feat: deserializeAsync parse takes a ReadableStream Uint8Array as input

src/async/asyncTypes.ts

@@ -3,6 +3,10 @@ import { TsonType } from "../types.js";
 import { TsonBranded, TsonTypeTesterCustom } from "../types.js";
 import { serialized } from "../types.js";
 
+export type TsonAsyncStringifiedStream<TValue> = ReadableStream<Uint8Array> & {
+	[serialized]: TValue;
+};
+
 export type TsonAsyncStringifierIterable<TValue> = AsyncIterable<string> & {
 	[serialized]: TValue;
 };

src/async/deserializeAsync.test.ts

@@ -7,47 +7,44 @@
 	tsonPromise,
 } from "../index.js";
 import { assert } from "../internals/assert.js";
-import {
-	mapIterable,
-	readableStreamToAsyncIterable,
-} from "../internals/iterableUtils.js";
-import { createTestServer } from "../internals/testUtils.js";
+import { createTestServer, createBodyStream } from "../internals/testUtils.js";
 import { TsonAsyncOptions } from "./asyncTypes.js";
 
+
 test("deserialize variable chunk length", async () => {
 	const tson = createTsonAsync({
 		nonce: () => "__tson",
 		types: [tsonAsyncIterator, tsonPromise, tsonBigint],
 	});
 	{
-		const iterable = (async function* () {
+		const body = createBodyStream((async function* () {
 			await new Promise((resolve) => setTimeout(resolve, 1));
 			yield '[\n{"json":{"foo":"bar"},"nonce":"__tson"}';
 			yield "\n,\n[\n]\n]";
-		})();
-		const result = await tson.parse(iterable);
+		})());
+		const result = await tson.parse(body);
 		expect(result).toEqual({ foo: "bar" });
 	}
 
 	{
-		const iterable = (async function* () {
+		const body = createBodyStream((async function* () {
 			await new Promise((resolve) => setTimeout(resolve, 1));
 			yield '[\n{"json":{"foo":"bar"},"nonce":"__tson"}\n,\n[\n]\n]';
-		})();
-		const result = await tson.parse(iterable);
+		})());
+		const result = await tson.parse(body);
 		expect(result).toEqual({ foo: "bar" });
 	}
 
 	{
-		const iterable = (async function* () {
+		const body = createBodyStream((async function* () {
 			await new Promise((resolve) => setTimeout(resolve, 1));
 			yield '[\n{"json"';
 			yield ':{"foo":"b';
 			yield 'ar"},"nonce":"__tson"}\n,\n';
 			yield "[\n]\n";
 			yield "]";
-		})();
-		const result = await tson.parse(iterable);
+		})());
+		const result = await tson.parse(body);
 		expect(result).toEqual({ foo: "bar" });
 	}
 });
@@ -65,8 +62,8 @@
 		};
 
 		const strIterable = tson.stringify(obj);
-
-		const result = await tson.parse(strIterable);
+		const body = createBodyStream(strIterable);
+		const result = await tson.parse(body);
 
 		expect(result).toEqual(obj);
 	}
@@ -78,8 +75,9 @@
 		};
 
 		const strIterable = tson.stringify(obj);
-
-		const result = await tson.parse(strIterable);
+		const body = createBodyStream(strIterable);
+		const resultRaw = await tson.parse(body);
+		const result = resultRaw as typeof obj;
 
 		expect(await result.foo).toEqual("bar");
 	}
@@ -112,8 +110,9 @@
 	};
 
 	const strIterable = tson.stringify(input);
-
-	const output = await tson.parse(strIterable);
+	const body = createBodyStream(strIterable);
+	const outputRaw = await tson.parse(body);
+	const output = outputRaw as typeof input;
 
 	expect(output.foo).toEqual("bar");
 
@@ -175,15 +174,86 @@
 
 	assert(response.body);
 
