fix: Resolve TypeScript errors

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

client/node_modules/level/test-browser.js

@@ -0,0 +1,81 @@
+'use strict'
+
+// Promise polyfill for IE and others.
+if (typeof Promise !== 'function') {
+  global.Promise = require('pinkie')
+}
+
+var test = require('tape')
+var uuid = require('uuid/v4')
+var level = require('.')
+
+require('level-packager/abstract/base-test')(test, level)
+require('level-packager/abstract/db-values-test')(test, level)
+
+function factory (opts) {
+  return level(uuid(), opts)
+}
+
+test('level put', function (t) {
+  t.plan(4)
+
+  var db = factory()
+
+  db.put('name', 'level', function (err) {
+    t.ifError(err, 'no put error')
+
+    db.get('name', function (err, value) {
+      t.ifError(err, 'no get error')
+      t.is(value, 'level')
+
+      db.close(function (err) {
+        t.ifError(err, 'no close error')
+      })
+    })
+  })
+})
+
+test('level Buffer value', function (t) {
+  t.plan(5)
+
+  var db = factory({ valueEncoding: 'binary' })
+  var buf = Buffer.from('00ff', 'hex')
+
+  db.put('binary', buf, function (err) {
+    t.ifError(err, 'no put error')
+
+    db.get('binary', function (err, value) {
+      t.ifError(err, 'no get error')
+      t.ok(Buffer.isBuffer(value), 'is a buffer')
+      t.same(value, buf)
+
+      db.close(function (err) {
+        t.ifError(err, 'no close error')
+      })
+    })
+  })
+})
+
+test('level Buffer key', function (t) {
+  var db = factory({ keyEncoding: 'binary' })
+  var key = Buffer.from('00ff', 'hex')
+
+  if (!db.supports.bufferKeys) {
+    t.pass('Environment does not support buffer keys')
+    return t.end()
+  }
+
+  db.put(key, 'value', function (err) {
+    t.ifError(err, 'no put error')
+
+    db.get(key, function (err, value) {
+      t.ifError(err, 'no get error')
+      t.is(value, 'value')
+
+      db.close(function (err) {
+        t.ifError(err, 'no close error')
+        t.end()
+      })
+    })
+  })
+})