stream: add a non-destroying iterator to Readable

add a non-destroying iterator to Readable

fixes: https://github.com/nodejs/node/issues/38491

PR-URL: https://github.com/nodejs/node/pull/38526
Fixes: https://github.com/nodejs/node/issues/38491
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

1 files changed, 116 insertions, 0 deletions

diff --git a/test/parallel/test-stream-readable-async-iterators.js b/test/parallel/test-stream-readable-async-iterators.js
index 7c457fdc3da..a497317565f 100644
--- a/test/parallel/test-stream-readable-async-iterators.js
+++ b/test/parallel/test-stream-readable-async-iterators.js
@@ -693,6 +693,122 @@ async function tests() {
   });
 }
 
+// AsyncIterator non-destroying iterator
+{
+  function createReadable() {
+    return Readable.from((async function* () {
+      await Promise.resolve();
+      yield 5;
+      await Promise.resolve();
+      yield 7;
+      await Promise.resolve();
+    })());
+  }
+
+  function createErrorReadable() {
+    const opts = { read() { throw new Error('inner'); } };
+    return new Readable(opts);
+  }
+
+  // Check default destroys on return
+  (async function() {
+    const readable = createReadable();
+    for await (const chunk of readable.iterator()) {
+      assert.strictEqual(chunk, 5);
+      break;
+    }
+
+    assert.ok(readable.destroyed);
+  })().then(common.mustCall());
+
+  // Check explicit destroying on return
+  (async function() {
+    const readable = createReadable();
+    for await (const chunk of readable.iterator({ destroyOnReturn: true })) {
+      assert.strictEqual(chunk, 5);
+      break;
+    }
+
+    assert.ok(readable.destroyed);
+  })().then(common.mustCall());
+
+  // Check default destroys on error
+  (async function() {
+    const readable = createErrorReadable();
+    try {
+      // eslint-disable-next-line no-unused-vars
+      for await (const chunk of readable) { }
+      assert.fail('should have thrown');
+    } catch (err) {
+      assert.strictEqual(err.message, 'inner');
+    }
+
+    assert.ok(readable.destroyed);
+  })().then(common.mustCall());
+
+  // Check explicit destroys on error
+  (async function() {
+    const readable = createErrorReadable();
+    const opts = { destroyOnError: true, destroyOnReturn: false };
+    try {
+      // eslint-disable-next-line no-unused-vars
+      for await (const chunk of readable.iterator(opts)) { }
+      assert.fail('should have thrown');
+    } catch (err) {
+      assert.strictEqual(err.message, 'inner');
+    }
+
+    assert.ok(readable.destroyed);
+  })().then(common.mustCall());
+
+  // Check explicit non-destroy with return true
+  (async function() {
+    const readable = createErrorReadable();
+    const opts = { destroyOnError: false, destroyOnReturn: true };
+    try {
+      // eslint-disable-next-line no-unused-vars
+      for await (const chunk of readable.iterator(opts)) { }
+      assert.fail('should have thrown');
+    } catch (err) {
+      assert.strictEqual(err.message, 'inner');
+    }
+
+    assert.ok(!readable.destroyed);
+  })().then(common.mustCall());
+
+  // Check explicit non-destroy with return true
+  (async function() {
+    const readable = createReadable();
+    const opts = { destroyOnReturn: false };
+    for await (const chunk of readable.iterator(opts)) {
+      assert.strictEqual(chunk, 5);
+      break;
+    }
+
+    assert.ok(!readable.destroyed);
+
+    for await (const chunk of readable.iterator(opts)) {
+      assert.strictEqual(chunk, 7);
+    }
+
+    assert.ok(readable.destroyed);
+  })().then(common.mustCall());
+
+  // Check non-object options.
+  {
+    const readable = createReadable();
+    assert.throws(
+      () => readable.iterator(42),
+      {
+        code: 'ERR_INVALID_ARG_TYPE',
+        name: 'TypeError',
+        message: 'The "options" argument must be of type object. Received ' +
+                 'type number (42)',
+      }
+    );
+  }
+}
+
 {
   let _req;
   const server = http.createServer((request, response) => {