feat: add priority to serializer

cookie.js

@@ -152,6 +152,26 @@ function serialize (name, val, opt) {
     str += '; Path=' + opt.path
   }
 
+  if (opt.priority) {
+    const priority = typeof opt.priority === 'string'
+      ? opt.priority.toLowerCase()
+      : opt.priority
+
+    switch (priority) {
+      case 'low':
+        str += '; Priority=Low'
+        break
+      case 'medium':
+        str += '; Priority=Medium'
+        break
+      case 'high':
+        str += '; Priority=High'
+        break
+      default:
+        throw new TypeError('option priority is invalid')
+    }
+  }
+
   if (opt.expires) {
     if (typeof opt.expires.toUTCString !== 'function') {
       throw new TypeError('option expires is invalid')

test/cookie-module.test.js

@@ -203,3 +203,21 @@ test('unencoded', (t) => {
   }), /argument val is invalid/)
   t.end()
 })
+
+test('serializer: priority', (t) => {
+  t.plan(8)
+  t.same(cookie.serialize('foo', 'bar', { priority: 'Low' }), 'foo=bar; Priority=Low')
+  t.same(cookie.serialize('foo', 'bar', { priority: 'low' }), 'foo=bar; Priority=Low')
+  t.same(cookie.serialize('foo', 'bar', { priority: 'Medium' }), 'foo=bar; Priority=Medium')
+  t.same(cookie.serialize('foo', 'bar', { priority: 'medium' }), 'foo=bar; Priority=Medium')
+  t.same(cookie.serialize('foo', 'bar', { priority: 'High' }), 'foo=bar; Priority=High')
+  t.same(cookie.serialize('foo', 'bar', { priority: 'high' }), 'foo=bar; Priority=High')
+
+  t.throws(cookie.serialize.bind(cookie, 'foo', 'bar', {
+    priority: 'foo'
+  }), /option priority is invalid/)
+  t.throws(cookie.serialize.bind(cookie, 'foo', 'bar', {
+    priority: true
+  }), /option priority is invalid/)
+  t.end()
+})

types/plugin.d.ts

@@ -115,18 +115,21 @@ declare namespace fastifyCookie {
     domain?: string;
     /** Specifies a function that will be used to encode a cookie's value. Since value of a cookie has a limited character set (and must be a simple string), this function can be used to encode a value into a string suited for a cookie's value. */
     encode?(val: string): string;
-    /**  The expiration `date` used for the `Expires` attribute. If both `expires` and `maxAge` are set, then `expires` is used. */
+    /** The expiration `date` used for the `Expires` attribute. If both `expires` and `maxAge` are set, then `expires` is used. */
     expires?: Date;
-    /**  The `boolean` value of the `HttpOnly` attribute. Defaults to true. */
+    /** The `boolean` value of the `HttpOnly` attribute. Defaults to true. */
     httpOnly?: boolean;
-    /**  A `number` in seconds that specifies the `Expires` attribute by adding the specified seconds to the current date. If both `expires` and `maxAge` are set, then `expires` is used. */
+    /** A `number` in seconds that specifies the `Expires` attribute by adding the specified seconds to the current date. If both `expires` and `maxAge` are set, then `expires` is used. */
     maxAge?: number;
+    /** A `boolean` indicating whether the cookie is tied to the top-level site where it's initially set and cannot be accessed from elsewhere. */
     partitioned?: boolean;
-    /**  The `Path` attribute. Defaults to `/` (the root path).  */
+    /** The `Path` attribute. Defaults to `/` (the root path).  */
     path?: string;
     /** A `boolean` or one of the `SameSite` string attributes. E.g.: `lax`, `none` or `strict`.  */
     sameSite?: 'lax' | 'none' | 'strict' | boolean;
-    /**  The `boolean` value of the `Secure` attribute. Set this option to false when communicating over an unencrypted (HTTP) connection. Value can be set to `auto`; in this case the `Secure` attribute will be set to false for HTTP request, in case of HTTPS it will be set to true.  Defaults to true. */
+    /** One of the `Priority` string attributes ()`low`, `medium` or `high`) specifying a retention priority for HTTP cookies that will be respected by user agents during cookie eviction. */
+    priority?: 'low' | 'medium' | 'high';
+    /** The `boolean` value of the `Secure` attribute. Set this option to false when communicating over an unencrypted (HTTP) connection. Value can be set to `auto`; in this case the `Secure` attribute will be set to false for HTTP request, in case of HTTPS it will be set to true.  Defaults to true. */
     secure?: boolean;
   }