Fix message

src/main/java/com/networknt/schema/MessageSourceValidationMessage.java

@@ -21,6 +21,9 @@
 
 import com.networknt.schema.i18n.MessageSource;
 
+/**
+ * MessageSourceValidationMessage.
+ */
 public class MessageSourceValidationMessage {
 
     public static Builder builder(MessageSource messageSource, Map<String, String> errorMessage,
@@ -66,7 +69,9 @@ public ValidationMessage build() {
                         messagePattern = specificMessagePattern;
                     }
                 }
-                this.message = messagePattern;
+                if (messagePattern != null && !"".equals(messagePattern)) {
+                    this.message = messagePattern;
+                }
             }
 
             // Default to message source formatter

src/test/java/com/networknt/schema/MessageTest.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2024 the original author or authors.
+ *
+ * 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.networknt.schema;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Collections;
+import java.util.Set;
+
+import org.junit.jupiter.api.Test;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.networknt.schema.SpecVersion.VersionFlag;
+
+/**
+ * Test for messages.
+ */
+public class MessageTest {
+    public static class EqualsValidator extends BaseJsonValidator {
+        private static ErrorMessageType ERROR_MESSAGE_TYPE = new ErrorMessageType() {
+            @Override
+            public String getErrorCode() {
+                return "equals";
+            }
+        };
+
+        private final String value;
+
+        public EqualsValidator(SchemaLocation schemaLocation, JsonNodePath evaluationPath, JsonNode schemaNode,
+                JsonSchema parentSchema, Keyword keyword,
+                ValidationContext validationContext, boolean suppressSubSchemaRetrieval) {
+            super(schemaLocation, evaluationPath, schemaNode, parentSchema, ERROR_MESSAGE_TYPE, keyword, validationContext,
+                    suppressSubSchemaRetrieval);
+            this.value = schemaNode.textValue();
+        }
+
+        @Override
+        public Set<ValidationMessage> validate(ExecutionContext executionContext, JsonNode node, JsonNode rootNode,
+                JsonNodePath instanceLocation) {
+            if (!node.asText().equals(value)) {
+                return Collections
+                        .singleton(message().message("{0}: must be equal to ''{1}''")
+                                .arguments(value)
+                                .instanceLocation(instanceLocation).instanceNode(node).build());
+            };
+            return Collections.emptySet();
+        }
+    }
+
+    public static class EqualsKeyword implements Keyword {
+
+        @Override
+        public String getValue() {
+            return "equals";
+        }
+
+        @Override
+        public JsonValidator newValidator(SchemaLocation schemaLocation, JsonNodePath evaluationPath,
+                JsonNode schemaNode, JsonSchema parentSchema, ValidationContext validationContext)
+                throws JsonSchemaException, Exception {
+            return new EqualsValidator(schemaLocation, evaluationPath, schemaNode, parentSchema, this, validationContext, false);
+        }
+    }
+
+    @Test
+    void message() {
+        JsonMetaSchema metaSchema = JsonMetaSchema.builder(JsonMetaSchema.getV202012().getUri(), JsonMetaSchema.getV202012())
+                .addKeyword(new EqualsKeyword()).build();
+        JsonSchemaFactory factory = JsonSchemaFactory.getInstance(VersionFlag.V202012, builder -> builder.addMetaSchema(metaSchema));
+        String schemaData = "{\r\n"
+                + "  \"type\": \"string\",\r\n"
+                + "  \"equals\": \"helloworld\"\r\n"
+                + "}";
+        JsonSchema schema = factory.getSchema(schemaData);
+        Set<ValidationMessage> messages = schema.validate("\"helloworlda\"", InputFormat.JSON);
+        assertEquals(1, messages.size());
+        assertEquals("$: must be equal to 'helloworld'", messages.iterator().next().getMessage());
+
+        messages = schema.validate("\"helloworld\"", InputFormat.JSON);
+        assertEquals(0, messages.size());
+    }
+}