fix(util): Util.merge now skips nil args

Author: folke

lua/lazy/core/util.lua

@@ -396,22 +396,19 @@ end
 ---@param ... T
 ---@return T
 function M.merge(...)
-  local values = { ... }
-  local ret = values[1]
-
+  local ret = select(1, ...)
   if ret == vim.NIL then
     ret = nil
   end
-
-  for i = 2, #values, 1 do
-    local value = values[i]
+  for i = 2, select("#", ...) do
+    local value = select(i, ...)
     if can_merge(ret) and can_merge(value) then
       for k, v in pairs(value) do
         ret[k] = M.merge(ret[k], v)
       end
     elseif value == vim.NIL then
       ret = nil
-    else
+    elseif value ~= nil then
       ret = value
     end
   end

tests/core/util_spec.lua

@@ -101,6 +101,22 @@ describe("util", function()
         input = { { a = 1 }, { b = 2 } },
         output = { a = 1, b = 2 },
       },
+      {
+        input = { nil, { a = 1 }, { b = 2 } },
+        output = { a = 1, b = 2 },
+      },
+      {
+        input = { { a = 1 }, { b = 2 }, nil },
+        output = { a = 1, b = 2 },
+      },
+      {
+        input = { { a = 1 }, nil, { b = 2 } },
+        output = { a = 1, b = 2 },
+      },
+      {
+        input = { nil, { a = 1 }, nil, { b = 2 }, nil },
+        output = { a = 1, b = 2 },
+      },
       {
         input = { { a = 1 }, { a = 2 } },
         output = { a = 2 },
@@ -120,7 +136,11 @@ describe("util", function()
     }
 
     for _, test in ipairs(tests) do
-      assert.same(test.output, Util.merge(unpack(test.input)))
+      local n = 0
+      for i in pairs(test.input) do
+        n = math.max(n, i)
+      end
+      assert.same(test.output, Util.merge(unpack(test.input, 1, n)))
     end
   end)
 end)