Add TypeScript type definitions

These are useful for library developers and keeping them here ensures they'll stay in sync with the spec/explainer.

Eventually this might be published as an npm package and/or move to DefinitelyTyped.

Author: tbondwilkinson

app_history.d.ts

@@ -0,0 +1,98 @@
+interface Window {
+  readonly appHistory: AppHistory;
+}
+
+declare class AppHistory extends EventTarget {
+  readonly current: AppHistoryEntry|null;
+  readonly transition: AppHistoryTransition|null;
+
+  entries(): AppHistoryEntry[];
+
+  readonly canGoBack: boolean;
+  readonly canGoForward: boolean;
+
+  navigate(url: string, options?: AppHistoryNavigateOptions): Promise<void>;
+  reload(options?: AppHistoryReloadOptions): Promise<void>;
+
+  goTo(key: string, options?: AppHistoryNavigationOptions): Promise<void>;
+  back(options?: AppHistoryNavigationOptions): Promise<void>;
+  forward(options?: AppHistoryNavigationOptions): Promise<void>;
+
+  onnavigate: ((this: AppHistory, ev: AppHistoryNavigateEvent) => any)|null;
+  onnavigatesuccess: ((this: AppHistory, ev: Event) => any)|null;
+  onnavigateerror: ((this: AppHistory, ev: ErrorEvent) => any)|null;
+}
+
+declare class AppHistoryTransition {
+  readonly navigationType: AppHistoryNavigationType;
+  readonly from: AppHistoryEntry;
+  readonly finished: Promise<void>;
+
+  rollback(options?: AppHistoryNavigationOptions): Promise<void>;
+}
+
+declare class AppHistoryEntry extends EventTarget {
+  readonly key: string;
+  readonly id: string;
+  readonly url: string;
+  readonly index: number;
+  readonly sameDocument: boolean;
+
+  getState(): unknown;
+
+  onnavigateto: ((this: AppHistoryEntry, ev: Event) => any)|null;
+  onnavigatefrom: ((this: AppHistoryEntry, ev: Event) => any)|null;
+  onfinish: ((this: AppHistoryEntry, ev: Event) => any)|null;
+  ondispose: ((this: AppHistoryEntry, ev: Event) => any)|null;
+}
+
+type AppHistoryNavigationType = 'reload'|'push'|'replace'|'traverse';
+
+interface AppHistoryNavigationOptions {
+  navigateInfo?: unknown;
+}
+
+interface AppHistoryNavigateOptions extends AppHistoryNavigationOptions {
+  state?: unknown;
+  replace?: boolean;
+}
+
+interface AppHistoryReloadOptions extends AppHistoryNavigationOptions {
+  state?: unknown;
+}
+
+declare class AppHistoryNavigateEvent extends Event {
+  constructor(type: string, eventInit: AppHistoryNavigateEventInit);
+
+  readonly navigationType: AppHistoryNavigationType;
+  readonly canRespond: boolean;
+  readonly userInitiated: boolean;
+  readonly hashChange: boolean;
+  readonly destination: AppHistoryDestination;
+  readonly signal: AbortSignal;
+  readonly formData: FormData|null;
+  readonly info: unknown;
+
+  respondWith(newNavigationAction: Promise<void>): void;
+}
+
+interface AppHistoryNavigateEventInit extends EventInit {
+  navigationType?: AppHistoryNavigationType;
+  canRespond?: boolean;
+  userInitiated?: boolean;
+  hashChange?: boolean;
+  destination: AppHistoryDestination;
+  signal: AbortSignal;
+  formData?: FormData|null;
+  info?: unknown;
+}
+
+declare class AppHistoryDestination {
+  readonly url: string;
+  readonly key: string|null;
+  readonly id: string|null;
+  readonly index: number;
+  readonly sameDocument: boolean;
+
+  getState(): unknown;
+}