Support multiple renames for the same symbol

Author: Duhemm

compiler/src/dotty/tools/dotc/interactive/Completion.scala

@@ -335,18 +335,22 @@ object Completion {
     *  in the REPL and the IDE.
     */
    private class RenameAwareScope extends Scopes.MutableScope {
-     private[this] val renames: mutable.Map[Symbol, Name] = mutable.Map.empty
+     private[this] val renames: mutable.Map[Symbol, List[Name]] = mutable.Map.empty
 
      /** Enter the symbol `sym` in this scope, recording a potential renaming. */
      def enter[T <: Symbol](sym: T, name: Name)(implicit ctx: Context): T = {
-       if (name != sym.name) renames += sym -> name
+       renames += sym -> (name :: renames.getOrElse(sym, Nil))
        newScopeEntry(name, sym)
        sym
      }
 
      /** Lists the symbols in this scope along with the name associated with them. */
-     def toListWithNames(implicit ctx: Context): List[(Symbol, Name)] =
-       toList.map(sym => (sym, renames.get(sym).getOrElse(sym.name)))
+     def toListWithNames(implicit ctx: Context): List[(Symbol, Name)] = {
+       for {
+         sym <- toList
+         name <- renames.getOrElse(sym, List(sym.name))
+       } yield (sym, name)
+     }
    }
 
 }

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

@@ -214,4 +214,26 @@ class CompletionTest {
            }""".withSource
       .completion(m1, Set(("MyImportedSymbol", Class, "java.io.FileDescriptor")))
   }
+
+  @Test def completionRenamedAndOriginalNames: Unit = {
+    code"""import java.util.HashMap
+          |trait Foo {
+          |  import java.util.{HashMap => HashMap2}
+          |  val x: Hash$m1
+          |}""".withSource
+      .completion(m1, Set(("HashMap", Class, "java.util.HashMap"),
+                          ("HashMap2", Class, "java.util.HashMap")))
+  }
+
+  @Test def completionRenamedThrice: Unit = {
+    code"""import java.util.{HashMap => MyHashMap}
+          |import java.util.{HashMap => MyHashMap2}
+          |trait Foo {
+          |  import java.util.{HashMap => MyHashMap3}
+          |  val x: MyHash$m1
+          |}""".withSource
+      .completion(m1, Set(("MyHashMap", Class, "java.util.HashMap"),
+                          ("MyHashMap2", Class, "java.util.HashMap"),
+                          ("MyHashMap3", Class, "java.util.HashMap")))
+  }
 }