From 8ee7ffeea619459a028e5eaaf78b1e3af1e2e201 Mon Sep 17 00:00:00 2001
From: Phil Pluckthun <phil@kitten.sh>
Date: Sun, 1 Feb 2026 23:02:55 +0000
Subject: [PATCH] fix: Premature callback in `InflateStream` before flush (#25)

---
 .changeset/tender-planes-brush.md | 5 +++++
 src/encoding.ts                   | 4 +++-
 2 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/tender-planes-brush.md

diff --git a/.changeset/tender-planes-brush.md b/.changeset/tender-planes-brush.md
new file mode 100644
index 0000000..f7f74df
--- /dev/null
+++ b/.changeset/tender-planes-brush.md
@@ -0,0 +1,5 @@
+---
+'fetch-nodeshim': patch
+---
+
+Fix `_final` on `InflateStream` calling `callback` before full flush.
diff --git a/src/encoding.ts b/src/encoding.ts
index aa3a141..8b1fc1c 100644
--- a/src/encoding.ts
+++ b/src/encoding.ts
@@ -37,10 +37,12 @@ class InflateStream extends Transform {
 
   _final(callback: TransformCallback) {
     if (this._inflate) {
+      this._inflate.once('finish', callback);
       this._inflate.end();
       this._inflate = undefined;
+    } else {
+      callback();
     }
-    callback();
   }
 }
 
-- 
2.51.2