Reproduce #1594

modules/bootstrapped/src/generated/smithy4s/example/HasConstrainedNewtype.scala

@@ -0,0 +1,22 @@
+package smithy4s.example
+
+import smithy4s.Hints
+import smithy4s.Schema
+import smithy4s.ShapeId
+import smithy4s.ShapeTag
+import smithy4s.schema.Schema.struct
+
+final case class HasConstrainedNewtype(s: CityId)
+
+object HasConstrainedNewtype extends ShapeTag.Companion[HasConstrainedNewtype] {
+  val id: ShapeId = ShapeId("smithy4s.example", "HasConstrainedNewtype")
+
+  val hints: Hints = Hints.empty
+
+  // constructor using the original order from the spec
+  private def make(s: CityId): HasConstrainedNewtype = HasConstrainedNewtype(s)
+
+  implicit val schema: Schema[HasConstrainedNewtype] = struct(
+    CityId.schema.validated(smithy.api.Length(min = Some(1L), max = None)).required[HasConstrainedNewtype]("s", _.s),
+  )(make).withId(id).addHints(hints)
+}

modules/codegen/src/smithy4s/codegen/internals/ModelLoader.scala

@@ -51,7 +51,7 @@ private[codegen] object ModelLoader {
     val modelsInJars = deps.flatMap { file =>
       Using.resource(
         // Note: On JDK13+, the second parameter is redundant.
-        FileSystems.newFileSystem(file.toPath(), null)
+        FileSystems.newFileSystem(file.toPath(), null: ClassLoader)
       ) { jarFS =>
         val p = jarFS.getPath("META-INF", "smithy", "manifest")
 

sampleSpecs/memberConstraints.smithy

@@ -14,3 +14,9 @@ map ConstrainedMap {
     value: String
 }
 
+// Regression test for https://github.com/disneystreaming/smithy4s/issues/1594
+structure HasConstrainedNewtype {
+    @length(min: 1)
+    @required
+    s: CityId
+}