From 82a8b3b34f2d5c25c8f45135200a7b9a8a1d6369 Mon Sep 17 00:00:00 2001
From: Mark Stuart <mstuart@users.noreply.github.com>
Date: Sat, 17 Oct 2026 22:24:15 +0000
Subject: [PATCH] fix: close zero-length take streams immediately

---
 index.js           |  5 +++++
 readme.md          |  2 ++
 regression.test.js | 20 ++++++++++++++++++++
 3 files changed, 27 insertions(+)
 create mode 100644 regression.test.js

diff --git a/index.js b/index.js
index dc2b9b6..c7ffcfa 100644
--- a/index.js
+++ b/index.js
@@ -41,6 +41,11 @@ export function takeStream(count) {
 
   let taken = 0;
   return new TransformStream({
+    start(controller) {
+      if (count === 0) {
+        controller.terminate();
+      }
+    },
     transform(chunk, controller) {
       if (taken < count) {
         taken += 1;
diff --git a/readme.md b/readme.md
index 3b90303..b362015 100644
--- a/readme.md
+++ b/readme.md
@@ -44,6 +44,8 @@ Returns a `TransformStream` that only passes chunks where `function_` returns `t
 
 ### takeStream(count)
 
+A count of zero closes the readable side immediately, without waiting for upstream data.
+
 Returns a `TransformStream` that passes only the first `count` chunks then terminates.
 
 ### batchStream(size)
diff --git a/regression.test.js b/regression.test.js
new file mode 100644
index 0000000..3bd1136
--- /dev/null
+++ b/regression.test.js
@@ -0,0 +1,20 @@
+import test from "ava";
+import { takeStream } from "./index.js";
+
+test("takeStream(0) closes without waiting for an upstream chunk", async (t) => {
+  const transform = takeStream(0);
+  const reader = transform.readable.getReader();
+  let timeout;
+  try {
+    const result = await Promise.race([
+      reader.read(),
+      new Promise((resolve) => {
+        timeout = setTimeout(() => resolve("still pending"), 100);
+      }),
+    ]);
+    t.deepEqual(result, { done: true, value: undefined });
+  } finally {
+    clearTimeout(timeout);
+    await reader.cancel();
+  }
+});