lsp: add 'textDocument/documentSymbol’ callback

Spec: https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_documentSymbol

runtime/doc/lsp.txt

@@ -48,6 +48,7 @@ go-to-definition, hover, etc.  Example config: >
   nnoremap <silent> <c-k> <cmd>lua vim.lsp.buf.signature_help()<CR>
   nnoremap <silent> 1gD   <cmd>lua vim.lsp.buf.type_definition()<CR>
   nnoremap <silent> gr    <cmd>lua vim.lsp.buf.references()<CR>
+  nnoremap <silent> g0    <cmd>lua vim.lsp.buf.document_symbol()<CR>
 
 Nvim provides the |vim.lsp.omnifunc| 'omnifunc' handler which allows
 |i_CTRL-X_CTRL-O| to consume LSP completion. Example config (note the use of
@@ -733,6 +734,9 @@ definition()                                        *vim.lsp.buf.definition()*
 document_highlight()                        *vim.lsp.buf.document_highlight()*
                 TODO: Documentation
 
+document_symbol()                              *vim.lsp.buf.document_symbol()*
+                TODO: Documentation
+
 formatting({options})                               *vim.lsp.buf.formatting()*
                 TODO: Documentation
 

runtime/lua/vim/lsp.lua

@@ -525,14 +525,15 @@ function lsp.start_client(config)
       callback = resolve_callback(method)
         or error("not found: request callback for client "..client.name)
     end
-    local _ = log.debug() and log.debug(log_prefix, "client.request", client_id, method, params, callback)
+    local _ = log.debug() and log.debug(log_prefix, "client.request", client_id, method, params, callback, bufnr)
     -- TODO keep these checks or just let it go anyway?
     if (not client.resolved_capabilities.hover and method == 'textDocument/hover')
       or (not client.resolved_capabilities.signature_help and method == 'textDocument/signatureHelp')
       or (not client.resolved_capabilities.goto_definition and method == 'textDocument/definition')
       or (not client.resolved_capabilities.implementation and method == 'textDocument/implementation')
+      or (not client.resolved_capabilities.document_symbol and method == 'textDocument/documentSymbol')
     then
-      callback(unsupported_method(method), method, nil, client_id)
+      callback(unsupported_method(method), method, nil, client_id, bufnr)
       return
     end
     return rpc.request(method, params, function(err, result)
@@ -874,7 +875,7 @@ end
 function lsp.buf_request_sync(bufnr, method, params, timeout_ms)
   local request_results = {}
   local result_count = 0
-  local function _callback(err, _method, result, client_id, bufnr)
+  local function _callback(err, _method, result, client_id)
     request_results[client_id] = { error = err, result = result }
     result_count = result_count + 1
   end
@@ -905,7 +906,7 @@ function lsp.buf_notify(bufnr, method, params)
     method   = { method, 's' };
   }
   local resp = false
-  for_each_buffer_client(bufnr, function(client, _client_id)
+  for_each_buffer_client(bufnr, function(client, _client_id, _resolved_bufnr)
     if client.rpc.notify(method, params) then resp = true end
   end)
   return resp

runtime/lua/vim/lsp/callbacks.lua

@@ -38,7 +38,13 @@ end
 
 M['textDocument/references'] = function(_, _, result)
   if not result then return end
-  util.set_qflist(result)
+  util.set_qflist(util.locations_to_items(result))
+end
+
+M['textDocument/documentSymbol'] = function(_, _, result, _, bufnr)
+  if not result or vim.tbl_isempty(result) then return end
+
+  util.set_qflist(util.symbols_to_items(result, bufnr))
   api.nvim_command("copen")
   api.nvim_command("wincmd p")
 end
@@ -97,7 +103,7 @@ local function location_callback(_, method, result)
   end
   util.jump_to_location(result[1])
   if #result > 1 then
-    util.set_qflist(result)
+    util.set_qflist(util.locations_to_items(result))
     api.nvim_command("copen")
     api.nvim_command("wincmd p")
   end

