@cloudflare/kv-asset-handler/src/mocks.ts

Routes requests to KV assets

import makeServiceWorkerEnv from "service-worker-mock";

const HASH = "123HASHBROWN";

export const getEvent = (
	request: Request
): Pick<FetchEvent, "request" | "waitUntil"> => {
	const waitUntil = async (maybePromise: unknown) => {
		await maybePromise;
	};
	return {
		request,
		waitUntil,
	};
};
const store = {
	"key1.123HASHBROWN.txt": "val1",
	"key1.123HASHBROWN.png": "val1",
	"index.123HASHBROWN.html": "index.html",
	"cache.123HASHBROWN.html": "cache me if you can",
	"测试.123HASHBROWN.html": "My filename is non-ascii",
	"%not-really-percent-encoded.123HASHBROWN.html": "browser percent encoded",
	"%2F.123HASHBROWN.html": "user percent encoded",
	"你好.123HASHBROWN.html": "I shouldnt be served",
	"%E4%BD%A0%E5%A5%BD.123HASHBROWN.html": "Im important",
	"nohash.txt": "no hash but still got some result",
	"sub/blah.123HASHBROWN.png": "picturedis",
	"sub/index.123HASHBROWN.html": "picturedis",
	"client.123HASHBROWN": "important file",
	"client.123HASHBROWN/index.html": "Im here but serve my big bro above",
	"image.123HASHBROWN.png": "imagepng",
	"image.123HASHBROWN.webp": "imagewebp",
	"你好/index.123HASHBROWN.html": "My path is non-ascii",
};
export const mockKV = (kvStore: Record<string, string>) => {
	return {
		get: (path: string) => kvStore[path] || null,
	};
};

export const mockManifest = () => {
	return JSON.stringify({
		"key1.txt": `key1.${HASH}.txt`,
		"key1.png": `key1.${HASH}.png`,
		"cache.html": `cache.${HASH}.html`,
		"测试.html": `测试.${HASH}.html`,
		"你好.html": `你好.${HASH}.html`,
		"%not-really-percent-encoded.html": `%not-really-percent-encoded.${HASH}.html`,
		"%2F.html": `%2F.${HASH}.html`,
		"%E4%BD%A0%E5%A5%BD.html": `%E4%BD%A0%E5%A5%BD.${HASH}.html`,
		"index.html": `index.${HASH}.html`,
		"sub/blah.png": `sub/blah.${HASH}.png`,
		"sub/index.html": `sub/index.${HASH}.html`,
		client: `client.${HASH}`,
		"client/index.html": `client.${HASH}`,
		"image.png": `image.${HASH}.png`,
		"image.webp": `image.${HASH}.webp`,
		"你好/index.html": `你好/index.${HASH}.html`,
	});
};

const cacheStore = new Map<string, Response>();
interface CacheKey {
	url: string;
	headers: HeadersInit;
}
export const mockCaches = () => {
	return {
		default: {
			async match(key: Request) {
				const cacheKey: CacheKey = {
					url: key.url,
					headers: {},
				};
				let response;
				if (key.headers.has("if-none-match")) {
					const makeStrongEtag = key.headers
						.get("if-none-match")
						.replace("W/", "");
					Reflect.set(cacheKey.headers, "etag", makeStrongEtag);
					response = cacheStore.get(JSON.stringify(cacheKey));
				} else {
					// if client doesn't send if-none-match, we need to iterate through these keys
					// and just test the URL
					const activeCacheKeys: Array<string> = Array.from(cacheStore.keys());
					for (const cacheStoreKey of activeCacheKeys) {
						if (JSON.parse(cacheStoreKey).url === key.url) {
							response = cacheStore.get(cacheStoreKey);
						}
					}
				}
				// TODO: write test to accomodate for rare scenarios with where range requests accomodate etags
				if (response && !key.headers.has("if-none-match")) {
					// this appears overly verbose, but is necessary to document edge cache behavior
					// The Range request header triggers the response header Content-Range ...
					const range = key.headers.get("range");
					if (range) {
						response.headers.set(
							"content-range",
							`bytes ${range.split("=").pop()}/${response.headers.get(
								"content-length"
							)}`
						);
					}
					// ... which we are using in this repository to set status 206
					if (response.headers.has("content-range")) {
						// @ts-expect-error overridding status in this mock
						response.status = 206;
					} else {
						// @ts-expect-error overridding status in this mock
						response.status = 200;
					}
					const etag = response.headers.get("etag");
					if (etag && !etag.includes("W/")) {
						response.headers.set("etag", `W/${etag}`);
					}
				}
				return response;
			},
			async put(key: Request, val: Response) {
				const headers = new Headers(val.headers);
				const url = new URL(key.url);
				const resWithBody = new Response(val.body, { headers, status: 200 });
				const resNoBody = new Response(null, { headers, status: 304 });
				const cacheKey: CacheKey = {
					url: key.url,
					headers: {
						etag: `"${url.pathname.replace("/", "")}"`,
					},
				};
				cacheStore.set(JSON.stringify(cacheKey), resNoBody);
				cacheKey.headers = {};
				cacheStore.set(JSON.stringify(cacheKey), resWithBody);
				return;
			},
		},
	};
};

// mocks functionality used inside worker request
export function mockRequestScope() {
	Object.assign(globalThis, makeServiceWorkerEnv());
	Object.assign(globalThis, { __STATIC_CONTENT_MANIFEST: mockManifest() });
	Object.assign(globalThis, { __STATIC_CONTENT: mockKV(store) });
	Object.assign(globalThis, { caches: mockCaches() });
}

// mocks functionality used on global isolate scope. such as the KV namespace bind
export function mockGlobalScope() {
	Object.assign(globalThis, { __STATIC_CONTENT_MANIFEST: mockManifest() });
	Object.assign(globalThis, { __STATIC_CONTENT: mockKV(store) });
}

export const sleep = (milliseconds: number) => {
	return new Promise((resolve) => setTimeout(resolve, milliseconds));
};