add comment and check action type neovim goimports

Change-Id: Icfb3463546a889339f96720eb3e7603361e07fc7
GitHub-Last-Rev: 5aa0708d57ee9051561d2693edcb15f054b2f9e4
GitHub-Pull-Request: golang/tools#276
Reviewed-on: https://go-review.googlesource.com/c/tools/+/294529
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Trust: Rebecca Stambler <rstambler@golang.org>
Trust: Peter Weinberger <pjw@google.com>
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
gopls-CI: kokoro <noreply+kokoro@google.com>
TryBot-Result: Go Bot <gobot@golang.org>

gopls/doc/vim.md

@@ -171,17 +171,27 @@ lua <<EOF
     local params = vim.lsp.util.make_range_params()
     params.context = context
 
-    local method = "textDocument/codeAction"
-    local resp = vim.lsp.buf_request_sync(0, method, params, timeoutms)
-    if resp and resp[1] then
-      local result = resp[1].result
-      if result and result[1] then
-        local edit = result[1].edit
-        vim.lsp.util.apply_workspace_edit(edit)
-      end
-    end
+    -- See the implementation of the textDocument/codeAction callback
+    -- (lua/vim/lsp/handler.lua) for how to do this properly.
+    local result = vim.lsp.buf_request_sync(0, "textDocument/codeAction", params, timeout_ms)
+    if not result or next(result) == nil then return end
+    local actions = result[1].result
+    if not actions then return end
+    local action = actions[1]
 
-    vim.lsp.buf.formatting()
+    -- textDocument/codeAction can return either Command[] or CodeAction[]. If it
+    -- is a CodeAction, it can have either an edit, a command or both. Edits
+    -- should be executed first.
+    if action.edit or type(action.command) == "table" then
+      if action.edit then
+        vim.lsp.util.apply_workspace_edit(action.edit)
+      end
+      if type(action.command) == "table" then
+        vim.lsp.buf.execute_command(action.command)
+      end
+    else
+      vim.lsp.buf.execute_command(action)
+    end
   end
 EOF