View registry.ex
defmodule Registry do
# ...
def handle_call({:execute_against_shard, campaign_id, fun}, from, state) do
{shard_process, state} = find_or_create_shard(campaign_id, state)
ShardProcess.execute_and_reply(shard_process, fun, from)
{:noreply, state}
# ...
View Rakefile
require 'rspec/core/rake_task' do |t|
t.rspec_opts = "--out tmp/specs_task.out"
task :specs => :specs_prep do
results ="tmp/specs_task.out")
# do something with results
View inverse_hook_filtering.rb
RSpec.configure do |config|
# Either put conditional logic in the hook...
config.around(:example) do |ex|
unless ex.metadata[:slow]
puts "Not tagged slow"
View rspec_output.txt
A group of examples
 is pending (PENDING: not yet passing)
 fails (FAILED - 1)
 fails with a diff (FAILED - 2)
 fails with a multiline snippet in order to show off syntax highlighting (FAILED - 3)
Pending: (Failures listed here are expected and do not affect your suite's status)
View response.txt
HTTP/1.1 400 Bad Request
connection: close
server: Cowboy
date: Tue, 24 Nov 2015 20:24:58 GMT
content-length: 0

Using OTP's observer (appmon replacement) remotely

$ ssh remote-host "epmd -names"
epmd: up and running on port 4369 with data:
name some_node at port 58769

Note the running on port for epmd itself and the port of the node you're interested in debugging. Reconnect to the remote host with these ports forwarded:

$ ssh -L 4369:localhost:4369 -L 58769:localhost:58769 remote-host
View supervisor.ex
defmodule Delorean.RankingsShardRepository.RunningShard.Supervisor do
use Supervisor
def start_link(opts) do
Supervisor.start_link(__MODULE__, opts, [])
def start_shard(supervisor, shard_opts) do
Supervisor.start_child(supervisor, shard_opts)
View snapshot_repository_test.exs
defmodule MyApp.SnapshotRepositoryTest do
use ExUnit.Case, async: true
doctest MyApp.SnapshotRepository
alias MyApp.SnapshotRepository.SnapshotOptions
test "queries S3 with a prefix and returns the matched keys" do
options = %SnapshotOptions{ campaign_id: "prod.0.1", backend: "SomeBackend", cycle_type: "week" }
prefix = SnapshotOptions.to_key_prefix(options)
key_1 = "#{prefix}0/2013-03-19T15:04:50Z/mtoken.json.gz"
key_2 = "#{prefix}1/2013-03-19T15:04:50Z/mtoken.json.gz"
View parallel.ex
defmodule Delorean.Parallel do
def map(list, fun) do
|> -> Task.async(fn -> fun.(item) end) end)
View named_doubles.rb
# to get the name, you can use `instance_variable_get`:
tweet = double("Twitter::Tweet")
tweet.instance_variable_get(:@name) # => "Twitter::Tweet"
# that's clearly violating the public API, though. Another way is to pass it as a stub:
tweet = double("Twitter::Tweet", name: "Twitter::Tweet") # => "Twitter::Tweet"
# If you like that approach, you could create a new `named_double`
# helper method: