feat(util): Util.merge now support advanced merging strategies. Docs coming soon

lua/lazy/core/plugin.lua

@@ -270,20 +270,10 @@ function Spec:merge(old, new)
 
   for _, prop in ipairs(list_merge) do
     if new[prop] and old[prop] then
-      ---@type any[]
-      local props = {}
-      ---@diagnostic disable-next-line: no-unknown
-      for _, value in ipairs(old[prop]) do
-        props[#props + 1] = value
+      if new[prop].__merge == nil then
+        new[prop].__merge = true
       end
-      ---@diagnostic disable-next-line: no-unknown
-      for _, value in ipairs(new[prop]) do
-        if not vim.tbl_contains(props, value) then
-          props[#props + 1] = value
-        end
-      end
-      ---@diagnostic disable-next-line: no-unknown
-      new[prop] = props
+      new[prop] = Util.merge(old[prop], new[prop])
     end
   end
   new._.super = old

lua/lazy/core/util.lua

@@ -286,10 +286,27 @@ function M.debug(msg, level, opts)
   end
 end
 
+local MERGE = "__merge"
+
 local function can_merge(v)
   return type(v) == "table" and (vim.tbl_isempty(v) or not M.is_list(v))
 end
 
+local function can_extend(v)
+  return type(v) == "table" and (vim.tbl_isempty(v) or M.is_list(v))
+end
+
+---@param v any|{__merge:boolean}
+---@param merge? boolean
+---@return boolean?
+local function check_merge(v, merge)
+  if type(v) == "table" and v[MERGE] ~= nil then
+    merge = v[MERGE]
+    v[MERGE] = nil
+  end
+  return merge
+end
+
 --- Merges the values similar to vim.tbl_deep_extend with the **force** behavior,
 --- but the values can be any type, in which case they override the values on the left.
 --- Values will me merged in-place in the first left-most table. If you want the result to be in
@@ -301,12 +318,24 @@ end
 function M.merge(...)
   local values = { ... }
   local ret = values[1]
+
+  if ret == vim.NIL then
+    ret = nil
+  end
+
+  local merge = check_merge(ret)
+
   for i = 2, #values, 1 do
     local value = values[i]
-    if can_merge(ret) and can_merge(value) then
+    merge = check_merge(value, merge)
+    if can_merge(ret) and can_merge(value) and merge ~= false then
       for k, v in pairs(value) do
         ret[k] = M.merge(ret[k], v)
       end
+    elseif can_extend(ret) and can_extend(value) and merge then
+      for _, v in ipairs(value) do
+        ret[#ret + 1] = v
+      end
     elseif value == vim.NIL then
       ret = nil
     else