removing deprecated junit methods used in tests

Author: vishwakarma

src/test/java/com/flipkart/zjsonpatch/AbstractTest.java

@@ -30,8 +30,8 @@
 
 import static org.hamcrest.core.IsInstanceOf.instanceOf;
 import static org.hamcrest.core.StringContains.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
 import static org.junit.Assert.fail;
 
 @RunWith(Parameterized.class)

src/test/java/com/flipkart/zjsonpatch/ApiTest.java

@@ -25,7 +25,7 @@
 import java.util.EnumSet;
 
 import static org.hamcrest.CoreMatchers.is;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertTrue;
 
 /**
@@ -107,7 +107,7 @@ public void validatingAPatchWithAnInvalidOperationShouldThrowAnException() throw
         JsonPatch.validate(invalid);
     }
 
-    private static ObjectMapper objectMapper = new ObjectMapper();
+    private static final ObjectMapper objectMapper = new ObjectMapper();
 
     private static JsonNode readTree(String jsonString) throws IOException {
         return objectMapper.readTree(jsonString);

src/test/java/com/flipkart/zjsonpatch/CompatibilityTest.java

@@ -26,7 +26,7 @@
 
 import static com.flipkart.zjsonpatch.CompatibilityFlags.*;
 import static org.hamcrest.core.IsEqual.equalTo;
-import static org.junit.Assert.assertThat;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 public class CompatibilityTest {
 

src/test/java/com/flipkart/zjsonpatch/JsonDiffTest2.java

@@ -26,21 +26,24 @@
 
 import java.io.IOException;
 import java.io.InputStream;
+import java.nio.charset.StandardCharsets;
 
 import static org.hamcrest.core.IsEqual.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
 
 /**
  * @author ctranxuan (streamdata.io).
  */
 public class JsonDiffTest2 {
-    private static ObjectMapper objectMapper = new ObjectMapper();
+    private static final ObjectMapper objectMapper = new ObjectMapper();
     private static ArrayNode jsonNode;
 
     @BeforeClass
     public static void beforeClass() throws IOException {
         String path = "/testdata/diff.json";
         InputStream resourceAsStream = JsonDiffTest.class.getResourceAsStream(path);
-        String testData = IOUtils.toString(resourceAsStream, "UTF-8");
+        Assert.assertNotNull(resourceAsStream);
+        String testData = IOUtils.toString(resourceAsStream, StandardCharsets.UTF_8);
         jsonNode = (ArrayNode) objectMapper.readTree(testData);
     }
 
@@ -54,7 +57,7 @@ public void testPatchAppliedCleanly() {
 
             JsonNode secondPrime = JsonPatch.apply(patch, first);
 
-            Assert.assertThat(message, secondPrime, equalTo(second));
+            assertThat(message, secondPrime, equalTo(second));
         }
 
     }

src/test/java/com/flipkart/zjsonpatch/MoveOperationTest.java

@@ -25,8 +25,7 @@
 import java.util.Collection;
 
 import static org.hamcrest.CoreMatchers.equalTo;
-import static org.junit.Assert.assertThat;
-
+import static org.hamcrest.MatcherAssert.assertThat;
 /**
  * @author ctranxuan (streamdata.io).
  */