fix(tests): use uv.spawn instead of io.popen for unittest helpers

The old implementation of repeated_read_cmd would attempt to run the
command multiple times to handle racyness of async output. Code
like this should not be written. Instead, use the libuv event
loop to read until the process has exited and the pipe has been closed.

This causes some previous discarded errors to be propagated. Fix these
as well.

test/testutil.lua

@@ -5,17 +5,6 @@ local Paths = require('test.cmakeconfig.paths')
 
 luaassert:set_parameter('TableFormatLevel', 100)
 
-local quote_me = '[^.%w%+%-%@%_%/]' -- complement (needn't quote)
-
---- @param str string
---- @return string
-local function shell_quote(str)
-  if string.find(str, quote_me) or str == '' then
-    return '"' .. str:gsub('[$%%"\\]', '\\%0') .. '"'
-  end
-  return str
-end
-
 --- Functions executing in the context of the test runner (not the current nvim test session).
 --- @class test.testutil
 local M = {
@@ -66,19 +55,15 @@ function M.argss_to_cmd(...)
   for i = 1, select('#', ...) do
     local arg = select(i, ...)
     if type(arg) == 'string' then
-      cmd[#cmd + 1] = shell_quote(arg)
+      cmd[#cmd + 1] = arg
     else
       --- @cast arg string[]
       for _, subarg in ipairs(arg) do
-        cmd[#cmd + 1] = shell_quote(subarg)
+        cmd[#cmd + 1] = subarg
       end
     end
   end
-  return table.concat(cmd, ' ')
-end
-
-function M.popen_r(...)
-  return io.popen(M.argss_to_cmd(...), 'r')
+  return cmd
 end
 
 --- Calls fn() until it succeeds, up to `max` times or until `max_ms`
@@ -356,7 +341,7 @@ function M.check_logs()
           local status, f
           local out = io.stdout
           if os.getenv('SYMBOLIZER') then
-            status, f = pcall(M.popen_r, os.getenv('SYMBOLIZER'), '-l', file)
+            status, f = pcall(M.repeated_read_cmd, os.getenv('SYMBOLIZER'), '-l', file)
           end
           out:write(start_msg .. '\n')
           if status then
@@ -539,16 +524,37 @@ end
 
 --- @return string?
 function M.repeated_read_cmd(...)
-  for _ = 1, 10 do
-    local stream = M.popen_r(...)
-    local ret = stream:read('*a')
-    stream:close()
-    if ret then
-      return ret
+  local cmd = M.argss_to_cmd(...)
+  local data = {}
+  local got_code = nil
+  local stdout = assert(vim.uv.new_pipe(false))
+  local handle = assert(
+    vim.uv.spawn(
+      cmd[1],
+      { args = vim.list_slice(cmd, 2), stdio = { nil, stdout, 2 }, hide = true },
+      function(code, _signal)
+        got_code = code
       end
+    )
+  )
+  stdout:read_start(function(err, chunk)
+    if err or chunk == nil then
+      stdout:read_stop()
+      stdout:close()
+    else
+      table.insert(data, chunk)
     end
-  print('ERROR: Failed to execute ' .. M.argss_to_cmd(...) .. ': nil return after 10 attempts')
-  return nil
+  end)
+
+  while not stdout:is_closing() or got_code == nil do
+    vim.uv.run('once')
+  end
+
+  if got_code ~= 0 then
+    error('command ' .. vim.inspect(cmd) .. 'unexpectedly exited with status ' .. got_code)
+  end
+  handle:close()
+  return table.concat(data)
 end
 
 --- @generic T

test/unit/api/private_helpers_spec.lua

@@ -18,7 +18,7 @@ local type_key = api_t.type_key
 local obj2lua = api_t.obj2lua
 local func_type = api_t.func_type
 
-local api = cimport('./src/nvim/api/private/t.h', './src/nvim/api/private/converter.h')
+local api = cimport('./src/nvim/api/private/helpers.h', './src/nvim/api/private/converter.h')
 
 describe('vim_to_object', function()
   local vim_to_object = function(l)

test/unit/api/testutil.lua

@@ -13,8 +13,11 @@ local int_type = t_eval.int_type
 local flt_type = t_eval.flt_type
 local type_key = t_eval.type_key
 
-local api =
-  cimport('./src/nvim/api/private/defs.h', './src/nvim/api/private/t.h', './src/nvim/memory.h')
+local api = cimport(
+  './src/nvim/api/private/defs.h',
+  './src/nvim/api/private/helpers.h',
+  './src/nvim/memory.h'
+)
 
 local obj2lua
 

test/unit/vterm_spec.lua

@@ -94,7 +94,7 @@ local vterm = t.cimport(
   './src/nvim/vterm/screen.h',
   './src/nvim/vterm/state.h',
   './src/nvim/vterm/vterm.h',
-  './src/nvim/vterm/vterm_internal.h',
+  './src/nvim/vterm/vterm_internal_defs.h',
   './test/unit/fixtures/vterm_test.h'
 )