Incorrect overloading resolution involving parameterless method

[liufengyun]

This is encountered when working with ScalaTest test set.

minimized code

trait StringTempl {
  def mkString: String
  def mkString(x: String): String
}


object Test {
  def (x: String) shouldBe(y: String): Boolean = ???

  def test(tmpl: StringTempl): Unit = {
    tmpl.mkString shouldBe "hello"                       // error
    tmpl.mkString(", world") shouldBe "hello, world"
  }
}

The compiler reports an error:

-- [E134] Type Mismatch Error: examples/apply.scala:11:9 -----------------------
11 |    tmpl.mkString shouldBe "hello"
   |    ^^^^^^^^^^^^^
   |None of the overloaded alternatives of method mkString in trait StringTempl with types
   | (x: String): String
   | => String
   |match expected type ?{ shouldBe: ? }

expectation

The compiler should accept the code without reporting an error.