LSP: Feature/add workspace folders (#12638)

* First implementation of workspace folders
* Add completion for current directory
* Add tracking of workspace folders
* Add workspace folder listing
* Add checks on adding/removing workspaces
* Add appropriate initialization options
* Add documentation
* Make workspaceFolders available wherever client is

1 files changed, 55 insertions, 0 deletions

diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index fa62905c0a..a70581478b 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -238,6 +238,61 @@ function M.outgoing_calls()
   end)
 end
 
+--- List workspace folders.
+function M.list_workspace_folders()
+  local workspace_folders = {}
+  for _, client in ipairs(vim.lsp.buf_get_clients()) do
+    for _, folder in ipairs(client.workspaceFolders) do
+      table.insert(workspace_folders, folder.name)
+    end
+  end
+  return workspace_folders
+end
+
+--- Add a workspace folder.
+function M.add_workspace_folder(workspace_folder)
+  workspace_folder = workspace_folder or npcall(vfn.input, "Workspace Folder: ", vfn.expand('%:p:h'))
+  vim.api.nvim_command("redraw")
+  if not (workspace_folder and #workspace_folder > 0) then return end
+  if vim.fn.isdirectory(workspace_folder) == 0 then
+    print(workspace_folder, " is not a valid directory")
+    return
+  end
+  local params = util.make_workspace_params({{uri = vim.uri_from_fname(workspace_folder); name = workspace_folder}}, {{}})
+  for _, client in ipairs(vim.lsp.buf_get_clients()) do
+    local found = false
+    for _, folder in ipairs(client.workspaceFolders) do
+      if folder.name == workspace_folder then
+        found = true
+        print(workspace_folder, "is already part of this workspace")
+        break
+      end
+    end
+    if not found then
+      vim.lsp.buf_notify(0, 'workspace/didChangeWorkspaceFolders', params)
+      table.insert(client.workspaceFolders, params.event.added[1])
+    end
+  end
+end
+
+--- Remove a workspace folder.
+function M.remove_workspace_folder(workspace_folder)
+  workspace_folder = workspace_folder or npcall(vfn.input, "Workspace Folder: ", vfn.expand('%:p:h'))
+  vim.api.nvim_command("redraw")
+  if not (workspace_folder and #workspace_folder > 0) then return end
+  local params = util.make_workspace_params({{}}, {{uri = vim.uri_from_fname(workspace_folder); name = workspace_folder}})
+  for _, client in ipairs(vim.lsp.buf_get_clients()) do
+    for idx, folder in ipairs(client.workspaceFolders) do
+      if folder.name == workspace_folder then
+        vim.lsp.buf_notify(0, 'workspace/didChangeWorkspaceFolders', params)
+        client.workspaceFolders[idx] = nil
+        return
+      end
+    end
+  end
+  print(workspace_folder,  "is not currently part of the workspace")
+end
+
 --- Lists all symbols in the current workspace in the quickfix window.
 ---
 --- The list is filtered against {query}; if the argument is omitted from the