fix: cookies() .set() reflect priority attribute into set-cookie (#640)

Co-authored-by: Balázs Orbán <info@balazsorban.com>

.changeset/fifty-eagles-invite.md

@@ -0,0 +1,5 @@
+---
+'@edge-runtime/cookies': patch
+---
+
+fix cookies() .set() to reflect the priority attribute into set-cookie

packages/cookies/src/serialize.ts

@@ -14,6 +14,7 @@ export function stringifyCookie(c: ResponseCookie | RequestCookie): string {
     'secure' in c && c.secure && 'Secure',
     'httpOnly' in c && c.httpOnly && 'HttpOnly',
     'sameSite' in c && c.sameSite && `SameSite=${c.sameSite}`,
+    'priority' in c && c.priority && `Priority=${c.priority}`,
   ].filter(Boolean)
 
   return `${c.name}=${encodeURIComponent(c.value ?? '')}; ${attrs.join('; ')}`
@@ -54,10 +55,18 @@ export function parseSetCookie(setCookie: string): undefined | ResponseCookie {
   }
 
   const [[name, value], ...attributes] = parseCookie(setCookie)
-  const { domain, expires, httponly, maxage, path, samesite, secure } =
-    Object.fromEntries(
-      attributes.map(([key, value]) => [key.toLowerCase(), value]),
-    )
+  const {
+    domain,
+    expires,
+    httponly,
+    maxage,
+    path,
+    samesite,
+    secure,
+    priority,
+  } = Object.fromEntries(
+    attributes.map(([key, value]) => [key.toLowerCase(), value]),
+  )
   const cookie: ResponseCookie = {
     name,
     value: decodeURIComponent(value),
@@ -68,6 +77,7 @@ export function parseSetCookie(setCookie: string): undefined | ResponseCookie {
     path,
     ...(samesite && { sameSite: parseSameSite(samesite) }),
     ...(secure && { secure: true }),
+    ...(priority && { priority: parsePriority(priority) }),
   }
 
   return compact(cookie)
@@ -91,3 +101,12 @@ function parseSameSite(string: string): ResponseCookie['sameSite'] {
     ? (string as ResponseCookie['sameSite'])
     : undefined
 }
+
+const PRIORITY: ResponseCookie['priority'][] = ['low', 'medium', 'high']
+
+function parsePriority(string: string): ResponseCookie['priority'] {
+  string = string.toLowerCase()
+  return PRIORITY.includes(string as any)
+    ? (string as ResponseCookie['priority'])
+    : undefined
+}

packages/cookies/test/response-cookies.test.ts

@@ -64,6 +64,25 @@ test('reflect .set into `set-cookie`', async () => {
   )
 })
 
+it('reflect .set all options attributes into `set-cookie`', async () => {
+  const headers = new Headers()
+  const cookies = new ResponseCookies(headers)
+  cookies.set('first-name', 'first-value', {
+    domain: 'custom-domain',
+    path: 'custom-path',
+    secure: true,
+    sameSite: 'strict',
+    expires: new Date(2100, 0, 1, 12, 0, 0),
+    httpOnly: true,
+    maxAge: 0,
+    priority: 'high',
+  })
+  const cookiesInHeaders = Object.fromEntries(headers.entries())['set-cookie']
+  expect(cookiesInHeaders).toBe(
+    'first-name=first-value; Path=custom-path; Expires=Fri, 01 Jan 2100 12:00:00 GMT; Max-Age=0; Domain=custom-domain; Secure; HttpOnly; SameSite=strict; Priority=high',
+  )
+})
+
 describe('`set-cookie` into .get and .getAll', () => {
   test.each([
     'name=value; Secure; HttpOnly',