Avoid NullPointerException describing null value (#172)

Signed-off-by: Michael Edgar <[email protected]>

Author: MikeEdgar

src/main/java/org/skyscreamer/jsonassert/JSONCompareResult.java

@@ -245,7 +245,7 @@ private static String describe(Object value) {
         } else if (value instanceof JSONObject) {
             return "a JSON object";
         } else {
-            return value.toString();
+            return String.valueOf(value);
         }
     }
 

src/main/java/org/skyscreamer/jsonassert/comparator/DefaultComparator.java

@@ -50,10 +50,9 @@ public void compareValues(String prefix, Object expectedValue, Object actualValu
         if (expectedValue == actualValue) {
             return;
         }
-        if ((expectedValue == null && actualValue != null) || (expectedValue != null && actualValue == null)) {
+        if (expectedValue == null || actualValue == null) {
             result.fail(prefix, expectedValue, actualValue);
-        }
-        if (areNumbers(expectedValue, actualValue)) {
+        } else if (areNumbers(expectedValue, actualValue)) {
             if (areNotSameDoubles(expectedValue, actualValue)) {
                 result.fail(prefix, expectedValue, actualValue);
             }

src/test/java/org/skyscreamer/jsonassert/JSONCompareTest.java

@@ -21,6 +21,7 @@
 import static org.skyscreamer.jsonassert.JSONCompare.compareJSON;
 import static org.skyscreamer.jsonassert.JSONCompareMode.LENIENT;
 import static org.skyscreamer.jsonassert.JSONCompareMode.NON_EXTENSIBLE;
+import static org.skyscreamer.jsonassert.JSONCompareMode.STRICT;
 
 import org.hamcrest.Description;
 import org.hamcrest.Matcher;
@@ -158,6 +159,32 @@ public void reportsUnmatchedJSONArrayWhereExpectedContainsJSONObjectWithUniqueKe
         assertThat(result, failsWithMessage(equalTo("[0] Could not find match for element {\"id\":3}")));
     }
 
+    @Test
+    public void reportsUnmatchedJSONArrayWhereExpectedContainsNonnullIntegerButActualContainsNullElement() throws JSONException {
+        JSONCompareResult result = compareJSON("[ 3 ]", "[ null ]", LENIENT);
+        assertThat(result, failsWithMessage(equalTo("[]\nExpected: 3\n     but none found\n ; " +
+                "[]\nUnexpected: null\n")));
+    }
+
+    @Test
+    public void reportsUnmatchedJSONArrayWhereExpectedContainsNullElementButActualContainsNonnullInteger() throws JSONException {
+        JSONCompareResult result = compareJSON("[ null ]", "[ 3 ]", LENIENT);
+        assertThat(result, failsWithMessage(equalTo("[]\nExpected: null\n     but none found\n ; " +
+                "[]\nUnexpected: 3\n")));
+    }
+
+    @Test
+    public void reportsStrictUnmatchedJSONArrayWhereExpectedContainsNonnullIntegerButActualContainsNullElement() throws JSONException {
+        JSONCompareResult result = compareJSON("[ 3 ]", "[ null ]", STRICT);
+        assertThat(result, failsWithMessage(equalTo("[0]\nExpected: 3\n     got: null\n")));
+    }
+
+    @Test
+    public void reportsStrictUnmatchedJSONArrayWhereExpectedContainsNullButActualContainsNonnullInteger() throws JSONException {
+        JSONCompareResult result = compareJSON("[ null ]", "[ 3 ]", STRICT);
+        assertThat(result, failsWithMessage(equalTo("[0]\nExpected: null\n     got: 3\n")));
+    }
+
     private Matcher<JSONCompareResult> failsWithMessage(final Matcher<String> expectedMessage) {
         return new TypeSafeMatcher<JSONCompareResult>() {
             @Override