From e65d0e53b1234f9173831a8a34c4e64d5542b0cb Mon Sep 17 00:00:00 2001
From: smolck <46855713+smolck@users.noreply.github.com>
Date: Wed, 3 Feb 2021 18:13:04 -0600
Subject: [PATCH] vim.fn: throw error when trying to use API function

---
 src/nvim/lua/vim.lua | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/nvim/lua/vim.lua b/src/nvim/lua/vim.lua
index dbf4f6014c..e154404836 100644
--- a/src/nvim/lua/vim.lua
+++ b/src/nvim/lua/vim.lua
@@ -253,9 +253,17 @@ end
 -- vim.fn.{func}(...)
 vim.fn = setmetatable({}, {
   __index = function(t, key)
-    local function _fn(...)
-      return vim.call(key, ...)
+    local _fn
+    if vim.api[key] ~= nil then
+      _fn = function(...)
+        error(string.format("Tried to call API function with vim.fn: use vim.api.%s() instead", key))
+      end
+    else
+      _fn = function(...)
+        return vim.call(key, ...)
+      end
     end
+
     t[key] = _fn
     return _fn
   end