fix: Resolve TypeScript errors

Signed-off-by: Hermes Agent <hermes@nosuchhost>

client/node_modules/abstract-leveldown/test/factory-test.js

@@ -0,0 +1,37 @@
+var concat = require('level-concat-iterator')
+
+module.exports = function (test, testCommon) {
+  test('setUp common', testCommon.setUp)
+
+  test('testCommon.factory() returns a unique database', function (t) {
+    var db1 = testCommon.factory()
+    var db2 = testCommon.factory()
+
+    function close () {
+      db1.close(function (err) {
+        t.error(err, 'no error while closing db1')
+        db2.close(function (err) {
+          t.error(err, 'no error while closing db2')
+          t.end()
+        })
+      })
+    }
+
+    db1.open(function (err) {
+      t.error(err, 'no error while opening db1')
+      db2.open(function (err) {
+        t.error(err, 'no error while opening db2')
+        db1.put('key', 'value', function (err) {
+          t.error(err, 'put key in db1')
+          concat(db2.iterator(), function (err, entries) {
+            t.error(err, 'got items from db2')
+            t.same(entries, [], 'db2 should be empty')
+            close()
+          })
+        })
+      })
+    })
+  })
+
+  test('tearDown', testCommon.tearDown)
+}