init

.rspec

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+--color
+--require spec_helper

Gemfile

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+source 'https://rubygems.org'
+
+gem 'redis', '~>3.2'
+gem 'rspec', '~> 3.0'

Gemfile.lock

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+GEM
+  remote: https://rubygems.org/
+  specs:
+    diff-lcs (1.2.5)
+    redis (3.3.0)
+    rspec (3.4.0)
+      rspec-core (~> 3.4.0)
+      rspec-expectations (~> 3.4.0)
+      rspec-mocks (~> 3.4.0)
+    rspec-core (3.4.4)
+      rspec-support (~> 3.4.0)
+    rspec-expectations (3.4.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.4.0)
+    rspec-mocks (3.4.1)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.4.0)
+    rspec-support (3.4.1)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  redis (~> 3.2)
+  rspec (~> 3.0)

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2016 Travis CI GmbH
+
+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.

Makefile

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+.PHONY: test
+test:
+	bundle exec rspec
+
+.PHONY: install
+install:
+	bundle install

README.md

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+# travis-feierabend
+
+Unused code detection modeled after David Schnepper's talk (https://www.youtube.com/watch?v=29UXzfQWOhQ).
+
+## usage
+
+    require 'travis/feierabend'
+    require 'travis/feierabend/redis_storage'
+
+    Travis::Feierabend.configure { Travis::Feierabend::RedisStorage.new(config) }
+    Travis::Feierabend.place('2016-07-01/old-smelly-code')
+
+    Travis::Feierabend.list_in_use('2016-07-01/old-smelly-code')
+
+## install
+
+    $ make install
+
+## test
+
+    $ make

lib/travis/feierabend.rb

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+require 'json'
+
+module Travis
+  class Feierabend
+    attr_reader :storage
+
+    def initialize(storage)
+      @storage = storage
+    end
+
+    def place(label, meta={})
+      data = {
+        trace: Kernel.caller_locations.join("\n"),
+        meta: meta,
+      }
+      @storage.store(label, JSON.dump(data))
+    end
+
+    def list_in_use(label)
+      @storage.list_in_use(label).map { |r| JSON.parse(r) }
+    end
+
+    class << self
+      def configure(&block)
+        @storage_factory = block
+        @storage = nil
+        @instance = nil
+      end
+
+      def storage
+        if @storage_factory.nil?
+          raise RuntimeError.new('tried to access global Travis::Feierabend without configuring it')
+        end
+        @storage ||= @storage_factory.call
+      end
+
+      def instance
+        @instance ||= Feierabend.new(storage)
+      end
+
+      def place(label, meta={})
+        instance.place(label, meta)
+      end
+
+      def list_in_use(label)
+        instance.list_in_use(label)
+      end
+    end
+  end
+end

lib/travis/feierabend/memory_storage.rb

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+module Travis
+  class Feierabend
+    class MemoryStorage
+      def initialize
+        @in_use = {}
+      end
+
+      def store(label, data)
+        @in_use[label] ||= []
+        @in_use[label].push(data)
+      end
+
+      def list_in_use(label)
+        @in_use[label] || []
+      end
+    end
+  end
+end

lib/travis/feierabend/redis_storage.rb

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+require 'redis'
+
+module Travis
+  class Feierabend
+    class RedisStorage
+      attr_reader :redis
+
+      def initialize(config={})
+        @prefix = config[:prefix] || 'Feierabend:in_use:'
+        @max_length = config[:max_length] || 500
+        @redis = Redis.new(config[:redis] || {})
+      end
+
+      def store(label, trace)
+        @redis.multi do
+          @redis.rpush(@prefix+label, trace)
+          @redis.ltrim(@prefix+label, 0, @max_length)
+        end
+      end
+
+      def list_in_use(label)
+        @redis.lrange(@prefix+label, 0, @max_length).reverse
+      end
+    end
+  end
+end

