Fixing a bug with a 1 character path

json-path/src/main/java/com/jayway/jsonpath/internal/token/TokenStack.java

@@ -25,6 +25,7 @@ public class TokenStack
     protected Map<TokenStackElement, Path> matchedPaths;
 
     private TokenStackElement curr;
+    private Path rootMatch;
 
     public TokenStack(Configuration conf)
     {
@@ -32,6 +33,7 @@ public class TokenStack
         paths = new ArrayList<Path>();
         matchedPaths = new HashMap<TokenStackElement, Path>();
         elements = new Stack<TokenStackElement>();
+        rootMatch = null;
     }
 
     public Stack<TokenStackElement> getStack()
@@ -56,6 +58,16 @@ public class TokenStack
         assert(callback != null);
 
         boolean needsPathCheck = false;
+        if (null == curr && elements.empty()) {
+            // check for $ patterns
+            for (Path path : paths) {
+                if (path.checkForMatch(this)) {
+                    //if (saveMatch) matchedPaths.put(curr, path);
+                    callback.resultFound(path);
+                    rootMatch = path;
+                }
+            }
+        }
         while (parser.nextToken() != null) {
             boolean saveMatch = false;
             switch (parser.getCurrentToken()) {
@@ -90,8 +102,8 @@ public class TokenStack
                 if (curr != null && curr.getType() == TokenType.ARRAY_TOKEN) {
 
                     if (((ArrayToken)curr).getValue() != null &&
-                        matchedPaths.containsKey(curr)) {
-
+                        matchedPaths.containsKey(curr))
+                    {
                         Path match = matchedPaths.remove(curr);
                         callback.resultFoundExit(match);
 
@@ -188,6 +200,11 @@ public class TokenStack
                 needsPathCheck = false;
             }
         }
+
+        if (rootMatch != null && elements.empty()) {
+            callback.resultFoundExit(rootMatch);
+            rootMatch = null;
+        }
     }
 
     public String toString()
@@ -200,7 +217,7 @@ public class TokenStack
             sb.append(elem.toString());
         }
         sb.append(" ");
-        sb.append(elements.peek().getValue());
+        if (!elements.empty()) sb.append(elements.peek().getValue());
         return sb.toString();
     }
 

json-path/src/test/java/com/jayway/jsonpath/JacksonTest.java

@@ -64,6 +64,7 @@ public class JacksonTest extends BaseTest implements EvaluationCallback {
     protected int floatMatch = 0;
     protected Path intPath = null;
     protected int intMatch = 0;
+    protected Path rootPath = null;
 
     @Test
     public void streamingTest() throws Exception {
@@ -76,6 +77,7 @@ public class JacksonTest extends BaseTest implements EvaluationCallback {
             PathCompiler.compile("$..completed_tasks[0:].resources.cpus");
         intPath =
             PathCompiler.compile("$..completed_tasks[0:].resources.mem");
+        rootPath = PathCompiler.compile("$");
         stack = new TokenStack(JACKSON_CONFIGURATION);
 
         recorder = new CallbackRecorder();
@@ -90,9 +92,12 @@ public class JacksonTest extends BaseTest implements EvaluationCallback {
         stack.registerPath(idPath);
         stack.registerPath(floatPath);
         stack.registerPath(intPath);
+        stack.registerPath(rootPath);
         stack.read(factory.createJsonParser(stream), this);
         Thread.sleep(1000);
 
+        assert(recorder.getResults().get(count++).
+               equals(new CallbackRecorder.CallbackEvent(rootPath, false)));
         assert(recorder.getResults().get(count++).
                equals(new CallbackRecorder.CallbackEvent(path, false)));
         assert(recorder.getResults().get(count++).
@@ -598,6 +603,8 @@ public class JacksonTest extends BaseTest implements EvaluationCallback {
                equals(new CallbackRecorder.CallbackEvent(intPath, false)));
         assert(recorder.getResults().get(count++).
                equals(new CallbackRecorder.CallbackEvent(path, true)));
+        assert(recorder.getResults().get(count++).
+               equals(new CallbackRecorder.CallbackEvent(rootPath, true)));
     }
 
     public void resultFound(Path path) {