Moved Method Does Not Take (More) Parameters error to case class

compiler/src/dotty/tools/dotc/reporting/diagnostic/ErrorMessageID.java

@@ -57,6 +57,7 @@ public enum ErrorMessageID {
     CyclicReferenceInvolvingImplicitID,
     SuperQualMustBeParentID,
     AmbiguousImportID,
+    MethodDoesNotTakeParametersId,
     AmbiguousOverloadID,
     ReassignmentToValID,
     ;

compiler/src/dotty/tools/dotc/reporting/diagnostic/messages.scala

@@ -1251,6 +1251,30 @@ object messages {
            |"""
   }
 
+  case class MethodDoesNotTakeParameters(tree: tpd.Tree, methPartType: Types.Type)(err: typer.ErrorReporting.Errors)(implicit ctx: Context)
+  extends Message(MethodDoesNotTakeParametersId) {
+    private val more = tree match {
+      case Apply(_, _) => " more"
+      case _ => ""
+    }
+
+    val msg = hl"${err.refStr(methPartType)} does not take$more parameters"
+
+    val kind = "Reference"
+
+    private val noParameters = if (methPartType.widenSingleton.isInstanceOf[ExprType])
+      hl"""|As ${err.refStr(methPartType)} is defined without parenthesis, you may
+           |not use any at call-site, either.
+           |"""
+    else
+      ""
+
+    val explanation =
+      s"""|You have specified more parameter lists as defined in the method definition(s).
+          |$noParameters""".stripMargin
+
+  }
+
   case class AmbiguousOverload(tree: tpd.Tree, alts: List[SingleDenotation], pt: Type)(
     err: typer.ErrorReporting.Errors)(
     implicit ctx: Context)
@@ -1283,5 +1307,4 @@ object messages {
            |  ${"var"} $name ${"="} ...
            |""".stripMargin
   }
-
 }

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -1834,11 +1834,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
         else
           tree
       case _ => tryInsertApplyOrImplicit(tree, pt) {
-        val more = tree match {
-          case Apply(_, _) => " more"
-          case _ => ""
-        }
-        errorTree(tree, em"$methodStr does not take$more parameters")
+        errorTree(tree, MethodDoesNotTakeParameters(tree, methPart(tree).tpe)(err))
       }
     }
 

compiler/test/dotty/tools/dotc/reporting/ErrorMessagesTests.scala

@@ -360,6 +360,46 @@ class ErrorMessagesTests extends ErrorMessagesTest {
         assertEquals(namedImport, prevPrec)
       }
 
+  @Test def methodDoesNotTakePrameters =
+    checkMessagesAfter("frontend") {
+      """
+        |object Scope{
+        |  def foo = ()
+        |  foo()
+        |}
+      """.stripMargin
+    }
+    .expect { (ictx, messages) =>
+      implicit val ctx: Context = ictx
+      val defn = ictx.definitions
+
+      assertMessageCount(1, messages)
+      val MethodDoesNotTakeParameters(tree, methodPart) :: Nil = messages
+
+      assertEquals("Scope.foo", tree.show)
+      assertEquals("=> Unit(Scope.foo)", methodPart.show)
+    }
+
+  @Test def methodDoesNotTakeMorePrameters =
+    checkMessagesAfter("frontend") {
+      """
+        |object Scope{
+        |  def foo(a: Int) = ()
+        |  foo(1)("2")
+        |}
+      """.stripMargin
+    }
+    .expect { (ictx, messages) =>
+      implicit val ctx: Context = ictx
+      val defn = ictx.definitions
+
+      assertMessageCount(1, messages)
+      val MethodDoesNotTakeParameters(tree, methodPart) :: Nil = messages
+
+      assertEquals("Scope.foo(1)", tree.show)
+      assertEquals("((a: Int)Unit)(Scope.foo)", methodPart.show)
+    }
+
   @Test def ambiugousOverloadWithWildcard =
     checkMessagesAfter("frontend") {
       """object Context {