.
-     * @param includedSchemas List of includedSchemas from toExampleValueRecursive
-     * @param schema the schema to add
-     */
-    private void addSchemaToIncludedSchemaList(List<Schema> includedSchemas, Schema schema) {
-
-        // if the schema is in the list, then throw an exception.
-        // this should never happen
-        if(includedSchemas.contains(schema)) {
-            throw new RuntimeException("Attempted to add a schema to the includedSchemas list twice");
-        }
-
-        includedSchemas.add(schema);
-    }
-
     /***
      * Recursively generates string examples for schemas
      *
@@ -1776,7 +1759,10 @@ public class PythonExperimentalClientCodegen extends AbstractPythonCodegen {
             Boolean hasProperties = (schema.getProperties() != null && !schema.getProperties().isEmpty());
             CodegenDiscriminator disc = createDiscriminator(modelName, schema, openAPI);
             if (ModelUtils.isComposedSchema(schema)) {
-                addSchemaToIncludedSchemaList(includedSchemas, schema);
+                if(includedSchemas.contains(schema)) {
+                    return "";
+                }
+                includedSchemas.add(schema);
                 // complex composed object type schemas not yet handled and the code returns early
                 if (hasProperties) {
                     // what if this composed schema defined properties + allOf?
@@ -1941,7 +1927,10 @@ public class PythonExperimentalClientCodegen extends AbstractPythonCodegen {
             ArraySchema arrayschema = (ArraySchema) schema;
             Schema itemSchema = arrayschema.getItems();
             String itemModelName = getModelName(itemSchema);
-            addSchemaToIncludedSchemaList(includedSchemas, schema);
+            if(includedSchemas.contains(schema)) {
+                return "";
+            }
+            includedSchemas.add(schema);
             String itemExample = toExampleValueRecursive(itemModelName, itemSchema, objExample, indentationLevel + 1, "", exampleLine + 1, includedSchemas);
             if (StringUtils.isEmpty(itemExample) || cycleFound) {
                 return fullPrefix + "[]" + closeChars;
@@ -2018,7 +2007,11 @@ public class PythonExperimentalClientCodegen extends AbstractPythonCodegen {
                     addPropPrefix = ensureQuotes(key) + ": ";
                 }
                 String addPropsModelName = getModelName(addPropsSchema);
-                addSchemaToIncludedSchemaList(includedSchemas, schema);
+                if(includedSchemas.contains(schema)) {
+                    return "";
+                }
+                includedSchemas.add(schema);
+
                 example = fullPrefix + "\n" + toExampleValueRecursive(addPropsModelName, addPropsSchema, addPropsExample, indentationLevel + 1, addPropPrefix, exampleLine + 1, includedSchemas) + ",\n" + closingIndentation + closeChars;
             } else {
                 example = fullPrefix + closeChars;
@@ -2035,14 +2028,18 @@ public class PythonExperimentalClientCodegen extends AbstractPythonCodegen {
     }
 
     private String exampleForObjectModel(Schema schema, String fullPrefix, String closeChars, CodegenProperty discProp, int indentationLevel, int exampleLine, String closingIndentation, List<Schema> includedSchemas) {
+
         Map<String, Schema> requiredAndOptionalProps = schema.getProperties();
         if (requiredAndOptionalProps == null || requiredAndOptionalProps.isEmpty()) {
             return fullPrefix + closeChars;
         }
 
-        String example = fullPrefix + "\n";
+        if(includedSchemas.contains(schema)) {
+            return "";
+        }
+        includedSchemas.add(schema);
 
-        addSchemaToIncludedSchemaList(includedSchemas, schema);
+        String example = fullPrefix + "\n";
 
         for (Map.Entry<String, Schema> entry : requiredAndOptionalProps.entrySet()) {
             String propName = entry.getKey();
@@ -2055,14 +2052,25 @@ public class PythonExperimentalClientCodegen extends AbstractPythonCodegen {
                 propExample = discProp.example;
             } else {
                 propModelName = getModelName(propSchema);
-                propExample = exampleFromStringOrArraySchema(propSchema, null, propName);
+                propExample = exampleFromStringOrArraySchema(
+                        propSchema,
+                        null,
+                        propName);
             }
 
-            example += toExampleValueRecursive(propModelName, propSchema, propExample, indentationLevel + 1, propName + "=", exampleLine + 1, includedSchemas) + ",\n";
+            example += toExampleValueRecursive(propModelName,
+                                               propSchema,
+                                               propExample,
+                                               indentationLevel + 1,
+                                               propName + "=",
+                                               exampleLine + 1,
+                                               includedSchemas) + ",\n";
         }
+
         // TODO handle additionalProperties also
         example += closingIndentation + closeChars;
         return example;
+
     }
 
     private Object exampleFromStringOrArraySchema(Schema sc, Object currentExample, String propName) {

modules/openapi-generator/src/test/java/org/openapitools/codegen/python/PythonExperimentalClientTest.java

