Fix empty list of holes not being published (#1027)

Author: timsueberkrueb

effekt/jvm/src/main/scala/effekt/Server.scala

@@ -182,7 +182,6 @@ class Server(config: EffektConfig, compileOnChange: Boolean=false) extends Langu
   def publishHoles(source: Source, config: EffektConfig)(implicit C: Context): Unit = {
     if (!workspaceService.settingBool("showHoles")) return
     val holes = getHoles(source)
-    if (holes.isEmpty) return
     client.publishHoles(EffektPublishHolesParams(source.name, holes.map(EffektHoleInfo.fromHoleInfo)))
   }
 

effekt/jvm/src/test/scala/effekt/LSPTests.scala

@@ -1390,6 +1390,27 @@ class LSPTests extends FunSuite {
     assertEquals(actualJson, expectedJson)
   }
 
+  test("Empty holes list is sent when there are no holes") {
+    withClientAndServer { (client, server) =>
+      val source =
+        raw"""
+             |def foo(x: Int): Int = x + 1
+             |""".textDocument
+
+      val initializeParams = new InitializeParams()
+      val initializationOptions = """{"showHoles": true}"""
+      initializeParams.setInitializationOptions(JsonParser.parseString(initializationOptions))
+      server.initialize(initializeParams).get()
+
+      val didOpenParams = new DidOpenTextDocumentParams()
+      didOpenParams.setTextDocument(source)
+      server.getTextDocumentService().didOpen(didOpenParams)
+
+      val receivedHoles = client.receivedHoles()
+      assertEquals(receivedHoles.length, 1)
+      assert(receivedHoles.head.holes.isEmpty)
+    }
+  }
 
   // Text document DSL
   //