fix: Resolve TypeScript errors

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

client/node_modules/abstract-leveldown/test/open-create-if-missing-test.js

@@ -0,0 +1,29 @@
+exports.setUp = function (test, testCommon) {
+  test('setUp', testCommon.setUp)
+}
+
+exports.createIfMissing = function (test, testCommon) {
+  test('test database open createIfMissing:false', function (t) {
+    var db = testCommon.factory()
+    var async = false
+
+    db.open({ createIfMissing: false }, function (err) {
+      t.ok(err, 'error')
+      t.ok(/does not exist/.test(err.message), 'error is about dir not existing')
+      t.ok(async, 'callback is asynchronous')
+      t.end()
+    })
+
+    async = true
+  })
+}
+
+exports.tearDown = function (test, testCommon) {
+  test('tearDown', testCommon.tearDown)
+}
+
+exports.all = function (test, testCommon) {
+  exports.setUp(test, testCommon)
+  exports.createIfMissing(test, testCommon)
+  exports.tearDown(test, testCommon)
+}