There was 1 failure:

1) Composer\Test\Json\JsonFileTest::testFormatEmptyArray
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
 '{
-    "test": [
-
-    ],
-    "test2": {
-
-    }
+    "test": [],
+    "test2": {}
 }'

/Users/rdohms/dev/oss/composer/tests/Composer/Test/Json/JsonFileTest.php:235
/Users/rdohms/dev/oss/composer/tests/Composer/Test/Json/JsonFileTest.php:149
/Users/rdohms/.composer/vendor/phpunit/phpunit/src/TextUI/Command.php:179
/Users/rdohms/.composer/vendor/phpunit/phpunit/src/TextUI/Command.php:132