Address Ian's feedback

http4s/src/main/scala/com.snowplowanalytics.snowplow.collectors.scalastream/CollectorService.scala

@@ -190,17 +190,12 @@ class CollectorService[F[_]: Sync](
         case None =>
           cookieConfig.map { config =>
             val responseCookie = ResponseCookie(
-              name    = config.name,
-              content = networkUserId,
-              expires = Some(HttpDate.unsafeFromEpochSecond((now + config.expiration).toSeconds)),
-              domain  = cookieDomain(headers, config.domains, config.fallbackDomain),
-              path    = Some("/"),
-              sameSite = config.sameSite.flatMap {
-                case "Strict" => SameSite.Strict.some
-                case "Lax"    => SameSite.Lax.some
-                case "None"   => SameSite.None.some
-                case _        => None
-              },
+              name     = config.name,
+              content  = networkUserId,
+              expires  = Some(HttpDate.unsafeFromEpochSecond((now + config.expiration).toSeconds)),
+              domain   = cookieDomain(headers, config.domains, config.fallbackDomain),
+              path     = Some("/"),
+              sameSite = config.sameSite,
               secure   = config.secure,
               httpOnly = config.httpOnly
             )
@@ -222,14 +217,15 @@ class CollectorService[F[_]: Sync](
     */
   def cookieDomain(
     headers: Headers,
-    domains: Option[List[String]],
+    domains: List[String],
     fallbackDomain: Option[String]
   ): Option[String] =
-    (for {
-      domainList <- domains
-      originHosts = extractHosts(headers)
-      domainToUse <- domainList.find(domain => originHosts.exists(validMatch(_, domain)))
-    } yield domainToUse).orElse(fallbackDomain)
+    (domains match {
+      case Nil => None
+      case _ =>
+        val originHosts = extractHosts(headers)
+        domains.find(domain => originHosts.exists(validMatch(_, domain)))
+    }).orElse(fallbackDomain)
 
   /** Extracts the host names from a list of values in the request's Origin header. */
   def extractHosts(headers: Headers): List[String] =

http4s/src/main/scala/com.snowplowanalytics.snowplow.collectors.scalastream/model.scala

@@ -2,6 +2,8 @@ package com.snowplowanalytics.snowplow.collectors.scalastream
 
 import scala.concurrent.duration._
 
+import org.http4s.SameSite
+
 import io.circe.Json
 
 object model {
@@ -33,11 +35,11 @@ object model {
     enabled: Boolean,
     name: String,
     expiration: FiniteDuration,
-    domains: Option[List[String]],
+    domains: List[String],
     fallbackDomain: Option[String],
     secure: Boolean,
     httpOnly: Boolean,
-    sameSite: Option[String]
+    sameSite: Option[SameSite]
   )
 
   final case class CollectorConfig(

http4s/src/test/scala/com.snowplowanalytics.snowplow.collectors.scalastream/CollectorServiceSpec.scala

@@ -258,7 +258,7 @@ class CollectorServiceSpec extends Specification {
         enabled        = true,
         name           = "name",
         expiration     = 5.seconds,
-        domains        = Some(List("domain")),
+        domains        = List("domain"),
         fallbackDomain = None,
         secure         = false,
         httpOnly       = false,
@@ -325,7 +325,7 @@ class CollectorServiceSpec extends Specification {
         val conf = testCookieConfig.copy(
           secure   = true,
           httpOnly = true,
-          sameSite = Some("None")
+          sameSite = Some(SameSite.None)
         )
         val Some(`Set-Cookie`(cookie)) =
           service.cookieHeader(
@@ -356,7 +356,7 @@ class CollectorServiceSpec extends Specification {
         enabled        = true,
         name           = "name",
         expiration     = 5.seconds,
-        domains        = None,
+        domains        = List.empty,
         fallbackDomain = None,
         secure         = false,
         httpOnly       = false,
@@ -370,7 +370,7 @@ class CollectorServiceSpec extends Specification {
         }
         "if a list of domains is supplied in the config but the Origin request header is empty and there is no fallback domain" in {
           val headers      = Headers.empty
-          val cookieConfig = testCookieConfig.copy(domains = Some(List("domain.com")))
+          val cookieConfig = testCookieConfig.copy(domains = List("domain.com"))
           service.cookieDomain(headers, cookieConfig.domains, cookieConfig.fallbackDomain) shouldEqual None
         }
         "if none of the domains in the request's Origin header has a match in the list of domains supplied with the config and there is no fallback domain" in {
@@ -383,7 +383,7 @@ class CollectorServiceSpec extends Specification {
           )
           val headers = Headers(origin.toRaw1)
           val cookieConfig = testCookieConfig.copy(
-            domains = Some(List("domain.com", "otherdomain.com"))
+            domains = List("domain.com", "otherdomain.com")
           )
           service.cookieDomain(headers, cookieConfig.domains, cookieConfig.fallbackDomain) shouldEqual None
         }
@@ -401,7 +401,7 @@ class CollectorServiceSpec extends Specification {
         "if the Origin header is empty and a fallback domain is configured" in {
           val headers = Headers.empty
           val cookieConfig = testCookieConfig.copy(
-            domains        = Some(List("domain.com")),
+            domains        = List("domain.com"),
             fallbackDomain = Some("fallbackDomain")
           )
           service.cookieDomain(headers, cookieConfig.domains, cookieConfig.fallbackDomain) shouldEqual Some(
@@ -418,7 +418,7 @@ class CollectorServiceSpec extends Specification {
           )
           val headers = Headers(origin.toRaw1)
           val cookieConfig = testCookieConfig.copy(
-            domains        = Some(List("domain.com", "otherdomain.com")),
+            domains        = List("domain.com", "otherdomain.com"),
             fallbackDomain = Some("fallbackDomain")
           )
           service.cookieDomain(headers, cookieConfig.domains, cookieConfig.fallbackDomain) shouldEqual Some(
@@ -435,7 +435,7 @@ class CollectorServiceSpec extends Specification {
           )
           val headers = Headers(origin.toRaw1)
           val cookieConfig = testCookieConfig.copy(
-            domains        = Some(List("domain.com", "otherdomain.com")),
+            domains        = List("domain.com", "otherdomain.com"),
             fallbackDomain = Some("fallbackDomain")
           )
           service.cookieDomain(headers, cookieConfig.domains, cookieConfig.fallbackDomain) shouldEqual Some(
@@ -456,7 +456,7 @@ class CollectorServiceSpec extends Specification {
           )
           val headers = Headers(origin.toRaw1)
           val cookieConfig = testCookieConfig.copy(
-            domains        = Some(List("domain.com", "otherdomain.com")),
+            domains        = List("domain.com", "otherdomain.com"),
             fallbackDomain = Some("fallbackDomain")
           )
           service.cookieDomain(headers, cookieConfig.domains, cookieConfig.fallbackDomain) shouldEqual Some(

http4s/src/test/scala/com.snowplowanalytics.snowplow.collectors.scalastream/TestUtils.scala

@@ -15,7 +15,7 @@ object TestUtils {
       enabled        = true,
       name           = "sp",
       expiration     = 365.days,
-      domains        = None,
+      domains        = List.empty,
       fallbackDomain = None,
       secure         = false,
       httpOnly       = false,

stdout/src/main/scala/com.snowplowanalytics.snowplow.collectors.scalastream/StdoutCollector.scala

@@ -34,7 +34,7 @@ object StdoutCollector extends IOApp {
           enabled        = true,
           name           = "sp",
           expiration     = 365.days,
-          domains        = None,
+          domains        = List.empty,
           fallbackDomain = None,
           secure         = false,
           httpOnly       = false,