From 5060b26935b30da9b224e43b2eb24269cccf10ff Mon Sep 17 00:00:00 2001
From: Vadim Chelyshov <qtankle@gmail.com>
Date: Tue, 27 Dec 2022 18:36:19 +0300
Subject: [PATCH] fix: workaround for empty completion list + `isIncomplete =
 true` (#1278)

If Vscode receives emptuy completion list it ignores `isIncomplete` field.
Fixes: https://github.com/scalameta/metals/issues/4756

Vscode issue: https://github.com/microsoft/vscode/issues/155738
---
 src/extension.ts | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/extension.ts b/src/extension.ts
index 7b5071bee..535f57bc0 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -29,6 +29,8 @@ import {
   Hover,
   TextDocument,
   tests as vscodeTextExplorer,
+  CompletionItem,
+  CompletionList,
 } from "vscode";
 import {
   LanguageClient,
@@ -301,6 +303,28 @@ function launchMetals(
     outputChannel: outputChannel,
     initializationOptions,
     middleware: {
+      provideCompletionItem: async (
+        document,
+        position,
+        context,
+        token,
+        next
+      ) => {
+        const list = await next(document, position, context, token);
+        if (Array.isArray(list)) {
+          return list;
+        } else if (list) {
+          // workaround for https://github.com/scalameta/metals/issues/4756
+          // original vscode issue https://github.com/microsoft/vscode/issues/155738
+          if (list.isIncomplete && list.items.length == 0) {
+            // this item won't be rendered by vscode
+            const item = new CompletionItem("type more!!");
+            return new CompletionList([item], true);
+          } else {
+            return list;
+          }
+        }
+      },
       provideHover: hoverLinksMiddlewareHook,
     },
     markdown: {