add opaque type for env data

VirtusLab · Oct 2, 2024 · 3ef2b44 · 3ef2b44
1 parent ffbae83
commit 3ef2b44
Show file tree

Hide file tree

Showing 2 changed files with 15 additions and 14 deletions.
diff --git a/besom-cfg/lib/src/main/scala/Configured.scala b/besom-cfg/lib/src/main/scala/Configured.scala
@@ -8,9 +8,6 @@ import scala.util.control.NoStackTrace
 
 final val Version = "0.4.0-SNAPSHOT"
 
-implicit val envDefault: Default[Map[String, String]] = new Default[Map[String, String]]:
-  def default: Map[String, String] = sys.env
-
 // trait Constraint[A]:
 //   def validate(a: A): Boolean
 //   def &(other: Constraint[A]): Constraint[A] =
@@ -53,13 +50,17 @@ trait Configured[A]:
 object Configured:
 
   trait FromEnv[A] extends Configured[A]:
-    type INPUT = Map[String, String]
-    def schema: Schema
-    def newInstance(input: INPUT): A
+    type INPUT = FromEnv.EnvData
 
   object FromEnv:
     val MediumIdentifier = "env"
 
+    opaque type EnvData >: Map[String, String] = Map[String, String]
+    extension (env: EnvData) def unwrap: Map[String, String] = env
+    object EnvData:
+      given Default[EnvData] = new Default[EnvData]:
+        def default: EnvData = sys.env
+
     inline def derived[A <: Product]: Configured.FromEnv[A] = ${ derivedImpl[A] }
 
     def derivedImpl[A <: Product: Type](using ctx: Quotes): Expr[Configured.FromEnv[A]] =
@@ -92,12 +93,10 @@ object Configured:
         new Configured.FromEnv[A] {
 
           def schema = $schemaExpr
-          def newInstance(input: Map[String, String]): A =
-            $fromEnvExpr.decode(input, from.env.EnvPath.Root) match
+          def newInstance(input: INPUT): A =
+            $fromEnvExpr.decode(input.unwrap, from.env.EnvPath.Root) match
               case Validated.Valid(a)        => a
               case Validated.Invalid(errors) => throw ConfigurationError(errors.toVector)
-
-          def default(using Default[INPUT]): INPUT = summon[Default[INPUT]].default
         }
       }
     end derivedImpl

diff --git a/besom-cfg/lib/src/test/scala/ConfiguredTest.scala b/besom-cfg/lib/src/test/scala/ConfiguredTest.scala
@@ -1,5 +1,7 @@
 package besom.cfg
 
+import besom.cfg.Configured.FromEnv
+
 case class Test1(los: List[String]) derives Configured.FromEnv
 
 case class Test2(name: String, int: Int, struct: First, list: List[Double]) derives Configured.FromEnv
@@ -101,8 +103,8 @@ class ConfiguredTest extends munit.FunSuite:
   val env = Map("los.0" -> "test", "los.1" -> "test2").withBesomCfgPrefix
 
   test("resolve configuration - use default") {
-    given Default[Map[String, String]] = new Default[Map[String, String]]:
-      def default: Map[String, String] = env
+    given Default[FromEnv.EnvData] = new Default[FromEnv.EnvData]:
+      def default: FromEnv.EnvData = env
 
     try
       resolveConfiguration[Test1] match
@@ -124,8 +126,8 @@ class ConfiguredTest extends munit.FunSuite:
   }
 
   test("resolve configuration - use default and either variant") {
-    given Default[Map[String, String]] = new Default[Map[String, String]]:
-      def default: Map[String, String] = env
+    given Default[FromEnv.EnvData] = new Default[FromEnv.EnvData]:
+      def default: FromEnv.EnvData = env
 
       resolveConfigurationEither[Test1] match
         case Right(Test1(los)) =>