A simple rack middleware to add a random delay for requests, so you can simulate network latency during development. This library works with any rack capable framework, so you can use with sinatra or rails or whatever you want.
You can install this library via gem
gem install rack-delay
or via Bundler adding
gem 'rack-delay'
to your Gemfile and install:
bundle install
To use rack-delay simply add it in config.ru file. Below is an example of middleware:
# config.ru
require 'rack/delay'
use Rack::Delay
app = proc do |env|
[ 200, {'Content-Type' => 'text/plain'}, "b" ]
end
run app
Rack-delay when use without options, will add a random delay to every request. You probably want to customize this behaviour, so you can pass options to middleware ex:
# config.ru
require 'rack/delay'
use Rack::Delay, {
:min => 0, # ms
:max => 5000, # ms
:if => lambda { |request|
request.xhr?
}
}
app = proc do |env|
[ 200, {'Content-Type' => 'text/plain'}, "b" ]
end
run app
In previous example rack-delay will add a random delay (between :min/:max) to every ajax requests.
Also you can do more complex things like use a different delay for different requests, ex:
# config.ru
require 'rack/delay'
use Rack::Delay, {
:delay => lambda { |request|
if request.get? # fixed 100ms delay to every get request
[100]
elsif request.post? # 300ms - 3sec delay to every post request
[300, 3000]
else
[0, rand(5000)] # use a random delay
end
# if you not return a number from this block, rack-delay will use defaults range :min/:max to calc random delay
},
:if => lambda { |request|
request.xhr? and request.ip == '127.0.0.1'
}
}
app = proc do |env|
[ 200, {'Content-Type' => 'text/plain'}, "b" ]
end
run app
Here a list of options which rack-delay can understand.
-
:min / :max
Specifies range in msec of random delay. When :min == :max delay will be fixed -
:delay
Another way to customize delay generation. Value returned by block can be a single number or 2 item array.
When a number, then the request will be slowdown exactly by that number msec.
If returns 2 items array (eg. [min, max]), then will be used to build range. -
:if / :unless
Used to control activation of rack-delay.
Copyright (c) 2013 Vincenzo Farruggia.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
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