Class Application

application.ts:452–931

 */
// deno-lint-ignore no-explicit-any
export class Application<AS extends State = Record<string, any>>
  extends EventTarget {
  #composedMiddleware?: (context: Context<AS, AS>) => Promise<unknown>;
  #contextOptions: Pick<
    ApplicationOptions<AS, ServerRequest>,
    "jsonBodyReplacer" | "jsonBodyReviver"
  >;
  #contextState: "clone" | "prototype" | "alias" | "empty";
  #keys?: KeyStack;
  #middleware: MiddlewareOrMiddlewareObject<State, Context<State, AS>>[] = [];
  #serverConstructor: ServerConstructor<ServerRequest> | undefined;

  /** A set of keys, or an instance of `KeyStack` which will be used to sign
   * cookies read and set by the application to avoid tampering with the
   * cookies. */
  get keys(): KeyStack | Key[] | undefined {
    return this.#keys;
  }

  set keys(keys: KeyStack | Key[] | undefined) {
    if (!keys) {
      this.#keys = undefined;
      return;
    } else if (Array.isArray(keys)) {
      this.#keys = new KeyStack(keys);
    } else {
      this.#keys = keys;
    }
  }

  /** If `true`, proxy headers will be trusted when processing requests.  This
   * defaults to `false`. */
  proxy: boolean;

  /** Generic state of the application, which can be specified by passing the
   * generic argument when constructing:
   *
   *       const app = new Application<{ foo: string }>();
   *
   * Or can be contextually inferred based on setting an initial state object:
   *
   *       const app = new Application({ state: { foo: "bar" } });
   *
   * When a new context is created, the application's state is cloned and the
   * state is unique to that request/response.  Changes can be made to the
   * application state that will be shared with all contexts.
   */
  state: AS;

  constructor(options: ApplicationOptions<AS, ServerRequest> = {}) {
    super();
    const {
      state,
      keys,
      proxy,
      serverConstructor,
      contextState = "clone",
      logErrors = true,