message: tsc: preserveConstEnums
  So that DecodeHintType are available from JS.
diff: "alwaysStrict": true,
  "noImplicitAny": false,
  "sourceMap": true,
  - "declaration": true
  + "declaration": true,
  + "preserveConstEnums": true
  },
  "include": [
  "src/**/*.ts"
  