diff --git a/lib/utils/objects.js b/lib/utils/objects.js
--- a/lib/utils/objects.js
+++ b/lib/utils/objects.js
@@ -2,7 +2,6 @@
 
 import stableStringify from 'fast-json-stable-stringify';
 import invariant from 'invariant';
-import _difference from 'lodash/fp/difference.js';
 import _isEqual from 'lodash/fp/isEqual.js';
 import _isPlainObject from 'lodash/fp/isPlainObject.js';
 import stringHash from 'string-hash';
@@ -101,21 +100,19 @@
   expectedObject: ObjectMap<K, T>,
   message: string,
 ) {
-  const processedObjectKeys = Object.keys(processedObject);
-  const expectedObjectKeys = Object.keys(expectedObject);
-
-  const inProcessedButNotExpected =
-    _difference(processedObjectKeys)(expectedObjectKeys);
-  const inExpectedButNotProcessed =
-    _difference(expectedObjectKeys)(processedObjectKeys);
+  if (_isEqual(processedObject)(expectedObject)) {
+    return;
+  }
+  const dataProcessedButNotExpected = deepDiff(processedObject, expectedObject);
+  const dataExpectedButNotProcessed = deepDiff(expectedObject, processedObject);
 
   invariant(
-    _isEqual(processedObject)(expectedObject),
+    false,
     `${message}: Objects should be equal.` +
-      ` Object keys processed but not expected:` +
-      ` ${inExpectedButNotProcessed.toString()}` +
-      ` Object keys expected but not processed:` +
-      ` ${inProcessedButNotExpected.toString()}`,
+      ` Data processed but not expected:` +
+      ` ${JSON.stringify(dataProcessedButNotExpected)}` +
+      ` Data expected but not processed:` +
+      ` ${JSON.stringify(dataExpectedButNotProcessed)}`,
   );
 }