Neater removeUndef() thanks to @achou11

test/index.js

@@ -62,22 +62,17 @@ then decoding and comparing the two objects - extra values shouldn't be present`
 })
 
 /**
+ * Remove undefined properties (deeply) from an object, by round-tripping to
+ * JSON. Also handles Buffers via JSON.parse reviver
+ *
  * @param {object} obj
  * @return {object}
  * */
 function stripUndef(obj) {
-  // Apologies, if I was not so lazy I would write a deep compare function that
-  // ignores undefined properties, but instead we do it the lazy way and round
-  // trip to JSON in order to remove undefined properties. Properties that are
-  // Buffers won't survive the round trip, so we remove them and add them back.
-  // Messy, but works well enough for tests. Sorry.
-  const { coreSignatures, identitySignature, ...rest } = obj
-  const noUndef = JSON.parse(JSON.stringify(rest))
-  if (coreSignatures) {
-    noUndef.coreSignatures = coreSignatures
-  }
-  if (identitySignature) {
-    noUndef.identitySignature = identitySignature
-  }
-  return noUndef
+  return JSON.parse(JSON.stringify(obj), (key, value) => {
+    if (value.type === 'Buffer') {
+      return Buffer.from(value.data)
+    }
+    return value
+  })
 }