lsp: add $/progress report (#13294)

Heavily inspired by https://github.com/nvim-lua/lsp-status.nvim.
listen to the LspProgressUpdate event to update your statusline.

runtime/lua/vim/lsp.lua

@@ -569,6 +569,8 @@ function lsp.start_client(config)
     -- TODO(remove-callbacks)
     callbacks = handlers;
     handlers = handlers;
+    -- for $/progress report
+    messages = { name = name, messages = {}, progress = {}, status = {} }
   }
 
   -- Store the uninitialized_clients for cleanup in case we exit before initialize finishes.

runtime/lua/vim/lsp/handlers.lua

@@ -24,6 +24,47 @@ M['workspace/executeCommand'] = function(err, _)
   end
 end
 
+-- @msg of type ProgressParams
+-- Basically a token of type number/string
+local function progress_callback(_, _, params, client_id)
+  local client = vim.lsp.get_client_by_id(client_id)
+  if not client then
+    err_message("LSP[", client_id, "] client has shut down after sending the message")
+  end
+  local val = params.value    -- unspecified yet
+  local token = params.token  -- string or number
+
+
+  if val.kind then
+    if val.kind == 'begin' then
+      client.messages.progress[token] = {
+        title = val.title,
+        message = val.message,
+        percentage = val.percentage,
+      }
+    elseif val.kind == 'report' then
+      client.messages.progress[token] = {
+        message = val.message,
+        percentage = val.percentage,
+      }
+    elseif val.kind == 'end' then
+      if client.messages.progress[token] == nil then
+        err_message(
+          'echom "[lsp-status] Received `end` message with no corresponding `begin` from "')
+      else
+        client.messages.progress[token].message = val.message
+        client.messages.progress[token].done = true
+      end
+    end
+  else
+    table.insert(client.messages, {content = val, show_once = true, shown = 0})
+  end
+
+  vim.api.nvim_command("doautocmd User LspProgressUpdate")
+end
+
+M['$/progress'] = progress_callback
+
 --@see https://microsoft.github.io/language-server-protocol/specifications/specification-current/#textDocument_codeAction
 M['textDocument/codeAction'] = function(_, _, actions)
   if actions == nil or vim.tbl_isempty(actions) then

runtime/lua/vim/lsp/protocol.lua

@@ -728,6 +728,9 @@ function protocol.make_client_capabilities()
       dynamicRegistration = false;
     };
     experimental = nil;
+    window = {
+      workDoneProgress = true;
+    }
   }
 end
 

runtime/lua/vim/lsp/util.lua

@@ -120,6 +120,63 @@ local function get_line_byte_from_position(bufnr, position)
   return col
 end
 
+--- Process and return progress reports from lsp server
+function M.get_progress_messages()
+
+  local new_messages = {}
+  local msg_remove = {}
+  local progress_remove = {}
+
+  for _, client in ipairs(vim.lsp.get_active_clients()) do
+      local messages = client.messages
+      local data = messages
+      for token, ctx in pairs(data.progress) do
+
+        local new_report = {
+          name = data.name,
+          title = ctx.title or "empty title",
+          message = ctx.message,
+          percentage = ctx.percentage,
+          progress = true,
+        }
+        table.insert(new_messages, new_report)
+
+        if ctx.done then
+          table.insert(progress_remove, {client = client, token = token})
+        end
+      end
+
+      for i, msg in ipairs(data.messages) do
+        if msg.show_once then
+          msg.shown = msg.shown + 1
+          if msg.shown > 1 then
+            table.insert(msg_remove, {client = client, idx = i})
+          end
+        end
+
+        table.insert(new_messages, {name = data.name, content = msg.content})
+      end
+
+      if next(data.status) ~= nil then
+        table.insert(new_messages, {
+          name = data.name,
+          content = data.status.content,
+          uri = data.status.uri,
+          status = true
+        })
+      end
+    for _, item in ipairs(msg_remove) do
+      table.remove(client.messages, item.idx)
+    end
+
+    for _, item in ipairs(progress_remove) do
+      client.messages.progress[item.token] = nil
+    end
+  end
+
+  return new_messages
+end
+
 --- Applies a list of text edits to a buffer.
 --@param text_edits (table) list of `TextEdit` objects
 --@param buf_nr (number) Buffer id