spec/spec_helper.rb

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+# This file was generated by the `rspec --init` command. Conventionally, all
+# specs live under a `spec` directory, which RSpec adds to the `$LOAD_PATH`.
+# The generated `.rspec` file contains `--require spec_helper` which will cause
+# this file to always be loaded, without a need to explicitly require it in any
+# files.
+#
+# Given that it is always loaded, you are encouraged to keep this file as
+# light-weight as possible. Requiring heavyweight dependencies from this file
+# will add to the boot time of your test suite on EVERY test run, even for an
+# individual file that may not need all of that loaded. Instead, consider making
+# a separate helper file that requires the additional dependencies and performs
+# the additional setup, and require it from the spec files that actually need
+# it.
+#
+# The `.rspec` file also contains a few flags that are not defaults but that
+# users commonly want.
+#
+# See http://rubydoc.info/gems/rspec-core/RSpec/Core/Configuration
+RSpec.configure do |config|
+  # rspec-expectations config goes here. You can use an alternate
+  # assertion/expectation library such as wrong or the stdlib/minitest
+  # assertions if you prefer.
+  config.expect_with :rspec do |expectations|
+    # This option will default to `true` in RSpec 4. It makes the `description`
+    # and `failure_message` of custom matchers include text for helper methods
+    # defined using `chain`, e.g.:
+    #     be_bigger_than(2).and_smaller_than(4).description
+    #     # => "be bigger than 2 and smaller than 4"
+    # ...rather than:
+    #     # => "be bigger than 2"
+    expectations.include_chain_clauses_in_custom_matcher_descriptions = true
+  end
+
+  # rspec-mocks config goes here. You can use an alternate test double
+  # library (such as bogus or mocha) by changing the `mock_with` option here.
+  config.mock_with :rspec do |mocks|
+    # Prevents you from mocking or stubbing a method that does not exist on
+    # a real object. This is generally recommended, and will default to
+    # `true` in RSpec 4.
+    mocks.verify_partial_doubles = true
+  end
+
+# The settings below are suggested to provide a good initial experience
+# with RSpec, but feel free to customize to your heart's content.
+=begin
+  # These two settings work together to allow you to limit a spec run
+  # to individual examples or groups you care about by tagging them with
+  # `:focus` metadata. When nothing is tagged with `:focus`, all examples
+  # get run.
+  config.filter_run :focus
+  config.run_all_when_everything_filtered = true
+
+  # Allows RSpec to persist some state between runs in order to support
+  # the `--only-failures` and `--next-failure` CLI options. We recommend
+  # you configure your source control system to ignore this file.
+  config.example_status_persistence_file_path = "spec/examples.txt"
+
+  # Limits the available syntax to the non-monkey patched syntax that is
+  # recommended. For more details, see:
+  #   - http://rspec.info/blog/2012/06/rspecs-new-expectation-syntax/
+  #   - http://www.teaisaweso.me/blog/2013/05/27/rspecs-new-message-expectation-syntax/
+  #   - http://rspec.info/blog/2014/05/notable-changes-in-rspec-3/#zero-monkey-patching-mode
+  config.disable_monkey_patching!
+
+  # This setting enables warnings. It's recommended, but in some cases may
+  # be too noisy due to issues in dependencies.
+  config.warnings = true
+
+  # Many RSpec users commonly either run the entire suite or an individual
+  # file, and it's useful to allow more verbose output when running an
+  # individual spec file.
+  if config.files_to_run.one?
+    # Use the documentation formatter for detailed output,
+    # unless a formatter has already been configured
+    # (e.g. via a command-line flag).
+    config.default_formatter = 'doc'
+  end
+
+  # Print the 10 slowest examples and example groups at the
+  # end of the spec run, to help surface which specs are running
+  # particularly slow.
+  config.profile_examples = 10
+
+  # Run specs in random order to surface order dependencies. If you find an
+  # order dependency and want to debug it, you can fix the order by providing
+  # the seed, which is printed after each run.
+  #     --seed 1234
+  config.order = :random
+
+  # Seed global randomization in this process using the `--seed` CLI option.
+  # Setting this allows you to use `--seed` to deterministically reproduce
+  # test failures related to randomization by passing the same `--seed` value
+  # as the one that triggered the failure.
+  Kernel.srand config.seed
+=end
+end

spec/tombstone_spec.rb

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+require 'travis/feierabend'
+require 'travis/feierabend/memory_storage'
+require 'travis/feierabend/redis_storage'
+
+RSpec.describe Travis::Feierabend, "#place" do
+  context "memory storage" do
+    before {
+      Travis::Feierabend.configure { Travis::Feierabend::MemoryStorage.new }
+    }
+
+    it "stores a refutation" do
+     Travis::Feierabend.place('2016-07-01/test-case')
+     expect(Travis::Feierabend.get_refutations('2016-07-01/test-case').count).to be(1)
+   end
+  end
+
+  context "redis storage" do
+    before {
+      Travis::Feierabend.configure { Travis::Feierabend::RedisStorage.new }
+
+      redis = Travis::Feierabend.storage.redis
+      redis.keys('feierabend:in_use:*').each do |key|
+        redis.del(key)
+      end
+    }
+
+    it "stores a refutation" do
+     Travis::Feierabend.place('2016-07-01/test-case')
+     expect(Travis::Feierabend.get_refutations('2016-07-01/test-case').count).to be(1)
+   end
+  end
+end

travis-feierabend.gemspec

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+Gem::Specification.new do |s|
+  s.name        = 'travis-feierabend'
+  s.version     = '1.0.0'
+  s.date        = '2016-06-01'
+  s.summary     = "Feierabend"
+  s.description = "Unused code detection modeled after David Schnepper's talk (https://www.youtube.com/watch?v=29UXzfQWOhQ)"
+  s.authors     = ["Igor Wiedler"]
+  s.email       = '[email protected]'
+  s.files       = ["lib/travis/feierabend.rb"]
+  s.homepage    = 'http://rubygems.org/gems/travis-Feierabend'
+  s.license     = 'MIT'
+end