More test cases for position information

src/test/java/org/json/junit/JSONTokenerTest.java

@@ -1,6 +1,8 @@
 package org.json.junit;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
 import java.io.BufferedReader;
@@ -121,7 +123,12 @@ public class JSONTokenerTest {
     @Test
     public void testNextBackComboWithNewLines() {
         final String testString = "this is\nA test\r\nWith some different\rNew Lines";
+        //                         ^       ^         ^                    ^
+        // index positions         0       8        16                   36
         final JSONTokener tokener = new JSONTokener(testString);
+        assertEquals(" at 0 [character 1 line 1]", tokener.toString());
+        assertEquals('t',tokener.next());
+        assertEquals(" at 1 [character 2 line 1]", tokener.toString());
         tokener.skipTo('\n');
         assertEquals("skipTo() improperly modifying indexes"," at 7 [character 8 line 1]", tokener.toString());
         assertEquals('\n',tokener.next());
@@ -132,10 +139,12 @@ public class JSONTokenerTest {
         assertEquals(" at 8 [character 0 line 2]", tokener.toString());
         tokener.skipTo('\r');
         assertEquals("skipTo() improperly modifying indexes"," at 14 [character 6 line 2]", tokener.toString());
+        // verify \r\n combo doesn't increment the line twice
         assertEquals('\r', tokener.next());
         assertEquals(" at 15 [character 0 line 3]", tokener.toString());
         assertEquals('\n', tokener.next());
         assertEquals(" at 16 [character 0 line 3]", tokener.toString());
+        // verify stepping back after reading the \n of an \r\n combo doesn't  increment the line incorrectly
         tokener.back();
         assertEquals(" at 15 [character 6 line 2]", tokener.toString());
         assertEquals('\n', tokener.next());
@@ -154,5 +163,39 @@ public class JSONTokenerTest {
         assertEquals(" at 36 [character 0 line 4]", tokener.toString());
         assertEquals('N', tokener.next());
         assertEquals(" at 37 [character 1 line 4]", tokener.toString());
+        
+        // verify we get the same data just walking though, no calls to back
+        final JSONTokener t2 = new JSONTokener(testString);
+        for(int i=0; i<7; i++) {
+            assertTrue(t2.toString().startsWith(" at " + i + " "));
+            assertEquals(testString.charAt(i), t2.next());
+        }
+        assertEquals(" at 7 [character 8 line 1]", t2.toString());
+        assertEquals(testString.charAt(7), t2.next());
+        assertEquals(" at 8 [character 0 line 2]", t2.toString());
+        for(int i=8; i<14; i++) {
+            assertTrue(t2.toString().startsWith(" at " + i + " "));
+            assertEquals(testString.charAt(i), t2.next());
+        }
+        assertEquals(" at 14 [character 6 line 2]", t2.toString());
+        assertEquals('\r', t2.next());
+        assertEquals(" at 15 [character 0 line 3]", t2.toString());
+        assertEquals('\n', t2.next());
+        assertEquals(" at 16 [character 0 line 3]", t2.toString());
+        assertEquals('W', t2.next());
+        assertEquals(" at 17 [character 1 line 3]", t2.toString());
+        for(int i=17; i<37; i++) {
+            assertTrue(t2.toString().startsWith(" at " + i + " "));
+            assertEquals(testString.charAt(i), t2.next());
+        }
+        assertEquals(" at 37 [character 1 line 4]", t2.toString());
+        for(int i=37; i<testString.length(); i++) {
+            assertTrue(t2.toString().startsWith(" at " + i + " "));
+            assertEquals(testString.charAt(i), t2.next());
+        }
+        assertEquals(" at "+ testString.length() +" [character 9 line 4]", t2.toString());
+        // end of the input
+        assertEquals(0, t2.next());
+        assertFalse(t2.more());
    }
 }