test: share implementation of testdir/load.vim

Also, don't compute load factor unless load_adjust() was called, it
slows down the test suite.

ref #9292

src/nvim/testdir/load.vim

@@ -1,3 +1,5 @@
+" Also used by: test/functional/helpers.lua
+
 function! s:load_factor() abort
   let timeout = 200
   let times = []
@@ -23,8 +25,8 @@ function! s:load_factor() abort
 endfunction
 
 " Compute load factor only once.
-let s:load_factor = s:load_factor()
+let g:test_load_factor = s:load_factor()
 
 function! LoadAdjust(num) abort
-  return float2nr(ceil(a:num * s:load_factor))
+  return float2nr(ceil(a:num * g:test_load_factor))
 endfunction

src/nvim/testdir/test_timers.vim

@@ -15,17 +15,13 @@ func MyHandlerWithLists(lists, timer)
   let x = string(a:lists)
 endfunc
 
-func s:assert_inrange(lower, upper, actual)
-  return assert_inrange(a:lower, LoadAdjust(a:upper), a:actual)
-endfunc
-
 func Test_oneshot()
   let g:val = 0
   let timer = timer_start(50, 'MyHandler')
   let slept = WaitFor('g:val == 1')
   call assert_equal(1, g:val)
   if has('reltime')
-    call s:assert_inrange(40, 120, slept)
+    call assert_inrange(40, LoadAdjust(120), slept)
   else
     call assert_inrange(20, 120, slept)
   endif
@@ -37,7 +33,7 @@ func Test_repeat_three()
   let slept = WaitFor('g:val == 3')
   call assert_equal(3, g:val)
   if has('reltime')
-    call s:assert_inrange(120, 250, slept)
+    call assert_inrange(120, LoadAdjust(250), slept)
   else
     call assert_inrange(80, 200, slept)
   endif
@@ -52,7 +48,7 @@ func Test_repeat_many()
   endif
   sleep 200m
   call timer_stop(timer)
-  call s:assert_inrange((has('mac') ? 1 : 2), 4, g:val)
+  call assert_inrange((has('mac') ? 1 : 2), LoadAdjust(4), g:val)
 endfunc
 
 func Test_with_partial_callback()
@@ -66,7 +62,7 @@ func Test_with_partial_callback()
   let slept = WaitFor('g:val == 1')
   call assert_equal(1, g:val)
   if has('reltime')
-    call s:assert_inrange(40, 130, slept)
+    call assert_inrange(40, LoadAdjust(130), slept)
   else
     call assert_inrange(20, 100, slept)
   endif
@@ -129,7 +125,7 @@ func Test_paused()
   let slept = WaitFor('g:val == 1')
   call assert_equal(1, g:val)
   if has('reltime')
-    call s:assert_inrange(0, 140, slept)
+    call assert_inrange(0, LoadAdjust(140), slept)
   else
     call assert_inrange(0, 10, slept)
   endif

test/functional/helpers.lua

@@ -739,41 +739,14 @@ local function alter_slashes(obj)
   end
 end
 
-local function compute_load_factor()
-  local timeout = 200
-  local times = {}
-
-  clear()
-
-  for _ = 1, 5 do
-    source([[
-      let g:val = 0
-      call timer_start(200, {-> nvim_set_var('val', 1)})
-      let start = reltime()
-      while 1
-        sleep 10m
-        if g:val == 1
-          let g:waited_in_ms = float2nr(reltimefloat(reltime(start)) * 1000)
-          break
-        endif
-      endwhile
-    ]])
-    table.insert(times, nvim_eval('g:waited_in_ms'))
-  end
-
-  session:close()
-  session = nil
-
-  local longest = math.max(unpack(times))
-  local factor = (longest + 50.0) / timeout
-
-  return factor
-end
-
--- Compute load factor only once.
-local load_factor = compute_load_factor()
 
+local load_factor = nil
 local function load_adjust(num)
+  if load_factor == nil then  -- Compute load factor only once.
+    clear()
+    request('nvim_command', 'source src/nvim/testdir/load.vim')
+    load_factor = request('nvim_eval', 'g:test_load_factor')
+  end
   return math.ceil(num * load_factor)
 end