From 62033caa4831a3128e56a75a873bdcc91d1903e0 Mon Sep 17 00:00:00 2001
From: Daniel Huigens <d.huigens@protonmail.com>
Date: Mon, 26 May 2025 15:47:54 +0200
Subject: [PATCH] Add `consumeToEnd` convenience function

Similar to `readToEnd`, but discard the data.
---
 lib/index.d.ts |  2 ++
 lib/reader.js  | 12 ++++++++++++
 lib/streams.js | 15 +++++++++++++++
 lib/writer.js  |  4 ++++
 4 files changed, 33 insertions(+)

diff --git a/lib/index.d.ts b/lib/index.d.ts
index d13110e..967d61c 100644
--- a/lib/index.d.ts
+++ b/lib/index.d.ts
@@ -13,6 +13,8 @@ export function readToEnd<T extends Data, JoinFn extends (chunks: T[]) => any =
   join?: JoinFn
 ): Promise<ReturnType<JoinFn>>;
 
+export function consumeToEnd<T extends Data>(input: MaybeStream<T>): Promise<undefined>;
+
 export function toStream<T extends Data, InputType extends MaybeStream<T>>(
   input: InputType
 ): InputType extends T ? Stream<InputType> : InputType;
diff --git a/lib/reader.js b/lib/reader.js
index a61ceb5..264f2dc 100644
--- a/lib/reader.js
+++ b/lib/reader.js
@@ -204,4 +204,16 @@ Reader.prototype.readToEnd = async function(join=streams.concat) {
   return join(result);
 };
 
+/**
+ * Consume the entire stream and wait until it ends.
+ * @async
+ */
+Reader.prototype.consumeToEnd = async function() {
+  // eslint-disable-next-line no-constant-condition
+  while (true) {
+    const { done } = await this.read();
+    if (done) break;
+  }
+};
+
 export { Reader, externalBuffer };
diff --git a/lib/streams.js b/lib/streams.js
index 591eee2..2fd4b30 100644
--- a/lib/streams.js
+++ b/lib/streams.js
@@ -499,6 +499,20 @@ async function readToEnd(input, join=concat) {
   return input;
 }
 
+/**
+ * Consume a stream to the end. Throws if the input stream errors.
+ * @param {ReadableStream|Uint8array|String} input
+ * @async
+ */
+async function consumeToEnd(input) {
+  if (isArrayStream(input)) {
+    return input.consumeToEnd();
+  }
+  if (isStream(input)) {
+    return getReader(input).consumeToEnd();
+  }
+}
+
 /**
  * Cancel a stream.
  * @param {ReadableStream|Uint8array|String} input
@@ -576,6 +590,7 @@ export {
   passiveClone,
   slice,
   readToEnd,
+  consumeToEnd,
   cancel,
   fromAsync
 };
diff --git a/lib/writer.js b/lib/writer.js
index 24edd89..d72e94e 100644
--- a/lib/writer.js
+++ b/lib/writer.js
@@ -40,6 +40,10 @@ ArrayStream.prototype.readToEnd = async function(join) {
   return result;
 };
 
+ArrayStream.prototype.consumeToEnd = async function() {
+  await this[doneWritingPromise];
+};
+
 ArrayStream.prototype.clone = function() {
   const clone = new ArrayStream();
   clone[doneWritingPromise] = this[doneWritingPromise].then(() => {