fix(ext/fetch): `Body#bodyUsed` for static body (#16080)

This fixes a bug where `Body#bodyUsed` incorrectly returns `false`
for a body that has actually already been consumed, after `Body#body`
is called.

3 files changed, 24 insertions, 0 deletions

diff --git a/cli/tests/unit/response_test.ts b/cli/tests/unit/response_test.ts
index c46218b62..c2a230138 100644
--- a/cli/tests/unit/response_test.ts
+++ b/cli/tests/unit/response_test.ts
@@ -90,3 +90,13 @@ Deno.test(function customInspectFunction() {
   );
   assertStringIncludes(Deno.inspect(Response.prototype), "Response");
 });
+
+Deno.test(async function responseBodyUsed() {
+  const response = new Response("body");
+  assert(!response.bodyUsed);
+  await response.text();
+  assert(response.bodyUsed);
+  // .body getter is needed so we can test the faulty code path
+  response.body;
+  assert(response.bodyUsed);
+});
diff --git a/ext/fetch/22_body.js b/ext/fetch/22_body.js
index 97a8a8db1..6e9a57447 100644
--- a/ext/fetch/22_body.js
+++ b/ext/fetch/22_body.js
@@ -28,6 +28,8 @@
   const {
     isReadableStreamDisturbed,
     errorReadableStream,
+    readableStreamClose,
+    readableStreamDisturb,
     createProxy,
     ReadableStreamPrototype,
   } = globalThis.__bootstrap.streams;
@@ -92,6 +94,8 @@
         if (consumed) {
           this.streamOrStatic = new ReadableStream();
           this.streamOrStatic.getReader();
+          readableStreamDisturb(this.streamOrStatic);
+          readableStreamClose(this.streamOrStatic);
         } else {
           this.streamOrStatic = new ReadableStream({
             start(controller) {
diff --git a/ext/web/06_streams.js b/ext/web/06_streams.js
index bd1714964..bd3b79149 100644
--- a/ext/web/06_streams.js
+++ b/ext/web/06_streams.js
@@ -1153,6 +1153,15 @@
     reader[_closedPromise].resolve(undefined);
   }
 
+  /**
+   * @template R
+   * @param {ReadableStream<R>} stream
+   * @returns {void}
+   */
+  function readableStreamDisturb(stream) {
+    stream[_disturbed] = true;
+  }
+
   /** @param {ReadableStreamDefaultController<any>} controller */
   function readableStreamDefaultControllerCallPullIfNeeded(controller) {
     const shouldPull = readableStreamDefaultcontrollerShouldCallPull(
@@ -5910,6 +5919,7 @@
     createProxy,
     writableStreamClose,
     readableStreamClose,
+    readableStreamDisturb,
     readableStreamForRid,
     getReadableStreamRid,
     Deferred,