Fix check for iterabile, improve coverage

.github/workflows/ci.yml

@@ -28,6 +28,8 @@ jobs:
         strategy:
             matrix:
                 node_version:
+                    - 14.17
+                    - 18.0
                     - 20
         steps:
             - uses: actions/checkout@v2
@@ -78,6 +80,7 @@ jobs:
                 node_version:
                     - 14.17.0
                     - 16
+                    - 18.0
                     - 18
                     - 20
                     - 22

src/parse-chunked.js

@@ -1,11 +1,9 @@
+import { isIterable } from './utils.js';
+
 const STACK_OBJECT = 1;
 const STACK_ARRAY = 2;
 const decoder = new TextDecoder();
 
-function isObject(value) {
-    return value !== null && typeof value === 'object';
-}
-
 function adjustPosition(error, parser) {
     if (error.name === 'SyntaxError' && parser.jsonParseOffset) {
         error.message = error.message.replace(/at position (\d+)/, (_, pos) =>
@@ -28,15 +26,15 @@ function append(array, elements) {
 }
 
 export async function parseChunked(chunkEmitter) {
-    const iterator = typeof chunkEmitter === 'function'
+    const iterable = typeof chunkEmitter === 'function'
         ? chunkEmitter()
         : chunkEmitter;
 
-    if (isObject(iterator) && (Symbol.iterator in iterator || Symbol.asyncIterator in iterator)) {
+    if (isIterable(iterable)) {
         let parser = new ChunkParser();
 
         try {
-            for await (const chunk of iterator) {
+            for await (const chunk of iterable) {
                 if (typeof chunk !== 'string' && !ArrayBuffer.isView(chunk)) {
                     throw new TypeError('Invalid chunk: Expected string, TypedArray or Buffer');
                 }
@@ -47,8 +45,6 @@ export async function parseChunked(chunkEmitter) {
             return parser.finish();
         } catch (e) {
             throw adjustPosition(e, parser);
-        } finally {
-            parser = null;
         }
     }
 

src/utils.js

@@ -1,4 +1,15 @@
-function replaceValue(holder, key, value, replacer) {
+export function isIterable(value) {
+    return (
+        typeof value === 'object' &&
+        value !== null &&
+        (
+            typeof value[Symbol.iterator] === 'function' ||
+            typeof value[Symbol.asyncIterator] === 'function'
+        )
+    );
+}
+
+export function replaceValue(holder, key, value, replacer) {
     if (value && typeof value.toJSON === 'function') {
         value = value.toJSON();
     }
@@ -26,7 +37,7 @@ function replaceValue(holder, key, value, replacer) {
     return value;
 }
 
-function normalizeReplacer(replacer) {
+export function normalizeReplacer(replacer) {
     if (typeof replacer === 'function') {
         return replacer;
     }
@@ -46,7 +57,7 @@ function normalizeReplacer(replacer) {
     return null;
 }
 
-function normalizeSpace(space) {
+export function normalizeSpace(space) {
     if (typeof space === 'number') {
         if (!Number.isFinite(space) || space < 1) {
             return false;
@@ -61,9 +72,3 @@ function normalizeSpace(space) {
 
     return false;
 }
-
-export {
-    replaceValue,
-    normalizeReplacer,
-    normalizeSpace
-};

src/web-streams.js

@@ -1,22 +1,23 @@
 /* eslint-env browser */
 import { parseChunked } from './parse-chunked.js';
 import { stringifyChunked } from './stringify-chunked.js';
+import { isIterable } from './utils.js';
 
 export function parseFromWebStream(stream) {
     // 2024/6/17: currently, an @@asyncIterator on a ReadableStream is not widely supported,
     // therefore use a fallback using a reader
     // https://caniuse.com/mdn-api_readablestream_--asynciterator
-    return parseChunked(stream && Symbol.asyncIterator in stream ? stream : async function*() {
+    return parseChunked(isIterable(stream) ? stream : async function*() {
         const reader = stream.getReader();
 
         while (true) {
-            const { done, chunk } = await reader.read();
+            const { value, done } = await reader.read();
 
             if (done) {
                 break;
             }
 
-            yield chunk;
+            yield value;
         }
     });
 }

test/parse-chunked.js

@@ -322,7 +322,9 @@ describe('parseChunked()', () => {
             () => ['[1, 2,', 3, ']'],
             () => 123,
             () => new Uint8Array([1, 2, 3]),
-            { on() {} }
+            { on() {} },
+            { [Symbol.iterator]: null },
+            { [Symbol.asyncIterator]: null }
         ];
 
         for (const value of badValues) {

test/web-streams.js

@@ -41,6 +41,15 @@ describeIfSupported('parseFromWebStream()', () => {
 
         assert.deepStrictEqual(actual, { foo: 123 });
     });
+
+    it('should parse ReadableStream with no @@asyncIterator', async () => {
+        const nonIterableReadableStream = Object.assign(createReadableStream(['{"foo', '":123', '}']), {
+            [Symbol.asyncIterator]: null
+        });
+        const actual = await parseFromWebStream(nonIterableReadableStream);
+
+        assert.deepStrictEqual(actual, { foo: 123 });
+    });
 });
 
 describeIfSupported('createStringifyWebStream()', () => {