Merge pull request #285 from a-khakimov/hocon-list

Author: 2m

.gitignore

@@ -0,0 +1,4 @@
+/.idea/
+/project
+/target
+/.bsp/

README.md

@@ -47,16 +47,23 @@ val config = ConfigFactory.parseString("""
     |  elements = 2
     |  burst-duration = 100 millis
     |  check-interval = 2 weeks
+    |  values = [ first, second ]
     |}
   """.stripMargin)
 
-case class Rate(elements: Int, burstDuration: FiniteDuration, checkInterval: Period)
+case class Rate(
+  elements: Int,
+  burstDuration: FiniteDuration,
+  checkInterval: Period,
+  values: List[String]
+)
 
 val hocon = hoconAt(config)("rate")
 (
   hocon("elements").as[Int],
   hocon("burst-duration").as[FiniteDuration],
-  hocon("check-interval").as[Period]
+  hocon("check-interval").as[Period],
+  hocon("values").as[List[String]]
 ).parMapN(Rate.apply).load[IO].map { rate =>
   assertEquals(rate.burstDuration, 100.millis)
   assertEquals(rate.checkInterval, Period.ofWeeks(2))

src/main/scala/Hocon.scala

@@ -16,6 +16,7 @@
 
 package lt.dvim.ciris
 
+import scala.jdk.CollectionConverters._
 import scala.util.Try
 
 import ciris._
@@ -48,6 +49,18 @@ trait HoconConfigDecoders {
   implicit val stringHoconDecoder: ConfigDecoder[HoconConfigValue, String] =
     ConfigDecoder[HoconConfigValue].map(_.atKey("t").getString("t"))
 
+  implicit def listHoconDecoder[T](implicit
+      decoder: ConfigDecoder[HoconConfigValue, T]
+  ): ConfigDecoder[HoconConfigValue, List[T]] =
+    ConfigDecoder[HoconConfigValue]
+      .map(_.atKey("t").getList("t").asScala.toList)
+      .mapEither { (key, list) =>
+        list.map(decoder.decode(key, _)).partitionMap(identity) match {
+          case (Nil, rights)       => Right(rights)
+          case (firstLeft :: _, _) => Left(firstLeft)
+        }
+      }
+
   implicit val javaTimeDurationHoconDecoder: ConfigDecoder[HoconConfigValue, java.time.Duration] =
     ConfigDecoder[HoconConfigValue].map(_.atKey("t").getDuration("t"))
 

src/test/scala/HoconSpec.scala

@@ -31,6 +31,12 @@ class HoconSpec extends CatsEffectSuite {
       |    dur = 10 ms
       |    bool = true
       |    per = 2 weeks
+      |    listInt = [ 1, 2, 3, 4 ]
+      |    listString = [ a, b, c, d ]
+      |    listBool = [ true, false, true ]
+      |    listDouble = [ 1.12, 2.34, 2.33 ]
+      |    listDur = [ 10 ms, 15 ms, 1 s ]
+      |    invalidList = [ 1, a, true ]
       |  }
       |}
       |subst {
@@ -59,6 +65,43 @@ class HoconSpec extends CatsEffectSuite {
   test("parse Period") {
     nested("per").as[java.time.Period].load[IO] assertEquals java.time.Period.ofWeeks(2)
   }
+  test("parse List[Int]") {
+    nested("listInt").as[List[Int]].load[IO] assertEquals List(1, 2, 3, 4)
+  }
+  test("parse List[Long]") {
+    nested("listInt").as[List[Long]].load[IO] assertEquals List(1L, 2, 3, 4)
+  }
+  test("parse List[String]") {
+    nested("listString").as[List[String]].load[IO] assertEquals List("a", "b", "c", "d")
+  }
+  test("parse List[Bool]") {
+    nested("listBool").as[List[Boolean]].load[IO] assertEquals List(true, false, true)
+  }
+  test("parse List[Double]") {
+    nested("listDouble").as[List[Double]].load[IO] assertEquals List(1.12, 2.34, 2.33)
+  }
+  test("parse List[java Duration]") {
+    nested("listDur").as[List[java.time.Duration]].load[IO] assertEquals List(
+      java.time.Duration.ofMillis(10),
+      java.time.Duration.ofMillis(15),
+      java.time.Duration.ofSeconds(1)
+    )
+  }
+  test("parse List[scala Duration]") {
+    nested("listDur").as[List[FiniteDuration]].load[IO] assertEquals List(10.millis, 15.millis, 1.second)
+  }
+  test("handle decode error for invalid list") {
+    nested("invalidList")
+      .as[List[Int]]
+      .attempt[IO]
+      .map {
+        case Left(error) => error.messages.toList.head
+        case Right(_)    => "config loaded"
+      }
+      .assertEquals(
+        "Nested.config.invalidList with value a cannot be converted to Int"
+      )
+  }
   test("handle missing") {
     nested("missing")
       .as[Int]