feat(clue): ensure triggers in 'mini.starter', but prefer its updaters

Details:
- The fact that 'mini.clue' doesn't work with 'mini.starter' is mostly
  an implementation detail (they both use buffer-local mappings). This
  can be overcome by a reasonably straightforward autocommand that
  ensures 'mini.clue' triggers and restores conflicting 'mini.starter'
  mappings, but this is not quite beginner friendly.
  It is more important in MiniMax, as there were couple of issues with
  'mini.clue' not working in 'mini.starter' in the first two weeks after
  Minimax release.

Resolve #1739

Author: echasnovski

CHANGELOG.md

@@ -81,6 +81,8 @@ There are following change types:
 
 - Add `gen_clues.square_brackets` to generate clues for `[` and `]` keys. By @TheLeoP, PR #1937.
 
+- Ensure triggers for 'mini.starter' buffers, but not override its query updaters (like for "g" and "z" triggers).
+
 ## mini.diff
 
 ### Expand

lua/mini/clue.lua

@@ -1184,7 +1184,7 @@ H.keys = {
 -- Special filetypes for which to enable triggers. These are common interactive
 -- not listed filetypes. NOTE: no 'minifiles' as `'` trigger conflicts with its
 -- local `'`. Plus it pollutes `g?` content.
-H.ft_to_enable = { help = true, git = true }
+H.ft_to_enable = { help = true, git = true, ministarter = true }
 
 -- Timers
 H.timers = {
@@ -1338,7 +1338,11 @@ H.map_trigger = function(buf_id, trigger)
 
   -- Compute mapping RHS
   trigger.keys = H.replace_termcodes(trigger.keys)
-  local keys_trans = H.keytrans(trigger.keys)
+  local lhs = H.keytrans(trigger.keys)
+
+  local is_ministarter_map = vim.bo[buf_id].filetype == 'ministarter'
+    and vim.api.nvim_buf_call(buf_id, function() return vim.fn.maparg(lhs, trigger.mode) ~= '' end)
+  if is_ministarter_map then return end
 
   local rhs = function()
     -- Don't act if for some reason entered the same trigger during state exec
@@ -1362,11 +1366,11 @@ H.map_trigger = function(buf_id, trigger)
 
   -- Use buffer-local mappings and `nowait` to make it a primary source of
   -- keymap execution
-  local desc = string.format('Query keys after "%s"', keys_trans)
+  local desc = string.format('Query keys after "%s"', lhs)
   local opts = { buffer = buf_id, nowait = true, desc = desc }
 
   -- Create mapping. Use translated variant to make it work with <F*> keys.
-  vim.keymap.set(trigger.mode, keys_trans, rhs, opts)
+  vim.keymap.set(trigger.mode, lhs, rhs, opts)
 end
 
 H.unmap_trigger = function(buf_id, trigger)

tests/test_clue.lua

@@ -360,6 +360,19 @@ T['setup()']['ensures valid triggers on selected special buffers'] = function()
   validate_trigger('git', buf_id_git)
 end
 
+T['setup()']["works with 'mini.starter'"] = function()
+  child.lua('require("mini.starter").open()')
+  local triggers = {
+    { mode = 'n', keys = '<Space>' },
+    { mode = 'n', keys = 'g' },
+  }
+  load_module({ triggers = triggers, window = { delay = 0 } })
+
+  -- Should not override query updaters (common for "g", "s", "z" triggers)
+  validate_trigger_keymap('n', '<Space>', 0)
+  validate_no_trigger_keymap('n', 'g', 0)
+end
+
 T['setup()']['respects `vim.b.miniclue_disable`'] = function()
   local init_buf_id = child.api.nvim_get_current_buf()
   local other_buf_id = child.api.nvim_create_buf(true, false)