From e0afff8a0e538a7c4504e8f238a5f0ead8740a5e Mon Sep 17 00:00:00 2001
From: Koert Kuipers <koert@tresata.com>
Date: Tue, 10 May 2022 10:07:54 -0400
Subject: [PATCH] allow option to wrap something thats repeatable and keep it
 repeatable

---
 mainargs/src/TokensReader.scala        | 21 ++++++++++++++++-----
 mainargs/test/src/OptionSeqTests.scala | 21 +++++++++++++++++++++
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/mainargs/src/TokensReader.scala b/mainargs/src/TokensReader.scala
index 064d3a1..6c70b13 100644
--- a/mainargs/src/TokensReader.scala
+++ b/mainargs/src/TokensReader.scala
@@ -21,14 +21,25 @@ object TokensReader{
   implicit def OptionRead[T: TokensReader]: TokensReader[Option[T]] = new TokensReader[Option[T]](
     implicitly[TokensReader[T]].shortName,
     strs => {
-      strs.lastOption match{
-        case None => Right(None)
-        case Some(s) => implicitly[TokensReader[T]].read(Seq(s)) match{
-          case Left(s) =>Left(s)
-          case Right(s) => Right(Some(s))
+      if (implicitly[TokensReader[T]].alwaysRepeatable) {
+        Option(strs).filter(_.nonEmpty) match{
+          case None => Right(None)
+          case Some(strs) => implicitly[TokensReader[T]].read(strs) match{
+            case Left(s) => Left(s)
+            case Right(s) => Right(Some(s))
+          }
+        }
+      } else {
+        strs.lastOption match{
+          case None => Right(None)
+          case Some(s) => implicitly[TokensReader[T]].read(Seq(s)) match{
+            case Left(s) => Left(s)
+            case Right(s) => Right(Some(s))
+          }
         }
       }
     },
+    alwaysRepeatable = implicitly[TokensReader[T]].alwaysRepeatable,
     allowEmpty = true
   )
   implicit def SeqRead[C[_] <: Iterable[_], T: TokensReader](implicit factory: Factory[T, C[T]]): TokensReader[C[T]] = new TokensReader[C[T]](
diff --git a/mainargs/test/src/OptionSeqTests.scala b/mainargs/test/src/OptionSeqTests.scala
index 30af766..6a45ee9 100644
--- a/mainargs/test/src/OptionSeqTests.scala
+++ b/mainargs/test/src/OptionSeqTests.scala
@@ -18,6 +18,9 @@ object OptionSeqTests extends TestSuite{
 
     @main
     def runInt(int: Int) = int
+
+    @main
+    def runOptionSeq(os: Option[Seq[Int]]) = os
   }
 
   val tests = Tests {
@@ -42,6 +45,24 @@ object OptionSeqTests extends TestSuite{
           Seq(123)
       }
     }
+
+    test("option seq") {
+      test {
+        ParserForMethods(Main).runOrThrow(Array("runOptionSeq", "--os", "123")) ==>
+          Some(Seq(123))
+      }
+
+      test {
+        ParserForMethods(Main).runOrThrow(Array("runOptionSeq", "--os", "123", "--os", "456")) ==>
+          Some(Seq(123, 456))
+      }
+
+      test {
+        ParserForMethods(Main).runOrThrow(Array("runOptionSeq")) ==>
+          None
+      }
+    }
+
     test("vec"){
       ParserForMethods(Main).runOrThrow(Array("runVec", "--seq", "123", "--seq", "456")) ==>
         Vector(123, 456)