From 0477e5320a87f88c133ccae59ee2372239da97a6 Mon Sep 17 00:00:00 2001
From: Yarchik <spoko.dev@gmail.com>
Date: Tue, 23 Jun 2026 23:33:41 +0100
Subject: [PATCH 1/2] fix: apply the encode callback to empty cookie values

The encode option is documented to mirror decode and should run for
every value, but stringifySetCookie used a truthiness test that skipped
it for the empty string, emitting a raw name= instead of the encoded
result. This broke encode/decode symmetry for signing and encrypting
encoders.

Use a null check so empty strings are routed through the encoder while
the object-form value: undefined still maps to an empty value. This
matches the sibling stringifyCookie helper and cookie@0.7.2, which both
always call the encoder.
---
 src/index.ts                     | 2 +-
 src/stringify-set-cookie.spec.ts | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/index.ts b/src/index.ts
index b30003f..4060207 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -304,7 +304,7 @@ export function stringifySetCookie(
     throw new TypeError(`argument name is invalid: ${name}`);
   }
 
-  const value = rawValue ? enc(rawValue) : "";
+  const value = rawValue != null ? enc(rawValue) : "";
 
   if (!cookieValueRegExp.test(value)) {
     throw new TypeError(`argument val is invalid: ${rawValue}`);
diff --git a/src/stringify-set-cookie.spec.ts b/src/stringify-set-cookie.spec.ts
index 92a56ea..8e8a719 100644
--- a/src/stringify-set-cookie.spec.ts
+++ b/src/stringify-set-cookie.spec.ts
@@ -127,6 +127,12 @@ describe("cookie.stringifySetCookie", function () {
       ).toEqual("foo=YmFy");
     });
 
+    it("should apply the encoder to an empty value", function () {
+      expect(
+        cookie.stringifySetCookie("foo", "", { encode: (v) => "[" + v + "]" }),
+      ).toEqual("foo=[]");
+    });
+
     it.each(["foo=bar", 'foo"bar', "foo,bar", "foo\\bar", "foo$bar"])(
       "should serialize value: %s",
       (value) => {

From 099ed03623338f055fe4598a17c16f0cca15da73 Mon Sep 17 00:00:00 2001
From: Blake Embrey <hello@blakeembrey.com>
Date: Wed, 24 Jun 2026 15:46:52 -0700
Subject: [PATCH 2/2] Fix test

---
 src/stringify-set-cookie.spec.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/stringify-set-cookie.spec.ts b/src/stringify-set-cookie.spec.ts
index 86c69c9..f4e9cd4 100644
--- a/src/stringify-set-cookie.spec.ts
+++ b/src/stringify-set-cookie.spec.ts
@@ -128,7 +128,10 @@ describe("cookie.stringifySetCookie", () => {
 
     it("should apply the encoder to an empty value", function () {
       expect(
-        cookie.stringifySetCookie("foo", "", { encode: (v) => "[" + v + "]" }),
+        stringifySetCookie(
+          { name: "foo", value: "" },
+          { encode: (v) => "[" + v + "]" },
+        ),
       ).toEqual("foo=[]");
     });