fix: don't suggest completions for param names in definition (#6620)

Author: kasiaMarek

mtags/src/main/scala-3/scala/meta/internal/pc/completions/Completions.scala

@@ -527,6 +527,9 @@ class Completions(
       case Literal(Constant(null)) :: tl =>
         advancedCompletions(tl, pos, completionPos)
 
+      // def foo(a@@)
+      case ParamDefinitionCompletions(allowKeywords) =>
+        (ParamDefinitionCompletions.contribute(allowKeywords, completionPos), true)
       case _ =>
         val args = NamedArgCompletions.contribute(
           pos,

mtags/src/main/scala-3/scala/meta/internal/pc/completions/ParamDefinitionCompletions.scala

@@ -0,0 +1,23 @@
+package scala.meta.internal.pc.completions
+
+import dotty.tools.dotc.ast.tpd.*
+import dotty.tools.dotc.core.Contexts.Context
+
+object ParamDefinitionCompletions:
+  private val possibleKeywords = List("using", "implicit")
+  private def completion(keyword: String) = CompletionValue.keyword(keyword, keyword ++ " ")
+
+  def unapply(path: List[Tree])(using Context): Option[Boolean] =
+    path match
+      case (vd: ValDef) :: (d : DefDef) :: _ =>
+        d.paramss.lastOption.map(_.indexWhere(_.span.contains(vd.span))).filter(_ >= 0)
+         match
+          case Some(ind) if ind == 0 => Some(true)
+          case Some(_) => Some(false)
+          case _ => None
+      case _ => None
+
+  def contribute(allowKeywords: Boolean, pos: CompletionPos): List[CompletionValue] =
+    if allowKeywords
+    then possibleKeywords.filter(_.startsWith(pos.query)).map(completion)
+    else Nil

tests/cross/src/test/scala/tests/pc/CompletionKeywordSuite.scala

@@ -574,92 +574,17 @@ class CompletionKeywordSuite extends BaseCompletionSuite {
        |  def hello(u@@)
        |}""".stripMargin,
     """|using (commit: '')
-       |unsafeExceptions scala (commit: '')
-       |unchecked scala (commit: '')
-       |unsafeNulls - scala.runtime.stdLibPatches.language (commit: '')
-       |unshared(): unshared (commit: '')""".stripMargin,
+       |""".stripMargin,
     includeCommitCharacter = true,
-    compat = Map(
-      "2" -> "",
-      "3.3.0" -> """|using (commit: '')
-                    |unsafeExceptions scala (commit: '')
-                    |unchecked scala (commit: '')
-                    |unsafe - scala.caps (commit: '')
-                    |unsafeNulls - scala.runtime.stdLibPatches.language (commit: '')
-                    |""".stripMargin,
-      "3.3.1" -> """|using (commit: '')
-                    |unsafeExceptions scala (commit: '')
-                    |unchecked scala (commit: '')
-                    |unsafe - scala.caps (commit: '')
-                    |unsafeNulls - scala.runtime.stdLibPatches.language (commit: '')
-                    |""".stripMargin,
-      "3.3.3" -> """|using (commit: '')
-                    |unsafeExceptions scala (commit: '')
-                    |unchecked scala (commit: '')
-                    |unsafe - caps (commit: '')
-                    |unsafeNulls - scala.runtime.stdLibPatches.language (commit: '')
-                    |""".stripMargin,
-      "3.4" -> """|using (commit: '')
-                  |unsafeExceptions scala (commit: '')
-                  |unchecked scala (commit: '')
-                  |unsafe - scala.caps (commit: '')
-                  |unsafeNulls - scala.runtime.stdLibPatches.language (commit: '')
-                  |""".stripMargin,
-      ">=3.4.1-RC1-bin-20240201-hash-NIGHTLY" ->
-        """|using (commit: '')
-           |unsafe - scala.caps (commit: '')
-           |unsafeNulls - scala.runtime.stdLibPatches.language (commit: '')
-           |unused - scala.annotation (commit: '')
-           |unshared - scala.annotation.internal (commit: '')
-           |""".stripMargin,
-      ">=3.4.2-RC1-bin-20240301-hash-NIGHTLY" -> "using (commit: '')"
-    ),
-    topLines = Some(5)
+    compat = Map("2" -> "")
   )
 
   check(
     "not-using",
     """|object A{
        |  def hello(a: String, u@@)
        |}""".stripMargin,
-    "",
-    compat = Map(
-      "3" -> """|unsafeExceptions scala
-                |unchecked scala
-                |unsafeNulls - scala.runtime.stdLibPatches.language
-                |unshared(): unshared
-                |uncheckedStable(): uncheckedStable""".stripMargin,
-      "3.3.0" -> """|unsafeExceptions scala
-                    |unchecked scala
-                    |unsafe - scala.caps
-                    |unsafeNulls - scala.runtime.stdLibPatches.language
-                    |unshared(): unshared""".stripMargin,
-      "3.3.1" -> """|unsafeExceptions scala
-                    |unchecked scala
-                    |unsafe - scala.caps
-                    |unsafeNulls - scala.runtime.stdLibPatches.language
-                    |unshared(): unshared""".stripMargin,
-      "3.3.3" -> """|unsafeExceptions scala
-                    |unchecked scala
-                    |unsafe - caps
-                    |unsafeNulls - scala.runtime.stdLibPatches.language
-                    |unshared(): unshared""".stripMargin,
-      "3.4" -> """|unsafeExceptions scala
-                  |unchecked scala
-                  |unsafe - scala.caps
-                  |unsafeNulls - scala.runtime.stdLibPatches.language
-                  |unused - scala.annotation
-                  |""".stripMargin,
-      ">=3.4.1-RC1-bin-20240201-hash-NIGHTLY" ->
-        """|unsafe - scala.caps
-           |unsafeNulls - scala.runtime.stdLibPatches.language
-           |unused - scala.annotation
-           |unshared - scala.annotation.internal
-           |unspecialized - scala.annotation
-           |""".stripMargin,
-      ">=3.4.2-RC1-bin-20240301-hash-NIGHTLY" -> ""
-    ),
-    topLines = Some(5)
+    ""
   )
 
   check(

tests/cross/src/test/scala/tests/pc/CompletionSuite.scala

@@ -2368,4 +2368,17 @@ class CompletionSuite extends BaseCompletionSuite {
     itemIndex = 1
   )
 
+  check(
+    "def-arg",
+    """|package a
+       |object W {
+       |  val aaaaaa = 1
+       |}
+       |object O {
+       |  def foo(aa@@)
+       |}
+       |""".stripMargin,
+    ""
+  )
+
 }