Workaround missing complitions due to non-backportable change in the upstream. Update CompletionTests

Author: WojciechMazur

language-server/test/dotty/tools/languageserver/CompletionTest.scala

@@ -1659,7 +1659,7 @@ class CompletionTest {
            |""".completion(m1, Set(
              ("Number", Field, "scala.util.matching.Regex"),
              ("NumberFormatException", Module, "NumberFormatException"),
-             ("Numeric", Field, "scala.math.Numeric")
+             ("Numeric", Method, "=> scala.math.Numeric.type")
            ))
 
   @Test def shadowedImportType: Unit =
@@ -1677,6 +1677,6 @@ class CompletionTest {
              ("NumberFormatException", Module, "NumberFormatException"),
              ("NumberFormatException", Field, "NumberFormatException"),
              ("Numeric", Field, "Numeric"),
-             ("Numeric", Field, "scala.math.Numeric")
+             ("Numeric", Method, "=> scala.math.Numeric.type")
            ))
 }

presentation-compiler/src/main/dotty/tools/pc/completions/Completions.scala

@@ -233,9 +233,11 @@ class Completions(
   ): List[CompletionValue] =
     val sym = denot.symbol
     // find the apply completion that would need a snippet
+    // <accessor> handling is LTS specific: It's a workaround to mittigate lack of https://github.com/scala/scala3/pull/18874 backport
+    // which was required in backport of https://github.com/scala/scala3/pull/18914 to achive the improved completions semantics.
     val methodDenots: List[SingleDenotation] =
       if shouldAddSnippet && completionMode.is(Mode.Term) &&
-        (sym.is(Flags.Module) || sym.isField || sym.isClass && !sym.is(Flags.Trait)) && !sym.is(Flags.JavaDefined)
+        (sym.isOneOf(Flags.Module | Flags.Accessor) || sym.isField || sym.isClass && !sym.is(Flags.Trait)) && !sym.is(Flags.JavaDefined)
       then
         val info =
           /* Companion will be added even for normal classes now,