Test

local ADDON_PREFIX = "Test"
local REQUEST_RESPONSE = "REQ_RESPONSE"
local RESPONSE = "RESPONSE"
local playerName = GetUnitName("player", false)
local frame = CreateFrame("Frame")

local function EventHandler(self, event, ...)
  if event=="ADDON_LOADED" then
    name = ...
    if name == "Test" then  -- If this addon was loaded, send an addon message to yourself
      print("Send request")
      SendAddonMessage(ADDON_PREFIX, REQUEST_RESPONSE, WHISPER, playerName)
    end
  elseif event == "CHAT_MSG_ADDON" then
    local prefix, message, channel, sender = ...
    print("Received " .. message .. " from " .. sender)
    if message == REQUEST_RESPONSE then -- If a request message was received, send a response
      SendAddonMessage(ADDON_PREFIX, RESPONSE, WHISPER, sender)
    end

  end

end

-- Register events
frame:RegisterEvent("ADDON_LOADED")
frame:RegisterEvent("CHAT_MSG_ADDON")
local succes = RegisterAddonMessagePrefix(ADDON_PREFIX)
if not succes then
  print("Test: Failed to register addon message prefix " .. ADDON_PREFIX)
end
frame:SetScript("OnEvent", EventHandler)

-- Register slash command
SLASH_TEST1 = "/test"
SlashCmdList["TEST"] = function()
  print("Send request")
  SendAddonMessage(ADDON_PREFIX, REQUEST_RESPONSE, WHISPER, playerName)
end