captoys/diigo-cache/tests/webkeys.test.ts

import { describe, expect, it } from "vitest";
import {
	yurl32,
	unyurl32,
	hexToBytes,
	bytesToHex,
	glyphsFor,
	bytesInGlyphs,
	toWebkey,
	idFromWebkey,
	isWebkey,
	shashKey,
	type DurableObjectIdLike,
} from "../src/webkeys.js";

// @ts-expect-error vite raw import
import webkeysSource from "../src/webkeys.ts?raw";

const sampleHex = "ab9d14667a05453602b28218c3dc60995d890e49c1502ee1fffa2d0815b367ee";

/** mock a Cloudflare DurableObjectId */
function mockDurableObjectId(hex = sampleHex): DurableObjectIdLike {
	return {
		toString: () => hex,
		equals: (other: unknown) =>
			typeof other === "object" &&
			other !== null &&
			"toString" in other &&
			(other as { toString(): string }).toString() === hex,
	};
}

describe("yurl32 and hex codecs", () => {
	it("matches the paper's alphabet sample", () => {
		expect("mhbqcmmva5ja3").toMatch(/^[a-z2-7]{13}$/);
	});

	it("encodes 5 bits per glyph", () => {
		expect(glyphsFor(64)).toBe(13);
		expect(glyphsFor(128)).toBe(26);
		expect(glyphsFor(160)).toBe(32);
		expect(glyphsFor(256)).toBe(52);
		expect(bytesInGlyphs(26)).toBe(16);
		expect(bytesInGlyphs(52)).toBe(32);
	});

	it("round-trips hex bytes", () => {
		const bytes = hexToBytes(sampleHex);
		expect(bytes.length).toBe(32);
		expect(bytesToHex(bytes)).toBe(sampleHex);
	});

	it("round-trips bytes through yurl32", () => {
		const bytes = hexToBytes(sampleHex);
		const encoded = yurl32(bytes);
		expect(encoded).toMatch(/^[a-z2-7]+$/);
		expect(encoded.length).toBe(52);
		expect(unyurl32(encoded)).toEqual(bytes);
	});

	it("handles leftovers: 0xff encodes to '74'", () => {
		expect(yurl32(new Uint8Array([0xff]))).toBe("74");
	});

	it("refuses garbage", () => {
		expect(() => unyurl32("0OIl")).toThrow(/not YURL32/);
		expect(() => unyurl32("AAAA-")).toThrow();
		expect(() => hexToBytes("abc")).toThrow(/invalid hex length/);
		expect(() => hexToBytes("zz")).toThrow(/invalid hex byte/);
	});
});

describe("toWebkey and idFromWebkey (aligning with Worker unique ID)", () => {
	it("converts a DurableObjectId to a 52-glyph YURL32 webkey", () => {
		const doId = mockDurableObjectId();
		const webkey = toWebkey(doId);
		expect(webkey.length).toBe(52);
		expect(webkey).toMatch(/^[a-z2-7]{52}$/);
		expect(isWebkey(webkey)).toBe(true);
	});

	it("round-trips DurableObjectId -> webkey -> hex string", () => {
		const doId = mockDurableObjectId();
		const webkey = toWebkey(doId);
		const hex = idFromWebkey(webkey);
		expect(hex).toBe(sampleHex);
	});

	it("accepts a raw 64-char hex string as input to toWebkey", () => {
		const webkey = toWebkey(sampleHex);
		expect(webkey.length).toBe(52);
		expect(idFromWebkey(webkey)).toBe(sampleHex);
	});

	it("accepts an already-hex ID in idFromWebkey for backward compatibility", () => {
		expect(idFromWebkey(sampleHex)).toBe(sampleHex);
		expect(idFromWebkey(sampleHex.toUpperCase())).toBe(sampleHex);
	});

	it("encodes raw 16-byte (128-bit) entropy directly", () => {
		const bytes = new Uint8Array(16).fill(42);
		const webkey = toWebkey(bytes);
		expect(webkey.length).toBe(26);
		expect(isWebkey(webkey)).toBe(true);
		expect(isWebkey(webkey, 128)).toBe(true);
		expect(unyurl32(webkey)).toEqual(bytes);
	});

	it("refuses malformed or wrong-sized webkeys in idFromWebkey", () => {
		expect(() => idFromWebkey("short")).toThrow();
		// 26-char (128-bit) webkey is valid YURL32, but not a 256-bit Worker ID:
		const short128 = toWebkey(new Uint8Array(16));
		expect(() => idFromWebkey(short128)).toThrow(/expected 32 bytes/);
	});
});

describe("shashKey (swissHash discipline)", () => {
	it("is one-way: identity, not authority", async () => {
		const doId = mockDurableObjectId();
		const h = await shashKey(doId);
		expect(h).toMatch(/^[a-z2-7]+$/);
		expect(h.length).toBe(52);
		expect(h).not.toBe(toWebkey(doId));
	});

	it("is deterministic (joinable in logs)", async () => {
		const doId = mockDurableObjectId();
		expect(await shashKey(doId)).toBe(await shashKey(doId));
	});
});

describe("no ambient authority in this module", () => {
	it("the module's functions take their effects as arguments", () => {
		// strip comments before inspecting executable code
		const code = webkeysSource.replace(/\/\*[\s\S]*?\*\/|\/\/.*/g, "");
		expect(code.includes("getRandomValues")).toBe(false);
		expect(code.match(/crypto\.subtle/g)?.length ?? 0).toBe(1); // shashKey only
	});
});