fix: Resolve TypeScript errors

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

client/node_modules/level-codec/test/as-buffer.js

@@ -0,0 +1,18 @@
+var test = require('tape')
+var Codec = require('..')
+
+test('key as buffer', function (t) {
+  var codec = new Codec({ keyEncoding: 'hex' })
+  t.ok(codec.keyAsBuffer({}))
+  t.ok(codec.keyAsBuffer())
+  t.notOk(codec.keyAsBuffer({ keyEncoding: 'utf8' }))
+  t.end()
+})
+
+test('value as buffer', function (t) {
+  var codec = new Codec({ valueEncoding: 'hex' })
+  t.ok(codec.valueAsBuffer({}))
+  t.ok(codec.valueAsBuffer())
+  t.notOk(codec.valueAsBuffer({ valueEncoding: 'utf8' }))
+  t.end()
+})