feat: use a UUID for nonce

README.md

@@ -60,9 +60,12 @@ import {
 } from "tupleson";
 
 const tson = createTson({
-	// This nonce function is used to generate a nonce for the serialized value
-	// This is used to identify the value as a serialized value
-	nonce: () => "__tson",
+	/**
+	 * The nonce function every time we start serializing a new object
+	 * Should return a unique value every time it's called
+	 * @default `${crypto.randomUUID} if available, otherwise a random string generated by Math.random`
+	 */
+	// nonce: () => "__tson",
 	types: [
 		// Pick which types you want to support
 		tsonSet,

src/extend/decimal.test.ts

@@ -11,6 +11,7 @@ const decimalJs: TsonType<Decimal, string> = {
 };
 
 const tson = createTson({
+	nonce: () => "__tson",
 	types: [decimalJs],
 });
 

src/handlers/tsonRegExp.test.ts

@@ -5,6 +5,7 @@ import { tsonRegExp } from "./index.js";
 
 test("regex", () => {
 	const t = createTson({
+		nonce: () => "__tson",
 		types: [tsonRegExp],
 	});
 

src/handlers/tsonURL.test.ts

@@ -5,6 +5,7 @@ import { tsonURL } from "./index.js";
 
 test("URL", () => {
 	const ctx = createTson({
+		nonce: () => "__tson",
 		types: [tsonURL],
 	});
 

src/internals/getNonce.crypto.test.ts

@@ -0,0 +1,16 @@
+// eslint-disable-next-line eslint-comments/disable-enable-pair
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { expect, test } from "vitest";
+
+test("with crypto", async () => {
+	const before = global.crypto;
+
+	global.crypto = {
+		randomUUID: () => "test",
+	} as any;
+	const { getNonce } = await import("./getNonce.js");
+
+	expect(getNonce()).toBe("test");
+
+	global.crypto = before;
+});

src/internals/getNonce.nocrypto.test.ts

@@ -0,0 +1,15 @@
+// eslint-disable-next-line eslint-comments/disable-enable-pair
+/* eslint-disable @typescript-eslint/no-explicit-any */
+import { expect, test } from "vitest";
+
+test("without crypto", async () => {
+	const before = global.crypto;
+
+	global.crypto = undefined as any;
+
+	const { getNonce } = await import("./getNonce.js");
+
+	expect(getNonce().length).toBeGreaterThan(20);
+
+	global.crypto = before;
+});

src/internals/getNonce.ts

@@ -0,0 +1,11 @@
+import { TsonNonce } from "../types.js";
+
+const randomString = () => Math.random().toString(36).slice(2);
+
+export type GetNonce = () => TsonNonce;
+
+export const getNonce: GetNonce =
+	typeof crypto === "object" && typeof crypto.randomUUID === "function"
+		? () => crypto.randomUUID() as TsonNonce
+		: () =>
+				[randomString(), randomString(), randomString()].join("") as TsonNonce;

src/serialize.ts

@@ -1,5 +1,6 @@
 /* eslint-disable @typescript-eslint/no-explicit-any, eslint-comments/disable-enable-pair */
 import { CircularReferenceError } from "./errors.js";
+import { GetNonce, getNonce } from "./internals/getNonce.js";
 import { mapOrReturn } from "./internals/mapOrReturn.js";
 import {
 	TsonAllTypes,
@@ -69,7 +70,6 @@ export function createTsonSerialize(opts: TsonOptions): TsonSerializeFn {
 
 		return [nonPrimitive, byPrimitive] as const;
 	})();
-	const maybeNonce = opts.nonce;
 
 	const [nonPrimitive, byPrimitive] = handlers;
 
@@ -122,11 +122,10 @@ export function createTsonSerialize(opts: TsonOptions): TsonSerializeFn {
 		return walk;
 	};
 
+	const nonceFn: GetNonce = opts.nonce ? (opts.nonce as GetNonce) : getNonce;
+
 	return ((obj): TsonSerialized => {
-		const nonce: TsonNonce =
-			typeof maybeNonce === "function"
-				? (maybeNonce() as TsonNonce)
-				: ("__tson" as TsonNonce);
+		const nonce = nonceFn();
 
 		const json = walker(nonce)(obj);
 

src/stringify.test.ts

@@ -8,6 +8,7 @@ import { tsonUndefined } from "./handlers/tsonUndefined.js";
 
 test("lets have a look at the stringified output", () => {
 	const t = createTson({
+		nonce: () => "__tson",
 		types: [tsonMap, tsonSet, tsonBigint, tsonUndefined],
 	});
 

src/types.ts

@@ -95,7 +95,15 @@ export type TsonType<
 > = TsonTypeTester & TsonTransformer<TValue, TSerializedType>;
 
 export interface TsonOptions {
+	/**
+	 * The nonce function every time we start serializing a new object
+	 * Should return a unique value every time it's called
+	 * @default `${crypto.randomUUID} if available, otherwise a random string generated by Math.random`
+	 */
 	nonce?: () => number | string;
+	/**
+	 * The list of types to use
+	 */
 	types: (TsonType<any, any> | TsonType<any, never>)[];
 }