neovim/test/functional/api/proc_spec.lua

local helpers = require('test.functional.helpers')(after_each)

local clear = helpers.clear
local eq = helpers.eq
local funcs = helpers.funcs
local iswin = helpers.iswin
local nvim_argv = helpers.nvim_argv
local ok = helpers.ok
local request = helpers.request
local retry = helpers.retry
local NIL = helpers.NIL

describe('api', function()
  before_each(clear)

  describe('nvim_get_proc_children', function()
    it('returns child process ids', function()
      local this_pid = funcs.getpid()

      local job1 = funcs.jobstart(nvim_argv)
      retry(nil, nil, function()
        eq(1, #request('nvim_get_proc_children', this_pid))
      end)

      local job2 = funcs.jobstart(nvim_argv)
      retry(nil, nil, function()
        eq(2, #request('nvim_get_proc_children', this_pid))
      end)

      funcs.jobstop(job1)
      retry(nil, nil, function()
        eq(1, #request('nvim_get_proc_children', this_pid))
      end)

      funcs.jobstop(job2)
      retry(nil, nil, function()
        eq(0, #request('nvim_get_proc_children', this_pid))
      end)
    end)

    it('validates input', function()
      local status, rv = pcall(request, "nvim_get_proc_children", -1)
      eq(false, status)
      eq("Invalid pid: -1", string.match(rv, "Invalid.*"))

      status, rv = pcall(request, "nvim_get_proc_children", 0)
      eq(false, status)
      eq("Invalid pid: 0", string.match(rv, "Invalid.*"))

      -- Assume PID 99999 does not exist.
      status, rv = pcall(request, "nvim_get_proc_children", 99999)
      eq(true, status)
      eq({}, rv)
    end)
  end)

  describe('nvim_get_proc', function()
    it('returns process info', function()
      local pid = funcs.getpid()
      local pinfo = request('nvim_get_proc', pid)
      eq((iswin() and 'nvim.exe' or 'nvim'), pinfo.name)
      ok(pinfo.pid == pid)
      ok(type(pinfo.ppid) == 'number' and pinfo.ppid ~= pid)
    end)

    it('validates input', function()
      local status, rv = pcall(request, "nvim_get_proc", -1)
      eq(false, status)
      eq("Invalid pid: -1", string.match(rv, "Invalid.*"))

      status, rv = pcall(request, "nvim_get_proc", 0)
      eq(false, status)
      eq("Invalid pid: 0", string.match(rv, "Invalid.*"))

      -- Assume PID 99999 does not exist.
      status, rv = pcall(request, "nvim_get_proc", 99999)
      eq(true, status)
      eq(NIL, rv)
    end)
  end)
end)