-	const textDecoder = new TextDecoder();
+	const parsedRaw = await tson.parse(response.body);
+	const parsed = parsedRaw as MockObj;
+
+	expect(parsed.foo).toEqual("bar");
+
+	const results = [];
+
+	for await (const value of parsed.iterable) {
+		results.push(value);
+	}
+
+	expect(results).toEqual([1n, 2n, 3n, 4n, 5n]);
+
+	expect(await parsed.promise).toEqual(42);
+
+	await expect(
+		parsed.rejectedPromise,
+	).rejects.toThrowErrorMatchingInlineSnapshot('"Promise rejected"');
+
+	server.close();
+});
+
+test("e2e: server crash", async () => {
+	function createMockObj() {
+		async function* generator() {
+			for (const number of [1n, 2n, 3n, 4n, 5n]) {
+				await new Promise((resolve) => setTimeout(resolve, 1));
+				yield number;
+			}
+		}
 
-	// convert the response body to an async iterable
-	const stringIterator = mapIterable(
-		readableStreamToAsyncIterable(response.body),
-		(v) => textDecoder.decode(v),
-	);
+		return {
+			foo: "bar",
+			iterable: generator(),
+			promise: Promise.resolve(42),
+			rejectedPromise: Promise.reject(new Error("rejected promise")),
+		};
+	}
+
+	type MockObj = ReturnType<typeof createMockObj>;
+
+	// ------------- server -------------------
+	const opts: TsonAsyncOptions = {
+		types: [tsonPromise, tsonAsyncIterator, tsonBigint],
+	};
+
+	const server = await createTestServer({
+		handleRequest: async (_req, res) => {
+			const tson = createTsonAsync(opts);
+
+			const obj = createMockObj();
+			const strIterarable = tson.stringify(obj, 4);
+
+			let closed = false
+			setTimeout(() => {
+				closed = true
+				server.close();
+			}, 2)
+
+			// res.write(strIterarable);
+
+			for await (const value of strIterarable) {
+				if (closed) continue
+				res.write(value);
+			}
+
+			res.end();
+		},
+	});
+
+	// ------------- client -------------------
+	const tson = createTsonAsync(opts);
+
+	// do a streamed fetch request
+	const response = await fetch(server.url);
+
+	assert(response.body);
 
-	const parsed = await tson.parse<MockObj>(stringIterator);
+	const parsedRaw = await tson.parse(response.body);
+	const parsed = parsedRaw as MockObj;
 
 	expect(parsed.foo).toEqual("bar");
 

src/async/deserializeAsync.ts

@@ -12,7 +12,7 @@
 import {
 	TsonAsyncIndex,
 	TsonAsyncOptions,
-	TsonAsyncStringifierIterable,
+	TsonAsyncStringifiedStream,
 	TsonAsyncType,
 } from "./asyncTypes.js";
 import { TsonAsyncValueTuple } from "./serializeAsync.js";
@@ -25,7 +25,7 @@
 	| TsonTransformerSerializeDeserialize<any, any>;
 
 type TsonParseAsync = <TValue>(
-	string: AsyncIterable<string> | TsonAsyncStringifierIterable<TValue>,
+	string: ReadableStream<Uint8Array> | TsonAsyncStringifiedStream<TValue>,
 ) => Promise<TValue>;
 
 export function createTsonParseAsyncInner(opts: TsonAsyncOptions) {
@@ -42,13 +42,22 @@
 		}
 	}
 
-	return async (iterable: AsyncIterable<string>) => {
+	return async (stream: ReadableStream<Uint8Array>) => {
 		// this is an awful hack to get around making a some sort of pipeline
 		const cache = new Map<
 			TsonAsyncIndex,
 			ReadableStreamDefaultController<unknown>
 		>();
-		const iterator = iterable[Symbol.asyncIterator]();
+
+		const decoder = new TextDecoder();
+		const textStream = stream.pipeThrough(
+			new TransformStream<Uint8Array, string>({
+				async transform(chunk, controller) {
+					controller.enqueue(decoder.decode(chunk));
+				},
+			}),
+		);
+		const reader = textStream.getReader();
 
 		const walker: WalkerFactory = (nonce) => {
 			const walk: WalkFn = (value) => {
@@ -123,7 +132,7 @@
 			do {
 				lines.forEach(readLine);
 				lines.length = 0;
-				const nextValue = await iterator.next();
+				const nextValue = await reader.read();
 				if (!nextValue.done) {
 					accumulator += nextValue.value;
 					const parts = accumulator.split("\n");
@@ -144,7 +153,7 @@
 
