Add InitStatus class

srcts/src/shiny/index.ts

@@ -27,7 +27,11 @@ import {
   mapValues,
   pixelRatio,
 } from "../utils";
-import { promiseWithResolvers } from "../utils/promise";
+import {
+  createInitStatus,
+  promiseWithResolvers,
+  type InitStatus,
+} from "../utils/promise";
 import type { BindInputsCtx, BindScope } from "./bind";
 import { bindAll, unbindAll, _bindAll } from "./bind";
 import type {
@@ -97,13 +101,9 @@ class ShinyClass {
   unbindAll?: typeof shinyUnbindAll;
   initializeInputs?: typeof shinyInitializeInputs;
 
-  isConnected: PromiseLike<ShinyWebSocket>;
-  // eslint-disable-next-line @typescript-eslint/naming-convention
-  _resolveIsConnected: (value: ShinyWebSocket) => void;
-
-  isInitialized: PromiseLike<void>;
-  // eslint-disable-next-line @typescript-eslint/naming-convention
-  _resolveIsInitialized: (value: void) => void;
+  // Promise-like objects that are resolved at various stages of initialization.
+  isConnected: InitStatus<ShinyWebSocket>;
+  isInitialized: InitStatus<void>;
 
   // Eventually deprecate
   // For old-style custom messages - should deprecate and migrate to new
@@ -142,13 +142,8 @@ class ShinyClass {
     this.renderHtmlAsync = renderHtmlAsync;
     this.renderHtml = renderHtml;
 
-    const connectedPromise = promiseWithResolvers<ShinyWebSocket>();
-    this.isConnected = connectedPromise.promise;
-    this._resolveIsConnected = connectedPromise.resolve;
-
-    const initPromise = promiseWithResolvers<void>();
-    this.isInitialized = initPromise.promise;
-    this._resolveIsInitialized = initPromise.resolve;
+    this.isConnected = createInitStatus<ShinyWebSocket>();
+    this.isInitialized = createInitStatus<void>();
 
     $(() => {
       // Init Shiny a little later than document ready, so user code can
@@ -689,11 +684,11 @@ class ShinyClass {
       initDeferredIframes();
       // @ts-expect-error; .socket property isn't a known property of
       // JQuery.TriggeredEvent, but it was added on there anyway.
-      this._resolveIsConnected(event.socket);
+      this.isConnected.resolve(event.socket);
     });
 
     $(document).one("shiny:sessioninitialized", () => {
-      this._resolveIsInitialized();
+      this.isInitialized.resolve();
     });
   }
 }

srcts/src/utils/promise.ts

@@ -17,3 +17,30 @@ export function promiseWithResolvers<T>(): {
   // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
   return { promise, resolve: resolve!, reject: reject! };
 }
+
+export interface InitStatus<T> extends Promise<T> {
+  promise: Promise<T>;
+  resolve(x: T): void;
+  resolved(): boolean;
+}
+
+export function createInitStatus<T>(): InitStatus<T> {
+  const { promise, resolve } = promiseWithResolvers<T>();
+  // eslint-disable-next-line @typescript-eslint/naming-convention
+  let _resolved = false;
+
+  return {
+    promise,
+    resolve(x: T) {
+      _resolved = true;
+      resolve(x);
+    },
+    then: promise.then.bind(promise),
+    catch: promise.catch.bind(promise),
+    finally: promise.finally.bind(promise),
+    [Symbol.toStringTag]: "InitStatus",
+    resolved() {
+      return _resolved;
+    },
+  };
+}