Merge pull request #497 from Hydrospheredata/fix/default_arg_fix

arg with default value shouldn't ignore input value with invalid type

Author: dos65

mist-lib/src/main/scala/mist/api/UserArg.scala

@@ -1,6 +1,6 @@
 package mist.api
 
-import mist.api.data.JsMap
+import mist.api.data.{JsMap, JsNull}
 import mist.api.encoding.JsExtractor
 
 trait UserArg[A] extends ArgDef[A] { self =>
@@ -28,12 +28,18 @@ class NamedUserArg[A](name: String)(implicit ext: JsExtractor[A]) extends UserAr
   override def describe(): Seq[ArgInfo] = Seq(UserInputArgument(name, ext.`type`))
   override def extract(ctx: FnContext): Extraction[A] =
     ext.transformFailure(f => Failed.InvalidField(name, f))(ctx.params.fieldValue(name))
+
+  override def toString: String = s"${getClass.getSimpleName}($name)"
 }
 
 class NamedUserArgWithDefault[A](name: String, default: A)(implicit ext: JsExtractor[A]) extends UserArg[A] {
-  private val optExt = ext.orElse(default)
   override def describe(): Seq[ArgInfo] = Seq(UserInputArgument(name, MOption(ext.`type`)))
-  override def extract(ctx: FnContext): Extraction[A] =
-    optExt.transformFailure(f => Failed.InvalidField(name, f))(ctx.params.fieldValue(name))
+  override def extract(ctx: FnContext): Extraction[A] = {
+    ctx.params.fieldValue(name) match {
+      case JsNull => Extracted(default)
+      case x => ext.transformFailure(f => Failed.InvalidField(name, f))(x)
+    }
+  }
+  override def toString: String = s"${getClass.getSimpleName}($name, $default)"
 }
 

mist-lib/src/test/scala/mist/api/UserArgsSpec.scala

@@ -48,6 +48,7 @@ class UserArgsSpec extends FunSpec with Matchers {
       (arg[Boolean]("b"),        JsMap("b" -> true.js),  Extracted(true)),
       (arg[Boolean]("b", false), JsMap.empty,            Extracted(false)),
       (arg[Boolean]("b", true),  JsMap("b" -> false.js), Extracted(false)),
+      (arg[Boolean]("c", true),  JsMap("c" -> "2".js),   failed),
       (arg[Boolean]("b"),        JsMap.empty,            failed),
       (arg[Option[Boolean]]("b"),JsMap("b" -> true.js),  Extracted(Some(true))),
       (arg[Option[Boolean]]("b"),JsMap.empty,            Extracted(None)),