add patternProperties Validation and Test (membrane#1929)

* wip

* fix

* fix

* add missing info

* rm types

* renaming

Author: christiangoerdes

core/src/main/java/com/predic8/membrane/core/openapi/validators/ObjectValidator.java

@@ -24,6 +24,7 @@
 
 import java.io.*;
 import java.util.*;
+import java.util.regex.Pattern;
 
 import static com.predic8.membrane.core.openapi.util.Utils.*;
 import static java.lang.String.*;
@@ -75,6 +76,7 @@ public ValidationErrors validate(ValidationContext ctx, Object obj) {
         ValidationErrors errors = validateRequiredProperties(ctx, node);
         errors.add(validateAddionalProperties(ctx, node));
         errors.add(validateProperties(ctx, node));
+        errors.add(validatePatternProperties(ctx, node));
         errors.add(validateSize(ctx, node));
         errors.add(validateDiscriminator(ctx,node));
         return errors;
@@ -234,11 +236,37 @@ private ValidationErrors validateProperties(ValidationContext ctx, JsonNode node
         return errors;
     }
 
+    private ValidationErrors validatePatternProperties(ValidationContext ctx, JsonNode node) {
+        if(schema.getPatternProperties() == null) {
+            return null;
+        }
+        ValidationErrors errors = new ValidationErrors();
+
+        getPatternPropertiesFromSchema().forEach((regex, propSchema) -> {
+            Pattern pattern = Pattern.compile(regex);
+
+            for (Iterator<String> it = node.fieldNames(); it.hasNext(); ) {
+                String fieldName = it.next();
+                if (pattern.matcher(fieldName).matches()) {
+                    JsonNode childNode = node.get(fieldName);
+                    errors.add(new SchemaValidator(api, propSchema)
+                            .validate(ctx, childNode));
+                }
+            }
+        });
+        return errors;
+    }
+
     @SuppressWarnings({"rawtypes", "unchecked"})
     private Map<String, Schema> getPropertiesFromSchema() {
         return (Map<String, Schema>) schema.getProperties();
     }
 
+    @SuppressWarnings({"rawtypes", "unchecked"})
+    private Map<String, Schema> getPatternPropertiesFromSchema() {
+        return (Map<String, Schema>) schema.getPatternProperties();
+    }
+
     @SuppressWarnings("rawtypes")
     private ValidationErrors validateReadOnlyProperty(ValidationContext ctx, JsonNode node, String propertyName, Schema propertySchema) {
         if (propertySchema.getReadOnly() == null || !propertySchema.getReadOnly())

core/src/test/java/com/predic8/membrane/core/openapi/validators/PatternPropertiesTest.java

@@ -0,0 +1,49 @@
+/* Copyright 2025 predic8 GmbH, www.predic8.com
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License. */
+
+package com.predic8.membrane.core.openapi.validators;
+
+import com.predic8.membrane.core.openapi.model.Request;
+import jakarta.mail.internet.ParseException;
+import org.junit.jupiter.api.Test;
+
+import static com.predic8.membrane.core.http.MimeType.APPLICATION_JSON;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class PatternPropertiesTest extends AbstractValidatorTest{
+
+    @Override
+    protected String getOpenAPIFileName() {
+        return "/openapi/specs/pattern-properties.yaml";
+    }
+
+    @Test
+    void invalidRequest() throws ParseException {
+        ValidationErrors errors = validator.validate(Request.post().mediaType(APPLICATION_JSON).path("/test").body("""
+                {"foo": []}
+                """));
+        assertEquals(1,errors.size());
+        assertTrue(errors.toString().contains("Array has 0 items. This is less then minItems of 2."));
+    }
+
+    @Test
+    void validRequest() throws ParseException {
+        ValidationErrors errors = validator.validate(Request.post().mediaType(APPLICATION_JSON).path("/test").body("""
+                {"foo": [1, 2]}
+                """));
+        assertEquals(0,errors.size());
+    }
+
+}

core/src/test/resources/openapi/specs/pattern-properties.yaml

@@ -0,0 +1,25 @@
+openapi: "3.1.0"
+info:
+  title: Pattern Properties API
+  version: '1.0'
+paths:
+  /test:
+    post:
+      requestBody:
+        content:
+          application/json:
+            schema:
+              properties:
+                foo:
+                  type: "array"
+                  maxItems: 3
+                bar:
+                  type: "array"
+              patternProperties:
+                f.o:
+                  minItems: 2
+              additionalProperties:
+                type: "integer"
+      responses:
+        "200":
+          description: "OK"