fix(pick)!: increase default config.delay.async from 10 to 100

Details:
- Having 10ms as a default ensures the smoothest async experience, since
  it results in essentially 100 FPS responsiveness.

  However, this is a bit too much for "force redraw during `getchar()`"
  and can result into constant 1-2% CPU load just when picker does
  nothing. This is the biggest load, but it adds up and can have visible
  effect if the picker is left open in the background after switching to
  a different process.

- This also makes it "less smooth" of a feeling to type when the picker
  is busy. However, should still be good enough while consuming slightly
  less resources (due to less frequent checks).

  If it causes visible issues, the two more complex solutions here are:

    - Add new `config.delay.poke` to separate `async` for redraw and
      `check` for throttled poking.

    - Make upstream Neovim PR to allow `getchar()` / `getcharstr()` to
      not block redraw (at least behind the new option).

Related to #2306

Author: echasnovski

CHANGELOG.md

@@ -66,6 +66,10 @@ There are following change types:
 
 - Allow `source.preview` to directly set another buffer into picker's main window. The recommended way is still to adjust the provided `buf_id` buffer, but there is now a workaround if this is not reasonably possible.
 
+### Refine
+
+- Increase default value `config.delay.async` from 10 to 100. This should reduce CPU load (as there will be less forced `:redraw` calls for every picker) while still being small enough to feel smooth typing when the picker is busy.
+
 ## mini.surround
 
 ### Expand

doc/mini-pick.txt

@@ -207,6 +207,7 @@ milliseconds of idle time.
   control over their side effects. As a result, regular mappings don't work
   here and picker's window needs to be current as long as it is shown.
   Changing window focus leads to automatic picker stop (after small delay).
+  Not picker related redraws are forced every `config.delay.async` milliseconds.
 - Any picker is non-blocking but waits to return the chosen item. Example:
   `file = MiniPick.builtin.files()` allows other actions to be executed when
   picker is shown while still assigning `file` with value of the chosen item.
@@ -707,7 +708,7 @@ Defaults ~
     -- Delays (in ms; should be at least 1)
     delay = {
       -- Delay between forcing asynchronous behavior
-      async = 10,
+      async = 100,
 
       -- Delay between computation start and visual feedback about it
       busy = 50,

lua/mini/pick.lua

@@ -203,6 +203,7 @@
 ---   control over their side effects. As a result, regular mappings don't work
 ---   here and picker's window needs to be current as long as it is shown.
 ---   Changing window focus leads to automatic picker stop (after small delay).
+---   Not picker related redraws are forced every `config.delay.async` milliseconds.
 --- - Any picker is non-blocking but waits to return the chosen item. Example:
 ---   `file = MiniPick.builtin.files()` allows other actions to be executed when
 ---   picker is shown while still assigning `file` with value of the chosen item.
@@ -795,7 +796,7 @@ MiniPick.config = {
   -- Delays (in ms; should be at least 1)
   delay = {
     -- Delay between forcing asynchronous behavior
-    async = 10,
+    async = 100,
 
     -- Delay between computation start and visual feedback about it
     busy = 50,

readmes/mini-pick.md

@@ -237,7 +237,7 @@ Here are code snippets for some common installation methods (use only one):
   -- Delays (in ms; should be at least 1)
   delay = {
     -- Delay between forcing asynchronous behavior
-    async = 10,
+    async = 100,
 
     -- Delay between computation start and visual feedback about it
     busy = 50,

tests/test_pick.lua

@@ -272,7 +272,7 @@ T['setup()']['creates `config` field'] = function()
   -- Check default values
   local expect_config = function(field, value) eq(child.lua_get('MiniPick.config.' .. field), value) end
 
-  expect_config('delay.async', 10)
+  expect_config('delay.async', 100)
   expect_config('delay.busy', 50)
 
   expect_config('mappings.caret_left', '<Left>')
@@ -606,10 +606,12 @@ T['start()']['respects `source.items`'] = function()
   stop()
 
   -- Problematic items
-  child.lua_notify('_G.res = MiniPick.start({ source = { items = { vim.uv.new_timer() } } })')
-  eq(child.lua_get('vim.tbl_map(type, MiniPick.get_picker_items())'), { 'userdata' })
-  type_keys('<CR>')
-  eq(child.lua_get('type(_G.res)'), 'userdata')
+  if child.fn.has('nvim-0.10') == 1 then
+    child.lua_notify('_G.res = MiniPick.start({ source = { items = { vim.uv.new_timer() } } })')
+    eq(child.lua_get('vim.tbl_map(type, MiniPick.get_picker_items())'), { 'userdata' })
+    type_keys('<CR>')
+    eq(child.lua_get('type(_G.res)'), 'userdata')
+  end
 end
 
 T['start()']['correctly computes stritems'] = function()
@@ -1636,6 +1638,7 @@ end
 T['default_preview()']['can be used in outside preview window'] = function()
   -- This is not a module's capabilitiy per se, but something it should allow
   local item = { path = real_file('b.txt'), lnum = 5, text = 'b.txt' }
+  child.lua('MiniPick.config.delay.async = 1')
   start_with_items({ item })
 
   local buf_id = child.api.nvim_create_buf(false, true)