From a15739371779e3ea6c0303c4e958e0575c06ac9e Mon Sep 17 00:00:00 2001
From: Riatre Foo <foo@riat.re>
Date: Tue, 9 Oct 2018 23:38:05 +0800
Subject: [PATCH] Fix additionalTextEdits -> textEdit hack for VS Code

Visual Studio Code filters the completion result according to
textEdit.range and filterText, if the textEdit.range overlaps with
existing text, we have to include it in filterText, otherwise it would
be filtered out.
---
 src/messages/textDocument_completion.cc | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/messages/textDocument_completion.cc b/src/messages/textDocument_completion.cc
index 5558c806..7d129a87 100644
--- a/src/messages/textDocument_completion.cc
+++ b/src/messages/textDocument_completion.cc
@@ -155,7 +155,8 @@ template <typename T> char *tofixedbase64(T input, char *out) {
 // when given 1000+ completion items.
 void FilterCandidates(Out_TextDocumentComplete *complete_response,
                       const std::string &complete_text, lsPosition begin_pos,
-                      lsPosition end_pos, bool has_open_paren) {
+                      lsPosition end_pos, bool has_open_paren,
+                      const std::string &buffer_line) {
   auto &items = complete_response->result.items;
 
   auto finalize = [&]() {
@@ -173,8 +174,15 @@ void FilterCandidates(Out_TextDocumentComplete *complete_response,
       // Order of textEdit and additionalTextEdits is unspecified.
       auto &edits = item.additionalTextEdits;
       if (edits.size() && edits[0].range.end == begin_pos) {
-        item.textEdit.range.start = edits[0].range.start;
+        lsPosition start = edits[0].range.start, end = edits[0].range.end;
+        item.textEdit.range.start = start;
         item.textEdit.newText = edits[0].newText + item.textEdit.newText;
+        if (start.line == begin_pos.line && item.filterText) {
+          item.filterText =
+              buffer_line.substr(start.character,
+                                 end.character - start.character) +
+              item.filterText.value();
+        }
         edits.erase(edits.begin());
       }
       // Compatibility
@@ -580,14 +588,14 @@ struct Handler_TextDocumentCompletion
       begin_pos.character = 0;
       end_pos.character = (int)buffer_line.size();
       FilterCandidates(&out, preprocess.pattern, begin_pos, end_pos,
-                       has_open_paren);
+                       has_open_paren, buffer_line);
       DecorateIncludePaths(preprocess.match, &out.result.items);
       pipeline::WriteStdout(kMethodType, out);
     } else {
       std::string path = params.textDocument.uri.GetPath();
       CompletionManager::OnComplete callback =
           [completion_text, path, begin_pos, end_pos, has_open_paren,
-           id = request->id](CodeCompleteConsumer *OptConsumer) {
+           id = request->id, buffer_line](CodeCompleteConsumer *OptConsumer) {
             if (!OptConsumer)
               return;
             auto *Consumer = static_cast<CompletionConsumer *>(OptConsumer);
@@ -596,7 +604,7 @@ struct Handler_TextDocumentCompletion
             out.result.items = Consumer->ls_items;
 
             FilterCandidates(&out, completion_text, begin_pos, end_pos,
-                             has_open_paren);
+                             has_open_paren, buffer_line);
             pipeline::WriteStdout(kMethodType, out);
             if (!Consumer->from_cache) {
               cache.WithLock([&]() {