fix: Account for indeterminate Map ordering in unit tests (#274)

Author: kaiyaok2

sdk1/src/test/java/com/amazonaws/services/dynamodbv2/datamodeling/encryption/DynamoDBEncryptorTest.java

@@ -49,6 +49,7 @@
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
 import javax.crypto.KeyGenerator;
@@ -198,15 +199,16 @@ public void ensureEncryptedAttributesUnmodified() throws GeneralSecurityExceptio
     Map<String, AttributeValue> encryptedAttributes =
         encryptor.encryptAllFieldsExcept(
             Collections.unmodifiableMap(attribs), context, "hashKey", "rangeKey", "version");
-    String encryptedString = encryptedAttributes.toString();
+    // Using TreeMap before casting to string to avoid nondeterministic key orders.
+    String encryptedString = new TreeMap<>(encryptedAttributes).toString();
     encryptor.decryptAllFieldsExcept(
         Collections.unmodifiableMap(encryptedAttributes),
         context,
         "hashKey",
         "rangeKey",
         "version");
 
-    assertEquals(encryptedString, encryptedAttributes.toString());
+    assertEquals(encryptedString, new TreeMap<>(encryptedAttributes).toString());
   }
 
   @Test(expectedExceptions = SignatureException.class)

sdk1/src/test/java/com/amazonaws/services/dynamodbv2/datamodeling/internal/AttributeValueMarshallerTest.java

@@ -266,9 +266,13 @@ public void testSimpleMapWithNull() {
       marshall(av);
       Assert.fail("Unexpected success");
     } catch (final NullPointerException npe) {
-      Assert.assertEquals(
-          "Encountered null map value for key NullKeyValue while marshalling attribute value {M: {KeyValue={S: ValueValue,}, NullKeyValue=null},}",
-          npe.getMessage());
+      // Map entries may permute under nondeterministic Java API
+      String npeMessage = npe.getMessage();
+      String common =
+          "Encountered null map value for key NullKeyValue while marshalling attribute value ";
+      String case1 = common + "{M: {KeyValue={S: ValueValue,}, NullKeyValue=null},}";
+      String case2 = common + "{M: {NullKeyValue=null, KeyValue={S: ValueValue,}},}";
+      Assert.assertTrue(case1.equals(npeMessage) || case2.equals(npeMessage));
     }
   }