nvim: lsp: Add support for reloading Cargo workspace

While at it, refactor the custom setup and clean up for clients in
a single function.

nvim/.config/nvim/after/ftplugin/rust.lua

@@ -11,6 +11,7 @@ vim.keymap.set('n', 'cbc', ":Dispatch! cargo clean<CR>"     , { noremap=true, bu
 vim.keymap.set('n', 'cbd', ":Dispatch! cargo doc<CR>"       , { noremap=true, buffer=0 })
 vim.keymap.set('n', 'cdD', ":Dispatch! cargo doc --open<CR>", { noremap=true, buffer=0 })
 vim.keymap.set('n', 'cbu', ":Dispatch! cargo update<CR>"    , { noremap=true, buffer=0 })
+vim.keymap.set('n', ',r' , ":CargoReload<CR>"               , { noremap=true, buffer=0 })
 
 vim.api.nvim_create_autocmd({ "BufReadPre", "BufWinEnter" }, {
   pattern  = { "*/git/checkouts/*", "*/toolchains/*", "*cargo/registry/*" },

nvim/.config/nvim/lua/lsp.lua

@@ -80,12 +80,18 @@ local lsp_key_mappings = {
   { "codeLensProvider", 'n', '<LocalLeader>L', '<cmd>lua vim.lsp.codelens.clear()<CR>' },
 }
 
-local tsserver_setup = function(client)
-  if client.name == 'tsserver' then
-    -- Disable tsserver formatting, we want formatting via prettier
-    client.server_capabilities.documentFormattingProvider      = false
-    client.server_capabilities.documentRangeFormattingProvider = false
-  end
+local cargo_reload_workspace = function()
+  vim.lsp.buf_request(0, 'rust-analyzer/reloadWorkspace', nil, function(err)
+    if err then
+      vim.schedule(function()
+        vim.notify('Cargo reload workspace gave error: ' .. tostring(err), vim.log.levels.ERROR)
+      end)
+    else
+      vim.schedule(function()
+        vim.notify 'Cargo workspace reloaded'
+      end)
+    end
+  end)
 end
 
 local get_active_client_by_name = function(bufnr, servername)
@@ -124,16 +130,30 @@ local switch_source_header = function()
   end
 end
 
-local clangd_setup = function(client)
+local client_custom_setup = function(client)
   if client.name == 'clangd' then
     vim.api.nvim_create_user_command("ClangdSwitchSourceHeader", switch_source_header, {desc = 'Switch between source/header'})
   end
+
+  if client.name == 'rust-analyzer' then
+    vim.api.nvim_create_user_command("CargoReload", cargo_reload_workspace, {desc = 'Reload current cargo workspace'})
+  end
+
+  if client.name == 'tsserver' then
+    -- Disable tsserver formatting, we want formatting via prettier
+    client.server_capabilities.documentFormattingProvider      = false
+    client.server_capabilities.documentRangeFormattingProvider = false
+  end
 end
 
-local clangd_cleanup = function(client)
+local client_custom_cleanup = function(client)
   if client.name == 'clangd' then
     vim.api.nvim_del_user_command("ClangdSwitchSourceHeader")
   end
+
+  if client.name == 'rust-analyzer' then
+    vim.api.nvim_del_user_command("CargoReload")
+  end
 end
 
 local on_attach = function(client, bufnr)
@@ -146,11 +166,7 @@ local on_attach = function(client, bufnr)
 
   local opts = { noremap=true, silent=true }
 
-  -- This needs to be here, so we disable formatting with tsserver before
-  -- actually checking it below.
-  tsserver_setup(client)
-
-  clangd_setup(client)
+  client_custom_setup(client)
 
   for _, mappings in pairs(lsp_key_mappings) do
     local capability, mode, lhs, rhs = unpack(mappings)
@@ -219,6 +235,6 @@ vim.api.nvim_create_autocmd("LspDetach", {
       end
     end
 
-    clangd_cleanup(client)
+    client_custom_cleanup(client)
   end,
 })