 			const lines: string[] = [];
 			do {
-				const nextValue = await iterator.next();
+				const nextValue = await reader.read();
 				if (nextValue.done) {
 					throw new TsonError("Unexpected end of stream before head");
 				}

src/handlers/tsonPromise.test.ts

@@ -19,6 +19,7 @@
 	createTestServer,
 	waitError,
 	waitFor,
+	createBodyStream,
 } from "../internals/testUtils.js";
 import { TsonSerialized, TsonType } from "../types.js";
 
@@ -354,7 +355,8 @@
 
 	const strIterarable = tson.stringify(obj, 4);
 
-	const value = await tson.parse(strIterarable);
+	const valueRaw = await tson.parse(createBodyStream(strIterarable));
+	const value = valueRaw as typeof obj;
 
 	expect(value).toHaveProperty("foo");
 	expect(await value.foo).toBe("bar");
@@ -377,7 +379,8 @@
 
 	const strIterarable = tson.stringify(obj, 4);
 
-	const value = await tson.parse(strIterarable);
+	const valueRaw = await tson.parse(createBodyStream(strIterarable));
+	const value = valueRaw as typeof obj;
 
 	const firstPromise = await value.promise;
 
@@ -442,7 +445,7 @@
 		(v) => textDecoder.decode(v),
 	);
 
-	const value = await tson.parse(stringIterator);
+	const value = await tson.parse(createBodyStream(stringIterator));
 	const asObj = value as Obj;
 
 	const firstPromise = await asObj.promise;
@@ -481,7 +484,7 @@
 	};
 	const iterator = stringify(original);
 
-	const [_result, deferreds] = await parse(iterator);
+	const [_result, deferreds] = await parse(createBodyStream(iterator));
 
 	const result = _result as typeof original;
 	await waitFor(() => {
@@ -549,7 +552,8 @@
 		// parse
 		const iterator = stringify(original, 2);
 
-		const result = await parse(iterator);
+		const resultRaw = await parse(createBodyStream(iterator));
+		const result = resultRaw as typeof original;
 
 		expect(result).toMatchInlineSnapshot(`
 			{

src/index.test.ts

@@ -7,7 +7,7 @@
 	createTsonAsync,
 	tsonPromise,
 } from "./index.js";
-import { expectError, waitError, waitFor } from "./internals/testUtils.js";
+import { expectError, waitError, waitFor, createBodyStream } from "./internals/testUtils.js";
 import { TsonSerialized } from "./types.js";
 
 test("multiple handlers for primitive string found", () => {
@@ -95,7 +95,7 @@
 		const gen = generator();
 		await createTsonAsync({
 			types: [stringHandler, stringHandler],
-		}).parse(gen);
+		}).parse(createBodyStream(gen));
 	});
 
 	expect(err).toMatchInlineSnapshot(
@@ -136,7 +136,7 @@
 		const gen = generator();
 		await createTsonAsync({
 			types: [],
-		}).parse(gen);
+		}).parse(createBodyStream(gen));
 	});
 
 	expect(err).toMatchInlineSnapshot(
@@ -171,7 +171,7 @@
 	await createTsonAsync({
 		onStreamError: onErrorSpy,
 		types: [tsonPromise],
-	}).parse(generator());
+	}).parse(createBodyStream(generator()));
 
 	await waitFor(() => {
 		expect(onErrorSpy).toHaveBeenCalledTimes(1);

src/internals/testUtils.ts

@@ -72,3 +72,15 @@
 		url: `http://localhost:${port}`,
 	};
 }
+
+export function createBodyStream(iterator: AsyncIterable<string>) {
+	return new ReadableStream<Uint8Array>({
+		async start(controller) {
+			const encoder = new TextEncoder();
+			for await (const chunk of iterator) {
+				controller.enqueue(encoder.encode(chunk));
+			}
+			controller.close();
+		}
+	})
+}