Add empty key support into U.toXml(map) and U.fromJson(string).

Author: javadev

src/main/java/com/github/underscore/lodash/U.java

@@ -1673,9 +1673,12 @@ public static void writeJson(Object value, JsonStringBuilder builder) {
 
         public static String unescapeName(final String name) {
             final int length = name.length();
-            if (length == 0) {
+            if (length == 0 || "__EE__EMPTY__EE__".equals(name)) {
                 return "";
             }
+            if ("-__EE__EMPTY__EE__".equals(name)) {
+                return "-";
+            }
             StringBuilder result = new StringBuilder();
             int underlineCount = 0;
             StringBuilder lastChars = new StringBuilder();
@@ -2222,9 +2225,9 @@ public static void writeXml(Object value, String name, XmlStringBuilder builder,
         public static String escapeName(String name) {
             final int length = name.length();
             if (length == 0) {
-                return "";
+                return "__EE__EMPTY__EE__";
             }
-            StringBuilder result = new StringBuilder();
+            final StringBuilder result = new StringBuilder();
             char ch = name.charAt(0);
             if (com.sun.org.apache.xerces.internal.util.XMLChar.isNameStart(ch)) {
                 result.append(ch);

src/test/java/com/github/underscore/lodash/StringTest.java

@@ -1311,8 +1311,8 @@ public void toXmlFromMap() {
         assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<root>\nnull\n</root>", U.toXml((Map) null));
         assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<root>\n  <item>\n"
                 + "  </item>\n</root>", U.toXml(testMap2));
-        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<>1"
-                + "</>", U.toXml(testMap3));
+        assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<__EE__EMPTY__EE__>1"
+                + "</__EE__EMPTY__EE__>", U.toXml(testMap3));
     }
 
     @SuppressWarnings("unchecked")
@@ -1430,6 +1430,19 @@ public void toJsonFromXml6() {
                 U.toJson((Map<String, Object>) U.fromXml(xml)));
     }
 
+    @SuppressWarnings("unchecked")
+    @Test
+    public void toJsonFromXml7() {
+        final String xml = "<__EE__EMPTY__EE__ __EE__EMPTY__EE__=\"1\">\n"
+                + "</__EE__EMPTY__EE__>";
+        assertEquals("{\n"
+                + "  \"\": {\n"
+                + "    \"-\": \"1\"\n"
+                + "  }\n"
+                + "}",
+                U.toJson((Map<String, Object>) U.fromXml(xml)));
+    }
+
     @SuppressWarnings("unchecked")
     @Test
     public void toXmlFromJson() {
@@ -1572,8 +1585,8 @@ public void toXmlFromJson5() {
                 + "  }\n"
                 + "}";
         assertEquals("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
-                + "<>\n"
-                + "</>",
+                + "<__EE__EMPTY__EE__>\n"
+                + "</__EE__EMPTY__EE__>",
                 U.toXml((Map<String, Object>) U.fromJson(json)));
     }