Backport #2965: Add a Request.cookies function

core/src/main/scala/org/http4s/Message.scala

@@ -338,6 +338,14 @@ sealed abstract case class Request[F[_]](
     */
   def params: Map[String, String] = uri.params
 
+  /**
+    * Parses all available [[Cookie]] headers into a list of [[RequestCookie]] objects. This
+    * implementation is compatible with cookie headers formatted per HTTP/1 and HTTP/2, or even both
+    * at the same time.
+    */
+  def cookies: List[RequestCookie] =
+    headers.get(Cookie).fold(List.empty[RequestCookie])(_.values.toList)
+
   /** Add a Cookie header for the provided [[Cookie]] */
   def addCookie(cookie: RequestCookie): Self =
     headers

tests/src/test/scala/org/http4s/MessageSpec.scala

@@ -126,6 +126,40 @@ class MessageSpec extends Http4sSpec {
       }
     }
 
+    "cookies" should {
+      val cookieList = List(
+        RequestCookie("test1", "value1"),
+        RequestCookie("test2", "value2"),
+        RequestCookie("test3", "value3"))
+
+      "be empty if there are no Cookie headers present" in {
+        Request(Method.GET).cookies mustEqual List.empty
+      }
+
+      "parse discrete HTTP/1 Cookie header(s) into corresponding RequestCookies" in {
+        val cookies = Header("Cookie", "test1=value1; test2=value2; test3=value3")
+        val request = Request(Method.GET, headers = Headers.of(cookies))
+        request.cookies mustEqual cookieList
+      }
+
+      "parse discrete HTTP/2 Cookie header(s) into corresponding RequestCookies" in {
+        val cookies = Headers.of(
+          Header("Cookie", "test1=value1"),
+          Header("Cookie", "test2=value2"),
+          Header("Cookie", "test3=value3"))
+        val request = Request(Method.GET, headers = cookies)
+        request.cookies mustEqual cookieList
+      }
+
+      "parse HTTP/1 and HTTP/2 Cookie headers on a single request into corresponding RequestCookies" in {
+        val cookies = Headers.of(
+          Header("Cookie", "test1=value1; test2=value2"), // HTTP/1 style
+          Header("Cookie", "test3=value3")) // HTTP/2 style (separate headers for separate cookies)
+        val request = Request(Method.GET, headers = cookies)
+        request.cookies mustEqual cookieList
+      }
+    }
+
     "toString" should {
       "redact an Authorization header" in {
         val request =