initial implementation of StringSchema#describePropertiesTo()

Author: erosb

core/src/main/java/org/everit/json/schema/StringSchema.java

@@ -15,6 +15,8 @@
  */
 package org.everit.json.schema;
 
+import org.everit.json.schema.internal.JSONPrinter;
+
 import java.util.*;
 import java.util.regex.Pattern;
 
@@ -203,4 +205,14 @@ public int hashCode() {
     protected boolean canEqual(Object other) {
         return other instanceof StringSchema;
     }
+
+    @Override
+    void describePropertiesTo(JSONPrinter writer) {
+        if (requiresString) {
+            writer.key("type").value("string");
+        }
+        writer.ifPresent("minLength", minLength);
+        writer.ifPresent("maxLength", maxLength);
+        writer.ifPresent("pattern", pattern);
+    }
 }

core/src/test/java/org/everit/json/schema/StringSchemaTest.java

@@ -17,11 +17,15 @@
 
 import nl.jqno.equalsverifier.EqualsVerifier;
 import nl.jqno.equalsverifier.Warning;
+import org.everit.json.schema.loader.SchemaLoader;
+import org.json.JSONObject;
 import org.junit.Assert;
 import org.junit.Test;
 
 import java.util.Optional;
 
+import static org.junit.Assert.assertTrue;
+
 public class StringSchemaTest {
 
     @Test
@@ -110,4 +114,19 @@ public void equalsVerifier() {
                 .suppress(Warning.STRICT_INHERITANCE)
                 .verify();
     }
+
+    @Test
+    public void toStringTest() {
+        JSONObject rawSchemaJson = ResourceLoader.DEFAULT.readObj("tostring/stringschema.json");
+        String actual = SchemaLoader.load(rawSchemaJson).toString();
+        assertTrue(ObjectComparator.deepEquals(rawSchemaJson, new JSONObject(actual)));
+    }
+
+    @Test
+    public void toStringNoExplicitType() {
+        JSONObject rawSchemaJson = ResourceLoader.DEFAULT.readObj("tostring/stringschema.json");
+        rawSchemaJson.remove("type");
+        String actual = SchemaLoader.load(rawSchemaJson).toString();
+        assertTrue(ObjectComparator.deepEquals(rawSchemaJson, new JSONObject(actual)));
+    }
 }

core/src/test/resources/org/everit/jsonvalidator/tostring/stringschema.json

@@ -0,0 +1,6 @@
+{
+  "type" : "string",
+  "minLength": 0,
+  "maxLength": 10,
+  "pattern": "a.b*c"
+}