add simple test to make sure that a range compaction does infact redu…

…ce the size of the database

test/compact-range-test.js

@@ -0,0 +1,37 @@
+const test       = require('tape')
+    , testCommon = require('abstract-leveldown/testCommon')
+    , leveldown  = require('../')
+
+var db
+
+test('setUp common', testCommon.setUp)
+
+test('setUp db', function (t) {
+  db = leveldown(testCommon.location())
+  db.open(t.end.bind(t))
+})
+
+test('test compactRange() frees disk space after key deletion', function (t) {
+  var key1 = '000000';
+  var key2 = '000001';
+  var val1 = Buffer(64).fill(1);
+  var val2 = Buffer(64).fill(1);
+  db.put(key1, val1, function() {
+    db.put(key2, val2, function() {
+      db.compactRange(key1, key2, function() {
+        db.approximateSize('0', 'z', function(err, sizeAfterPuts) {
+          db.del(key1, function() {
+            db.del(key2, function() {
+              db.compactRange(key1, key2, function() {
+                db.approximateSize('0', 'z', function(err, sizeAfterCompact) {
+                  t.notEqual(sizeAfterCompact, sizeAfterPuts);
+                  t.end();
+                });
+              });
+            });
+          });
+        });
+      });
+    });
+  });
+});