using assert(x.size(1) == 3) in a test, triggers a wrong compiler warning

[jimka2001]

When I compile the code belo using scalatest 2.3.15 in scala version 2.13.10, I get an annoying and wrong warning. Could it be that assert is expanding to code which contains something.size without the parens?

Auto-application to `()` is deprecated. Supply the empty argument list `()` explicitly to invoke method size,
or remove the empty argument list from its definition (Java-defined methods are exempt).
In Scala 3, an unapplied method like this will be eta-expanded into a function.
    assert(MyObj.size() == 3) // how to get rid of this warning?

import org.scalatest.funsuite.AnyFunSuite

object MyObj  {

  def size():Int = {
    3
  }
}

class MyTestSuite2 extends AnyFunSuite {
  test("test3") {
    ()
  }
  test("size") {
    assert(MyObj.size() == 3) // how to get rid of this warning?
  }
}

[bvenners]

@jimka2001 That is possible. We'll check into it. For now to get rid of the warning you can use Predef.assert instead of ScalaTest's assert:

  Predef.assert(MyObj.size() == 3)

[som-snytt]

With -Vmacro, the missing application is evident at $org_scalatest_assert_macro_left.size. I added the WARN output to make sure what was tested, as the macro output is copious.

It would also be nice if the expansion preserved positions so the error message caret is in the correct column.

macroImplArgs: List(Expr[Nothing](MyObj.size().==(3)), Expr[Nothing](scalactic.this.Prettifier.default), Expr[Nothing]((Position.apply("ParenTest.scala", "Please set the environment variable SCALACTIC_FILL_FILE_PATHNAMES to yes at compile time to enable this feature.", 9): org.scalactic.source.Position)))
typechecking {
  val $org_scalatest_assert_macro_expr = {
    val $org_scalatest_assert_macro_left = MyObj;
    val $org_scalatest_assert_macro_right = 3;
    _root_.org.scalactic.Bool.lengthSizeMacroBool($org_scalatest_assert_macro_left, "size", $org_scalatest_assert_macro_left.size, $org_scalatest_assert_macro_right, scalactic.this.Prettifier.default)
  };
  _root_.org.scalatest.Assertions.assertionsHelper.macroAssert($org_scalatest_assert_macro_expr, "", scalactic.this.Prettifier.default, (Position.apply("ParenTest.scala", "Please set the environment variable SCALACTIC_FILL_FILE_PATHNAMES to yes at compile time to enable this feature.", 9): org.scalactic.source.Position))
} with expected type ?, implicit views = true, macros = true
WARN on $org_scalatest_assert_macro_left.size
{
  val $org_scalatest_assert_macro_expr: org.scalactic.Bool = {
    val $org_scalatest_assert_macro_left: MyObj.type = MyObj;
    val $org_scalatest_assert_macro_right: Int = 3;
    org.scalactic.Bool.lengthSizeMacroBool($org_scalatest_assert_macro_left, "size", $org_scalatest_assert_macro_left.size(), $org_scalatest_assert_macro_right, scalactic.this.Prettifier.default)
  };
  org.scalatest.Assertions.assertionsHelper.macroAssert($org_scalatest_assert_macro_expr, "", scalactic.this.Prettifier.default, (Position.apply("ParenTest.scala", "Please set the environment variable SCALACTIC_FILL_FILE_PATHNAMES to yes at compile time to enable this feature.", 9): org.scalactic.source.Position))
}

[cheeseng]

@jimka2001 @som-snytt @bvenners I submitted the following PR for this problem:

#2230

Thanks for reporting it!

[som-snytt]

Thanks! And they say never call a plumber on the weekend.

[som-snytt]

The PR was merged, ticket should be closed.