From 91324b2531f95f5dd1c147b2003c0a7bc85884bc Mon Sep 17 00:00:00 2001
From: Christopher Jeffrey <chjjeffrey@gmail.com>
Date: Sat, 10 Sep 2016 23:56:18 -0700
Subject: [PATCH] ldb: error on missing features.

---
 lib/db/lowlevelup.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/db/lowlevelup.js b/lib/db/lowlevelup.js
index 63ee4373..5e94fc9c 100644
--- a/lib/db/lowlevelup.js
+++ b/lib/db/lowlevelup.js
@@ -85,7 +85,7 @@ LowlevelUp.prototype.destroy = function destroy(callback) {
   assert(!this.loaded);
 
   if (!this.backend.destroy)
-    return utils.nextTick(callback);
+    return utils.asyncify(callback)(new Error('Cannot destroy.'));
 
   this.backend.destroy(this.location, callback);
 };
@@ -225,6 +225,10 @@ LowlevelUp.prototype.getProperty = function getProperty(name) {
 
 LowlevelUp.prototype.approximateSize = function approximateSize(start, end, callback) {
   assert(this.loaded, 'Cannot use database before it is loaded.');
+
+  if (!this.binding.approximateSize)
+    return utils.asyncify(callback)(new Error('Cannot get size.'));
+
   this.binding.approximateSize(start, end, callback);
 };