@@ -20,6 +20,7 @@ import com.google.common.io.Resources;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
 import io.swagger.v3.oas.models.media.*;
+import java.io.PrintWriter;
 import org.openapitools.codegen.*;
 import org.openapitools.codegen.languages.PythonExperimentalClientCodegen;
 import org.openapitools.codegen.utils.ModelUtils;
@@ -28,6 +29,7 @@ import org.testng.annotations.Test;
 
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import org.testng.reporters.jq.Model;
 
 @SuppressWarnings("static-method")
 public class PythonExperimentalClientTest {
@@ -74,24 +76,42 @@ public class PythonExperimentalClientTest {
         Assert.assertFalse(openAPI.getExtensions().containsValue("x-original-swagger-version"));
     }
 
-    @Test(description = "tests GeoJson Examples")
-    public void testRecursiveGeoJsonExample() throws IOException {
-        final OpenAPI openAPI = TestUtils.parseFlattenSpec("src/test/resources/3_0/issue_13043_recursive_model.yaml");
+    @Test(description = "tests GeoJson Example for GeoJsonGeometry")
+    public void testRecursiveGeoJsonExampleWhenTypeIsGeoJsonGeometry() throws IOException {
+
+        testEndpointExampleValue("/geojson",
+                                 "src/test/resources/3_0/issue_13043_recursive_model.yaml",
+                                 "3_0/issue_13043_recursive_model_expected_value.txt");
+
+
+    }
+
+    @Test(description = "tests GeoJson Example for GeometryCollection")
+    public void testRecursiveGeoJsonExampleWhenTypeIsGeometryCollection() throws IOException {
+
+        testEndpointExampleValue("/geojson_geometry_collection",
+                                 "src/test/resources/3_0/issue_13043_recursive_model.yaml",
+                                 "3_0/issue_13043_geometry_collection_expected_value.txt");
+
+    }
+
+    private void testEndpointExampleValue(String endpoint, String specFilePath, String expectedAnswerPath) throws IOException {
+        final OpenAPI openAPI = TestUtils.parseFlattenSpec(specFilePath);
         final PythonExperimentalClientCodegen codegen = new PythonExperimentalClientCodegen();
         codegen.setOpenAPI(openAPI);
 
-        final Operation operation = openAPI.getPaths().get("/geojson").getPost();
+        final Operation operation = openAPI.getPaths().get(endpoint).getPost();
         Schema schema = ModelUtils.getSchemaFromRequestBody(operation.getRequestBody());
         String exampleValue = codegen.toExampleValue(schema, null);
 
-       // uncomment if you need to regenerate the expected value
-       //        PrintWriter printWriter = new PrintWriter("src/test/resources/3_0/issue_8052_recursive_model_expected_value.txt");
-       //        printWriter.write(exampleValue);
-       //        printWriter.close();
-       //        org.junit.Assert.assertTrue(false);
+        // uncomment if you need to regenerate the expected value
+        //        PrintWriter printWriter = new PrintWriter("src/test/resources/" + expectedAnswerPath);
+        //        printWriter.write(exampleValue);
+        //        printWriter.close();
+        //        org.junit.Assert.assertTrue(false);
 
         String expectedValue = Resources.toString(
-                Resources.getResource("3_0/issue_13043_recursive_model_expected_value.txt"),
+                Resources.getResource(expectedAnswerPath),
                 StandardCharsets.UTF_8);
         expectedValue = expectedValue.replaceAll("\\r\\n", "\n");
         Assert.assertEquals(exampleValue.trim(), expectedValue.trim());

modules/openapi-generator/src/test/resources/3_0/issue_13043_geometry_collection_expected_value.txt

@@ -0,0 +1,4 @@
+GeometryCollection(
+        type="GeometryCollection",
+        geometries=[],
+    )

modules/openapi-generator/src/test/resources/3_0/issue_13043_recursive_model.yaml

@@ -26,6 +26,26 @@ paths:
             schema:
               $ref: '#/components/schemas/GeoJsonGeometry'
       parameters: []
+  /geojson_geometry_collection:
+    post:
+      summary: Add a GeoJson GeometryCollection Object
+      operationId: post-geojson-geometry-collection
+      responses:
+        '201':
+          description: Created
+          content:
+            application/json:
+              schema:
+                type: string
+                description: GeoJson ID
+        '400':
+          description: Bad Request
+      requestBody:
+        content:
+          application/json:
+            schema:
+              $ref: '#/components/schemas/GeometryCollection'
+      parameters: []
 components:
   schemas:
     GeoJsonGeometry: