EmptyFileTest: use explicit expected

scalafmt-tests/src/test/scala/org/scalafmt/EmptyFileTest.scala

@@ -1,16 +1,27 @@
 package org.scalafmt
 
+import scala.meta.internal.prettyprinters.DoubleQuotes
+
 import java.lang.System.lineSeparator
 
 import munit.FunSuite
 
 class EmptyFileTest extends FunSuite {
 
-  test("empty tree formats to newline") {
-    Seq("", lineSeparator, "", s"   $lineSeparator  ").foreach { original =>
-      val expected = "\n"
+  Seq(
+    ("", "\n"),
+    ("  \n  \n  ", "\n"),
+    ("  \r\n  \r\n  ", "\n"),
+    (lineSeparator(), "\n"),
+    (s"   $lineSeparator  ", "\n"),
+  ).foreach { case (original, expected) =>
+    val expectedQuoted = DoubleQuotes(expected)
+    test(s"empty tree formats to newline: ${DoubleQuotes(original)} -> $expectedQuoted") {
       val obtained = Scalafmt.format(original).get
-      assertNoDiff(obtained, expected)
+      if (obtained != expected) fail(
+        s"values are not equal: ${DoubleQuotes(obtained)} != $expectedQuoted",
+      )
     }
   }
+
 }