Allow ignore offences from YML file using load_ignore_config

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## master
 
+- [PR [#13](https://github.com/palkan/isolator/pull/13)] Allow load ignored offences from YML file using `load_ignore_config`. ([@DmitryTsepelev][])
+
 ## 0.3.0 (2018-04-02)
 
 - Add support for the [database_cleaner](https://github.com/DatabaseCleaner/database_cleaner) gem. ([@Envek][])
@@ -42,3 +44,4 @@
 [@TheSmartnik]: https://github.com/TheSmartnik
 [@dsalahutdinov]: https://github.com/dsalahutdinov
 [@Envek]: https://github.com/Envek
+[@DmitryTsepelev]: https://github.com/DmitryTsepelev

README.md

@@ -149,6 +149,22 @@ Isolator.adapters.sidekiq.ignore_if { Thread.current[:sidekiq_postpone] }
 
 You can add as many _ignores_ as you want, the offense is registered iff all of them return false.
 
+### Using with legacy Rails codebases
+
+If you already have a huge Rails project it can be a tricky to turn Isolator on because you'll immediately get a lot of failed specs. If you want to fix detected issues one by one, you can list all of them in the special file `.isolator_todo.yml` in a following way:
+
+```
+sidekiq:
+  - app/models/user.rb:20
+  - app/models/sales/**/*.rb
+```
+
+All the exceptions raised in the listed lines will be ignored.
+
+### Using with legacy Ruby codebases
+
+If you are not using Rails, you'll have to load ignores from file manually, using `Isolator#load_ignore_config`, for instance `Isolator.load_ignore_config("./config/.isolator_todo.yml")`
+
 ## Custom Adapters
 
 An adapter is just a combination of a _method wrapper_ and lifecycle hooks.

lib/isolator.rb

@@ -6,6 +6,7 @@
 require "isolator/notifier"
 require "isolator/errors"
 require "isolator/simple_hashie"
+require "isolator/ignorer"
 
 require "isolator/callbacks"
 require "isolator/isolate"
@@ -105,6 +106,7 @@ def adapters
 
     include Isolator::Isolate
     include Isolator::Callbacks
+    include Isolator::Ignorer
   end
 end
 

lib/isolator/ignorer.rb

@@ -0,0 +1,39 @@
+# frozen_string_literal: true
+
+module Isolator
+  # Add .load_ignore_config function for ignoring patterns from file
+  module Ignorer
+    def load_ignore_config(path)
+      return unless File.exist?(path)
+
+      todos = YAML.load_file(path)
+
+      adapters.each do |id, adapter|
+        ignored_paths = todos.fetch(id, [])
+        configure_adapter(adapter, ignored_paths)
+      end
+    end
+
+    private
+
+    def configure_adapter(adapter, ignored_paths)
+      ignores = build_ignore_list(ignored_paths)
+      return if ignores.blank?
+
+      regex = Regexp.new("^.*(#{ignores.join('|')}):.*$")
+      adapter.ignore_if { caller.any? { |row| regex =~ row } }
+    end
+
+    def build_ignore_list(ignored_paths)
+      ignored_paths.each_with_object([]) do |path, result|
+        ignored_files = Dir[path]
+
+        if ignored_files.blank?
+          result << path.to_s
+        else
+          result.concat(ignored_files)
+        end
+      end
+    end
+  end
+end

lib/isolator/railtie.rb

@@ -7,6 +7,8 @@ class Railtie < ::Rails::Railtie # :nodoc:
       # (when all deps are likely to be loaded).
       load File.join(__dir__, "adapters.rb")
 
+      Isolator.load_ignore_config(Rails.root.join(".isolator_todo.yml"))
+
       next unless Rails.env.test?
 
       if defined?(::ActiveRecord::TestFixtures)

spec/isolator/ignorer_spec.rb

@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+require "spec_helper"
+
+describe "Ignorer" do
+  TODO_PATH = ".isolator_todo.yml"
+
+  before(:all) do
+    module ::Isolator::Danger # rubocop:disable Style/ClassAndModuleChildren
+      def self.call_masked(a, b)
+        a + b
+      end
+
+      def self.call_unmasked(a, b)
+        a + b
+      end
+    end
+
+    Isolator.isolate :todo_masked_adapter,
+                     target: ::Isolator::Danger.singleton_class,
+                     method_name: :call_masked
+
+    Isolator.isolate :todo_unmasked_adapter,
+                     target: ::Isolator::Danger.singleton_class,
+                     method_name: :call_unmasked
+  end
+
+  after(:all) do
+    Isolator.send(:remove_const, "Danger")
+    Isolator.adapters.delete("todo_masked_adapter")
+    Isolator.adapters.delete("todo_unmasked_adapter")
+  end
+
+  before do
+    allow(Isolator).to receive(:within_transaction?) { true }
+  end
+
+  subject { ::Isolator::Danger }
+
+  specify do
+    expect { subject.call_masked(1, 2) }.to raise_error(Isolator::UnsafeOperationError)
+    expect { subject.call_unmasked(1, 2) }.to raise_error(Isolator::UnsafeOperationError)
+  end
+
+  context "unmasked todos" do
+    before(:each) do
+      allow(File).to receive(:exist?).with(TODO_PATH).and_return(true)
+
+      allow(YAML).to receive(:load_file).with(TODO_PATH).and_return(
+        "todo_unmasked_adapter" => ["spec/isolator/ignorer_spec.rb:58"],
+        "wrong_adapter" => ["spec/isolator/ignorer_spec.rb:62"]
+      )
+
+      Isolator.load_ignore_config(TODO_PATH)
+    end
+
+    it "doesn't raise when ignored" do
+      expect { subject.call_unmasked(1, 2) }.not_to raise_error
+    end
+
+    it "raise when wrong operator is ignored" do
+      expect { subject.call_unmasked(1, 2) }.to raise_error
+    end
+  end
+
+  context "masked todos" do
+    before(:each) do
+      allow(File).to receive(:exist?).with(TODO_PATH).and_return(true)
+
+      allow(YAML).to receive(:load_file).with(TODO_PATH).and_return(
+        "todo_masked_adapter" => ["spec/isolator/**/*.rb"]
+      )
+
+      Isolator.load_ignore_config(TODO_PATH)
+    end
+
+    it "doesn't raise when ignored via mask" do
+      expect { subject.call_masked(1, 2) }.not_to raise_error
+    end
+  end
+end