Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Testing Asynchronous OTP
Search
Andrea Leopardi
September 09, 2021
Programming
1
520
Testing Asynchronous OTP
Andrea Leopardi
September 09, 2021
Tweet
Share
More Decks by Andrea Leopardi
See All by Andrea Leopardi
gen_statem - OTP's Unsung Hero
whatyouhide
2
250
The World is a Network (and We Are Just Nodes)
whatyouhide
1
220
BEAM: The Perfect Fit for Networks
whatyouhide
1
200
Update from the Elixir team - 2022
whatyouhide
0
400
Elixir Sightseeing Tour
whatyouhide
0
420
Mint - Disrupting HTTP clients
whatyouhide
0
250
BEAM Architecture Handbook
whatyouhide
7
2.8k
The Evolution of a Language
whatyouhide
0
160
Elixir - functional, concurrent, distributed programming for the rest of us
whatyouhide
2
330
Other Decks in Programming
See All in Programming
明示と暗黙 ー PHPとGoの インターフェイスの違いを知る
shimabox
2
280
Elixir で IoT 開発、 Nerves なら簡単にできる!?
pojiro
1
150
ASP.NETアプリケーションのモダナイズ インフラ編
tomokusaba
1
410
AWS CDKの推しポイント 〜CloudFormationと比較してみた〜
akihisaikeda
3
310
Webの外へ飛び出せ NativePHPが切り拓くPHPの未来
takuyakatsusa
2
320
PHP 8.4の新機能「プロパティフック」から学ぶオブジェクト指向設計とリスコフの置換原則
kentaroutakeda
2
470
「ElixirでIoT!!」のこれまでとこれから
takasehideki
0
370
関数型まつり2025登壇資料「関数プログラミングと再帰」
taisontsukada
2
850
Julia という言語について (FP in Julia « SIDE: F ») for 関数型まつり2025
antimon2
3
980
Create a website using Spatial Web
akkeylab
0
300
[初登壇@jAZUG]アプリ開発者が気になるGoogleCloud/Azure+wasm/wasi
asaringo
0
130
Blazing Fast UI Development with Compose Hot Reload (droidcon New York 2025)
zsmb
1
190
Featured
See All Featured
BBQ
matthewcrist
89
9.7k
Speed Design
sergeychernyshev
32
1k
Building Applications with DynamoDB
mza
95
6.5k
[RailsConf 2023 Opening Keynote] The Magic of Rails
eileencodes
29
9.5k
4 Signs Your Business is Dying
shpigford
184
22k
Designing Experiences People Love
moore
142
24k
Making the Leap to Tech Lead
cromwellryan
134
9.3k
The Cost Of JavaScript in 2023
addyosmani
51
8.4k
Save Time (by Creating Custom Rails Generators)
garrettdimon
PRO
31
1.2k
Responsive Adventures: Dirty Tricks From The Dark Corners of Front-End
smashingmag
252
21k
ReactJS: Keep Simple. Everything can be a component!
pedronauck
667
120k
Code Review Best Practice
trishagee
68
18k
Transcript
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
None
defmodule RollingAverage do use GenServer def start_link(limit), do: # ...
def add(pid, n), do: # ... def average(pid), do: # ... end
None
None
test "add/2" do {:ok, pid} = RollingAverage.start_link() RollingAverage.add(pid, 3) #
Now what? end
None
test "add/2 and average/1" do {:ok, pid} = RollingAverage.start_link(2) RollingAverage.add(pid,
3) RollingAverage.add(pid, 4) assert RollingAverage.average(pid) == 3.5 RollingAverage.add(pid, 5) assert RollingAverage.average(pid) == 4.5 end
None
defmodule RollingList do def new(limit), do: {limit, []} def add({limit,
list}, n), do: # ... def average({_limit, list}), do: # ... end
test "add/2" do rolling_list = RollingList.new(2) assert RollingList.add(rolling_list, 3) ==
{_limit = 2, [3]} end
None
test "add/2" do {:ok, pid} = RollingAverage.start_link(2) RollingAverage.add(pid, 3) state
= :sys.get_state(pid) assert state == {_limit = 2, [3]} end
None
None
test "add/2 and average/1" do {:ok, pid} = start_supervised( {RollingAverage,
_limit = 2} ) # Same as before end
None
def background_work do Task.start(fn -> do_something() end) end
None
None
def background_work(parent, ref) do Task.start(fn -> do_something() send(parent, {ref, :done})
end) end
test "background_work/0" do ref = make_ref() background_work(self(), ref) assert_receive {^ref,
:done} end
None
def background_work do Task.start(fn -> :ok = twitter_module.post() end) end
test "background_work/0" do parent = self() ref = make_ref() Mox.expect(TwitterMock,
:post, fn -> send(parent, ref) :ok end) background_work() assert_receive ^ref end
None
defmodule WeatherChecker do use GenServer def init(_) do :timer.send_interval(5000, self(),
:tick) end def handle_info(:tick, _) do check_weather() end end
test "checking weather periodically" do {:ok, _pid} = WeatherChecker.start_link() Process.sleep(5000
* 1.5) assert weather_checked?() end
None
defmodule WeatherChecker do use GenServer def init(_) do :timer.send_interval(5000, self(),
:tick) end def tick(pid), do: send(pid, :tick) def handle_info(:tick, _) do check_weather() end end
test "checking weather periodically" do {:ok, pid} = WeatherChecker.start_link() WeatherChecker.tick(pid)
assert weather_checked?() end
defmodule WeatherChecker do use GenServer def init(:interval) do :timer.send_interval(5000, self(),
:tick) end def init(:manual) do # No send_interval end end
None
@mix_env Mix.env() def start(_type, _args) do Supervisor.start_link(children(@mix_env), ...) end defp
children(:test), do: [...] defp children(_env), do: [WeatherChecker | ...]
None
None
None
None
test "cleanup after crashes" do Process.flag(:trap_exit, true) {:ok, pid} =
start_supervised(MyServer) Process.exit(pid, :kill) assert cleanup_successful?() end
None
None
None
None
None
None
None
None
None
None