RSpec::Memory

Make assertions about memory usage.

Installation

Add this line to your application's Gemfile:

gem 'rspec-memory'

And then execute:

$ bundle

Or install it yourself as:

$ gem install rspec-memory

Finally, add this require statement to the top of spec/spec_helper.rb

require 'rspec/memory'

Usage

Allocating large amounts of objects can lead to memory problems. RSpec::Memory adds a limit_allocations matcher, which tracks the number of allocations and memory size for each object type and allows you to specify expected limits.

RSpec.describe "memory allocations" do
    include_context RSpec::Memory

    it "limits allocation counts" do
        expect do
            6.times{String.new}
        end.to limit_allocations(String => 10) # 10 strings can be allocated
    end

    it "limits allocation counts (hash)" do
        expect do
            6.times{String.new}
        end.to limit_allocations(String => {count: 10}) # 10 strings can be allocated
    end

    it "limits allocation size" do
        expect do
            6.times{String.new("foo")}
        end.to limit_allocations(String => {size: 1024}) # 1 KB of strings can be allocated
    end
end

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

Released under the MIT license.

Copyright, 2017, by Samuel G. D. Williams.

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:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.