side_effects.lua

-- in a it/describe block you can do this to simulate a side-effect
-- similar to python-unittest's side_effect https://docs.python.org/3/library/unittest.mock.html#unittest.mock.Mock.side_effect

local called = false
local side_effect = function()
  -- adding a side_effect that causes to fail the `request_uri` the first time
  -- but succeed the second time.
  if not called then
    called = true
    return false, "err"
  end
  return true, nil
end

local s_request_uri = stub(httpc, "request_uri").invokes(side_effect)