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

We welcome contributions to this project.

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.