George Kalpakas fb735d625b refactor(service-worker): use nominal type for normalized URLs (#37922)
Some ServiceWorker operations and methods require normalized URLs.
Previously, the generic `string` type was used.

This commit introduces a new `NormalizedUrl` type, a special kind of
`string`, to make this requirement explicit and use the type system to
enforce it.

PR Close #37922
2020-07-09 09:44:57 -07:00

117 lines
3.3 KiB
TypeScript

/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {NormalizedUrl} from './api';
/**
* Adapts the service worker to its runtime environment.
*
* Mostly, this is used to mock out identifiers which are otherwise read
* from the global scope.
*/
export class Adapter {
readonly cacheNamePrefix: string;
private readonly origin: string;
constructor(protected readonly scopeUrl: string) {
const parsedScopeUrl = this.parseUrl(this.scopeUrl);
// Determine the origin from the registration scope. This is used to differentiate between
// relative and absolute URLs.
this.origin = parsedScopeUrl.origin;
// Suffixing `ngsw` with the baseHref to avoid clash of cache names for SWs with different
// scopes on the same domain.
this.cacheNamePrefix = 'ngsw:' + parsedScopeUrl.path;
}
/**
* Wrapper around the `Request` constructor.
*/
newRequest(input: string|Request, init?: RequestInit): Request {
return new Request(input, init);
}
/**
* Wrapper around the `Response` constructor.
*/
newResponse(body: any, init?: ResponseInit) {
return new Response(body, init);
}
/**
* Wrapper around the `Headers` constructor.
*/
newHeaders(headers: {[name: string]: string}): Headers {
return new Headers(headers);
}
/**
* Test if a given object is an instance of `Client`.
*/
isClient(source: any): source is Client {
return (source instanceof Client);
}
/**
* Read the current UNIX time in milliseconds.
*/
get time(): number {
return Date.now();
}
/**
* Get a normalized representation of a URL such as those found in the ServiceWorker's `ngsw.json`
* configuration.
*
* More specifically:
* 1. Resolve the URL relative to the ServiceWorker's scope.
* 2. If the URL is relative to the ServiceWorker's own origin, then only return the path part.
* Otherwise, return the full URL.
*
* @param url The raw request URL.
* @return A normalized representation of the URL.
*/
normalizeUrl(url: string): NormalizedUrl {
// Check the URL's origin against the ServiceWorker's.
const parsed = this.parseUrl(url, this.scopeUrl);
return (parsed.origin === this.origin ? parsed.path : url) as NormalizedUrl;
}
/**
* Parse a URL into its different parts, such as `origin`, `path` and `search`.
*/
parseUrl(url: string, relativeTo?: string): {origin: string, path: string, search: string} {
// Workaround a Safari bug, see
// https://github.com/angular/angular/issues/31061#issuecomment-503637978
const parsed = !relativeTo ? new URL(url) : new URL(url, relativeTo);
return {origin: parsed.origin, path: parsed.pathname, search: parsed.search};
}
/**
* Wait for a given amount of time before completing a Promise.
*/
timeout(ms: number): Promise<void> {
return new Promise<void>(resolve => {
setTimeout(() => resolve(), ms);
});
}
}
/**
* An event context in which an operation is taking place, which allows
* the delaying of Service Worker shutdown until certain triggers occur.
*/
export interface Context {
/**
* Delay shutdown of the Service Worker until the given promise resolves.
*/
waitUntil(fn: Promise<any>): void;
}