path: root/test/functional/harness/harness_spec.lua

-- Black-box tests for the local Lua harness itself. These spawn a separate
-- Nvim process instead of driving an embedded instance via testnvim.
local t = require('test.testutil')
local describe, it, pending, finally = t.describe, t.it, t.pending, t.finally
local uv = vim.uv

local eq = t.eq
local matches = t.matches
local not_matches = t.not_matches

local root = t.paths.test_source_path
local build_dir = t.paths.test_build_dir
local nvim_prog = build_dir .. '/bin/nvim'
local runner = root .. '/test/runner.lua'

---@param path string
local function mkdir(path)
  assert(t.mkdir(path), ('failed to create directory: %s'):format(path))
end

-- Prepended to each *_spec.lua fixture so it can use the test framework.
local spec_preamble = "local h = require('test.harness'); local eq = require('test.assert').eq; "
  .. 'local describe, it, before_each, after_each, setup, teardown, pending, finally = '
  .. 'h.describe, h.it, h.before_each, h.after_each, h.setup, h.teardown, h.pending, h.finally; '

---@param suite_files table<string, string>
---@return string
local function write_suite(suite_files)
  local dir = t.tmpname(false)
  mkdir(dir)

  for name, contents in pairs(suite_files) do
    if name:match('_spec%.lua$') then
      contents = spec_preamble .. contents
    end
    t.write_file(dir .. '/' .. name, contents)
  end

  return dir
end

---@param overrides table<string, string?>
---@return string[]
local function make_env(overrides)
  local env = uv.os_environ()
  for k, v in pairs(overrides) do
    env[k] = v
  end

  local items = {}
  for k, v in pairs(env) do
    if v ~= nil then
      items[#items + 1] = k .. '=' .. v
    end
  end

  return items
end

---@param suite_dir string
---@param extra_args? string[]
---@return integer, string
local function run_harness(suite_dir, extra_args)
  local env_root = t.tmpname(false)
  mkdir(env_root)
  mkdir(env_root .. '/config')
  mkdir(env_root .. '/share')
  mkdir(env_root .. '/state')
  mkdir(env_root .. '/tmp')

  local stdout = assert(uv.new_pipe(false))
  local stderr = assert(uv.new_pipe(false))
  local out = {}
  local err = {}
  local exit_code --- @type integer?

  local args = {
    '-l',
    runner,
    '-v',
    '--lpath=' .. build_dir .. '/?.lua',
    '--lpath=' .. root .. '/src/?.lua',
    '--lpath=' .. root .. '/runtime/lua/?.lua',
    '--lpath=' .. suite_dir .. '/?.lua',
    '--lpath=?.lua',
  }
  for _, arg in ipairs(extra_args or {}) do
    args[#args + 1] = arg
  end
  args[#args + 1] = suite_dir

  local handle = assert(uv<