fix(ext/http): correctly consume response body in `Deno.serve` (#24811)

Prior to this commit, you could return a `Response` created from a
string or Uint8Array multiple times.

Now you can't do that anymore.

1 files changed, 11 insertions, 0 deletions

diff --git a/ext/http/00_serve.ts b/ext/http/00_serve.ts
index a58d19d76..8ed1a1d04 100644
--- a/ext/http/00_serve.ts
+++ b/ext/http/00_serve.ts
@@ -436,6 +436,11 @@ function fastSyncResponseOrStream(
 
   const stream = respBody.streamOrStatic;
   const body = stream.body;
+  if (body !== undefined) {
+    // We ensure the response has not been consumed yet in the caller of this
+    // function.
+    stream.consumed = true;
+  }
 
   if (TypedArrayPrototypeGetSymbolToStringTag(body) === "Uint8Array") {
     innerRequest?.close();
@@ -505,6 +510,12 @@ function mapToCallback(context, callback, onError) {
           "Return value from serve handler must be a response or a promise resolving to a response",
         );
       }
+
+      if (response.bodyUsed) {
+        throw TypeError(
+          "The body of the Response returned from the serve handler has already been consumed.",
+        );
+      }
     } catch (error) {
       try {
         response = await onError(error);