runtime/lua/vim/lsp/protocol.lua

@@ -663,19 +663,19 @@ function protocol.make_client_capabilities()
       documentHighlight = {
         dynamicRegistration = false
       };
-      -- documentSymbol = {
-      --   dynamicRegistration = false;
-      --   symbolKind = {
-      --     valueSet = (function()
-      --       local res = {}
-      --       for k in pairs(protocol.SymbolKind) do
-      --         if type(k) == 'string' then table.insert(res, k) end
-      --       end
-      --       return res
-      --     end)();
-      --   };
-      --   hierarchicalDocumentSymbolSupport = false;
-      -- };
+      documentSymbol = {
+        dynamicRegistration = false;
+        symbolKind = {
+          valueSet = (function()
+            local res = {}
+            for k in pairs(protocol.SymbolKind) do
+              if type(k) == 'number' then table.insert(res, k) end
+            end
+            return res
+          end)();
+        };
+        hierarchicalDocumentSymbolSupport = true;
+      };
     };
     workspace = nil;
     experimental = nil;

runtime/lua/vim/lsp/util.lua

@@ -834,23 +834,60 @@ function M.locations_to_items(locations)
   return items
 end
 
--- locations is Location[]
--- Only sets for the current window.
-function M.set_loclist(locations)
+function M.set_loclist(items)
   vim.fn.setloclist(0, {}, ' ', {
     title = 'Language Server';
-    items = M.locations_to_items(locations);
+    items = items;
   })
 end
 
--- locations is Location[]
-function M.set_qflist(locations)
+function M.set_qflist(items)
   vim.fn.setqflist({}, ' ', {
     title = 'Language Server';
-    items = M.locations_to_items(locations);
+    items = items;
   })
 end
 
+--- Convert symbols to quickfix list items
+---
+--@symbols DocumentSymbol[] or SymbolInformation[]
+function M.symbols_to_items(symbols, bufnr)
+  local function _symbols_to_items(_symbols, _items, _bufnr)
+    for _, symbol in ipairs(_symbols) do
+      if symbol.location then -- SymbolInformation type
+        local range = symbol.location.range
+        local kind = protocol.SymbolKind[symbol.kind]
+        table.insert(_items, {
+          filename = vim.uri_to_fname(symbol.location.uri),
+          lnum = range.start.line + 1,
+          col = range.start.character + 1,
+          kind = kind,
+          text = '['..kind..'] '..symbol.name,
+        })
+      elseif symbol.range then -- DocumentSymbole type
+        local kind = protocol.SymbolKind[symbol.kind]
+        table.insert(_items, {
+          -- bufnr = _bufnr,
+          filename = vim.api.nvim_buf_get_name(_bufnr),
+          lnum = symbol.range.start.line + 1,
+          col = symbol.range.start.character + 1,
+          kind = kind,
+          text = '['..kind..'] '..symbol.name
+        })
+        if symbol.children then
+          for _, child in ipairs(symbol) do
+            for _, v in ipairs(_symbols_to_items(child, _items, _bufnr)) do
+              vim.list_extend(_items, v)
+            end
+          end
+        end
+      end
+    end
+    return _items
+  end
+  return _symbols_to_items(symbols, {}, bufnr)
+end
+
 -- Remove empty lines from the beginning and end.
 function M.trim_empty_lines(lines)
   local start = 1
@@ -903,11 +940,15 @@ function M.make_position_params()
   local line = api.nvim_buf_get_lines(0, row, row+1, true)[1]
   col = str_utfindex(line, col)
   return {
-    textDocument = { uri = vim.uri_from_bufnr(0) };
+    textDocument = M.make_text_document_params();
     position = { line = row; character = col; }
   }
 end
 
+function M.make_text_document_params()
+  return { uri = vim.uri_from_bufnr(0) }
+end
+
 -- @param buf buffer handle or 0 for current.
 -- @param row 0-indexed line
 -- @param col 0-indexed byte offset in line

test/functional/plugin/lsp_spec.lua

@@ -241,7 +241,7 @@ describe('LSP', function()
 
     it('should succeed with manual shutdown', function()
       local expected_callbacks = {
-        {NIL, "shutdown", {}, 1};
+        {NIL, "shutdown", {}, 1, NIL};
         {NIL, "test", {}, 1};
       }
       test_rpc_server {