From f0839587a2db6cf82796fd040bd9d4871135f692 Mon Sep 17 00:00:00 2001
From: satorg <satorg@gmail.com>
Date: Wed, 12 Aug 2020 00:59:31 -0700
Subject: [PATCH] add `Obfuscated.fromString`; improve `Element`

---
 .../scala/org/http4s/headers/Forwarded.scala  | 38 +++++++++++++++++--
 .../http4s/parser/ForwardedModelParsing.scala | 14 ++++++-
 .../org/http4s/headers/ForwardedSpec.scala    | 15 ++++++++
 3 files changed, 63 insertions(+), 4 deletions(-)

diff --git a/core/src/main/scala/org/http4s/headers/Forwarded.scala b/core/src/main/scala/org/http4s/headers/Forwarded.scala
index 6f6516674e3..739e4b00292 100644
--- a/core/src/main/scala/org/http4s/headers/Forwarded.scala
+++ b/core/src/main/scala/org/http4s/headers/Forwarded.scala
@@ -23,7 +23,7 @@ object Forwarded
   object Node {
     def apply(nodeName: Name, nodePort: Port): Node = apply(nodeName, Some(nodePort))
 
-    sealed trait Name
+    sealed trait Name { _: Product => }
 
     object Name {
       final case class Ipv4(address: Uri.Ipv4Address) extends Name
@@ -40,7 +40,7 @@ object Forwarded
           : Name = apply(Uri.Ipv6Address(a, b, c, d, e, f, g, h))
     }
 
-    sealed trait Port
+    sealed trait Port { _: Product => }
 
     object Port {
       final case class Num(value: Int) extends Port
@@ -52,7 +52,26 @@ object Forwarded
         }
     }
 
-    final case class Obfuscated(value: String) extends Name with Port
+    sealed trait Obfuscated extends Name with Port { _: Product =>
+
+      /**
+        * Obfuscated value doesn't include the leading underscore symbol.
+        */
+      def value: String
+    }
+    object Obfuscated {
+      def fromString(s: String): ParseResult[Obfuscated] =
+        new ModelNodeObfuscatedValueParser(s).parse.map(apply)
+
+      def unapply(o: Obfuscated): Option[String] = Some(o.value)
+
+      // Referenced by model parsers.
+      private[http4s] def apply(s: String): Obfuscated = C(s)
+
+      private[this] final case class C(value: String) extends Obfuscated {
+        override def productPrefix: String = "Obfuscated"
+      }
+    }
 
     def fromString(s: String): ParseResult[Node] = new ModelNodeParser(s).parse
   }
@@ -78,6 +97,11 @@ object Forwarded
     def withFor(value: Node): Element
     def withHost(value: Host): Element
     def withProto(value: Proto): Element
+
+    def withoutBy: Element
+    def withoutFor: Element
+    def withoutHost: Element
+    def withoutProto: Element
   }
 
   /**
@@ -101,6 +125,11 @@ object Forwarded
       def withHost(value: Host): Element = copy(`host` = Some(value))
       def withProto(value: Proto): Element = copy(`proto` = Some(value))
 
+      def withoutBy: Element = copy(`by` = None)
+      def withoutFor: Element = copy(`for` = None)
+      def withoutHost: Element = copy(`host` = None)
+      def withoutProto: Element = copy(`proto` = None)
+
       override def productPrefix: String = "Element"
     }
 
@@ -108,6 +137,9 @@ object Forwarded
     def withFor(value: Node): Element = C(`for` = Some(value))
     def withHost(value: Host): Element = C(`host` = Some(value))
     def withProto(value: Proto): Element = C(`proto` = Some(value))
+
+    def unapply(elem: Element): Option[(Option[Node], Option[Node], Option[Host], Option[Proto])] =
+      Some((elem.`by`, elem.`for`, elem.`host`, elem.`proto`))
   }
 
   override def parse(s: String): ParseResult[Forwarded] = HttpHeaderParser.FORWARDED(s)
diff --git a/core/src/main/scala/org/http4s/parser/ForwardedModelParsing.scala b/core/src/main/scala/org/http4s/parser/ForwardedModelParsing.scala
index 1ca1597bec7..4ce3bcfdb3c 100644
--- a/core/src/main/scala/org/http4s/parser/ForwardedModelParsing.scala
+++ b/core/src/main/scala/org/http4s/parser/ForwardedModelParsing.scala
@@ -46,9 +46,14 @@ private[http4s] trait ForwardedModelParsing { model: Forwarded.type =>
         } | ModelNodeObfuscated
       }
 
+    protected final def ModelNodeObfuscatedValue: Rule1[String] =
+      rule {
+        capture(oneOrMore(AlphaNum | '.' | '_' | '-'))
+      }
+
     protected final def ModelNodeObfuscated: Rule1[model.Node.Obfuscated] =
       rule {
-        '_' ~ capture(oneOrMore(AlphaNum | '.' | '_' | '-')) ~> model.Node.Obfuscated
+        '_' ~ ModelNodeObfuscatedValue ~> { model.Node.Obfuscated(_: String) }
       }
 
     protected final def ModelHost: Rule1[model.Host] =
@@ -64,6 +69,13 @@ private[http4s] trait ForwardedModelParsing { model: Forwarded.type =>
     override def main: Rule1[Node] = rule(ModelNode ~ EOI)
   }
 
+  protected final class ModelNodeObfuscatedValueParser(s: String)
+      extends Http4sParser[String](s, "invalid obfuscated value")
+      with ModelParsers {
+
+    override def main: Rule1[String] = rule(ModelNodeObfuscatedValue ~ EOI)
+  }
+
   protected final class ModelHostParser(s: String)
       extends Http4sParser[model.Host](s, "invalid host")
       with ModelParsers {
diff --git a/tests/src/test/scala/org/http4s/headers/ForwardedSpec.scala b/tests/src/test/scala/org/http4s/headers/ForwardedSpec.scala
index 8c9457a9262..7f7c2460dfb 100644
--- a/tests/src/test/scala/org/http4s/headers/ForwardedSpec.scala
+++ b/tests/src/test/scala/org/http4s/headers/ForwardedSpec.scala
@@ -64,6 +64,21 @@ class ForwardedSpec extends Specification with Tables {
       }
     }
   }
+  "Node.Obfuscated" >> {
+    import Forwarded.Node.Obfuscated
+
+    "parse valid obfuscated values" in {
+      val validValues = Seq(
+        "1",
+        "a",
+        "_"
+      )
+
+      Result.foreach(validValues) { value =>
+        Obfuscated.fromString(value) must beRight((_: Obfuscated).value must_=== value)
+      }
+    }
+  }
   "Host" >> {
     import Forwarded.Host