chore: simplify serialization a bit

src/async/deserializeAsync.ts

@@ -76,6 +76,12 @@ export function createTsonParseAsync(opts: TsonAsyncOptions): TsonParseAsync {
 
 							deferreds.set(idx, deferred);
 
+							if (typeof window === "undefined") {
+								deferred.promise.catch(() => {
+									// prevent unhandled promise rejection crashes 🤷‍♂️
+								});
+							}
+
 							return deferred.promise;
 						},
 					);
@@ -94,27 +100,31 @@ export function createTsonParseAsync(opts: TsonAsyncOptions): TsonParseAsync {
 		) {
 			function readLine(str: string) {
 				str = str.trimStart();
-				if (!str) {
-					return;
-				}
 
 				if (str.startsWith(",")) {
 					// ignore leading comma
 					str = str.slice(1);
 				}
 
-				if (!str.startsWith("[")) {
+				if (str.length < 2) {
+					// minimum length is 2: '[]'
 					return;
 				}
 
 				// console.log("got something that looks like a value", str);
 
 				const [index, status, result] = JSON.parse(str) as TsonAsyncValueTuple;
 
-				// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-				const deferred = deferreds.get(index)!;
-
+				const deferred = deferreds.get(index);
+				// console.log("got value", index, status, result, deferred);
 				const walkedResult = walk(result);
+
+				if (!deferred) {
+					throw new TsonError(
+						`No deferred found for index ${index} (status: ${status})`,
+					);
+				}
+
 				status === PROMISE_RESOLVED
 					? deferred.resolve(walkedResult)
 					: deferred.reject(
@@ -156,7 +166,7 @@ export function createTsonParseAsync(opts: TsonAsyncOptions): TsonParseAsync {
 				lines.push(...(lastResult.value as string).split("\n").filter(Boolean));
 
 				// console.log("got line", lines);
-			} while (lines.length < 4);
+			} while (lines.length < 2);
 
 			const [
 				/**
@@ -166,31 +176,22 @@ export function createTsonParseAsync(opts: TsonAsyncOptions): TsonParseAsync {
 				/**
 				 * Second line is the shape of the JSON
 				 */
-				secondLine,
-				/**
-				 * Third line is a `,`
-				 */
-				_thirdLine,
-				/**
-				 * Fourth line is the start of the values array
-				 */
-				_fourthLine,
-				/**
-				 * Buffer is the rest of the iterator that came in the chunks while we were waiting for the first 4 lines
-				 */
+				headLine,
+				// .. third line is a `,`
+				// .. fourth line is the start of the values array
 				...buffer
 			] = lines;
 
 			// eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-			const secondValueParsed = JSON.parse(secondLine!) as TsonSerialized<any>;
+			const head = JSON.parse(headLine!) as TsonSerialized<any>;
 
-			const walk = walker(secondValueParsed.nonce);
+			const walk = walker(head.nonce);
 
 			void getStreamedValues(buffer, !!lastResult.done, walk).catch((cause) => {
 				// Something went wrong while getting the streamed values
 
 				const err = new TsonError(
-					"Stream interrupted: failed to get streamed values",
+					`Stream interrupted: ${(cause as Error).message}`,
 					// eslint-disable-next-line @typescript-eslint/no-unsafe-assignment
 					{ cause },
 				);
@@ -203,7 +204,7 @@ export function createTsonParseAsync(opts: TsonAsyncOptions): TsonParseAsync {
 				deferreds.clear();
 			});
 
-			return walk(secondValueParsed.json);
+			return walk(head.json);
 		}
 
 		const result = await init().catch((cause: unknown) => {

src/handlers/tsonPromise.test.ts

@@ -205,7 +205,6 @@ test("stringifier - no promises", async () => {
 		buffer.push(value.trimEnd());
 	}
 
-	// expect(buffer).toHaveLength(5);
 	expect(buffer).toMatchInlineSnapshot(`
 		[
 		  "[",
@@ -388,6 +387,7 @@ test("stringify and parse promise with a promise over a network connection", asy
 		}>;
 	}
 
+	// ----- server --------
 	const server = await new Promise<http.Server>((resolve) => {
 		const server = http.createServer((_req, res) => {
 			async function handle() {
@@ -404,7 +404,7 @@ test("stringify and parse promise with a promise over a network connection", asy
 							}, 8),
 							rejectedPromise: createPromise<number>(() => {
 								throw new Error("foo");
-							}, 10),
+							}, 1),
 						};
 					}, 3),
 				};
@@ -428,6 +428,12 @@ test("stringify and parse promise with a promise over a network connection", asy
 	// eslint-disable-next-line @typescript-eslint/no-unsafe-member-access, @typescript-eslint/no-explicit-any
 	const port = (server.address() as any).port as number;
 
+	// ----- client --------
+	const tson = createTsonAsync({
+		nonce: () => "__tson",
+		types: [tsonPromise],
+	});
+
 	// do a streamed fetch request
 	const response = await fetch(`http://localhost:${port}`);
 
@@ -440,18 +446,17 @@ test("stringify and parse promise with a promise over a network connection", asy
 		readableStreamToAsyncIterable(response.body),
 		(v) => textDecoder.decode(v),
 	);
-	const tson = createTsonAsync({
-		nonce: () => "__tson",
-		types: [tsonPromise],
-	});
-
 	const value = await tson.parse(stringIterator);
 	const asObj = value as Obj;
 
 	const firstPromise = await asObj.promise;
 
 	expect(firstPromise).toHaveProperty("anotherPromise");
 
+	const secondPromise = await firstPromise.anotherPromise;
+
+	expect(secondPromise).toBe(42);
+
 	// eslint-disable-next-line @typescript-eslint/no-unsafe-return
 	const err = await firstPromise.rejectedPromise.catch((err) => err);
 	assert.instanceOf(err, Error);
@@ -463,10 +468,6 @@ test("stringify and parse promise with a promise over a network connection", asy
 		}
 	`);
 
-	const secondPromise = await firstPromise.anotherPromise;
-
-	expect(secondPromise).toBe(42);
-
 	expect(err).toMatchInlineSnapshot("[TsonError: Promise rejected on server]");
 
 	server.close();