check for non-concurrent indexes

README.md

@@ -18,6 +18,12 @@ TODO: Write usage instructions here
 
 ## Development
 
+For running the spec files, this project depends on RuboCop's spec helpers. This means that in order to run the specs locally, you need a (shallow) clone of the RuboCop repository:
+
+```
+git clone --depth 1 git://github.com/bbatsov/rubocop.git vendor/rubocop
+```
+
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.
 
 To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org).

circle.yml

@@ -0,0 +1,6 @@
+machine:
+  ruby:
+    version: 2.3.0
+dependencies:
+  pre:
+    - git clone --depth 1 git://github.com/bbatsov/rubocop.git vendor/rubocop

egad.gemspec

@@ -33,4 +33,5 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rspec-its"
   spec.add_development_dependency "rspec-collection_matchers"
   spec.add_development_dependency "rspec_junit_formatter", "~> 0.2"
+  spec.add_development_dependency "pry"
 end

lib/egad.rb

@@ -3,7 +3,7 @@
 require "rubocop"
 
 require "rubocop/egad/version"
-require "rubocop/cop/egad/add_index"
+require "rubocop/cop/egad/add_index_non_concurrently"
 
 module RuboCop
   module Egad

lib/rubocop/cop/egad/add_index_non_concurrently.rb

@@ -0,0 +1,36 @@
+module RuboCop
+  module Cop
+    module Egad
+      class AddIndexNonConcurrently < Cop
+        MSG = 'Use `algorithm: :concurrently` to avoid locking database.'.freeze
+
+        def_node_matcher :add_index_or_add_reference?, <<-PATTERN
+          (send nil {:add_index :add_reference} ...)
+        PATTERN
+
+        def on_send(node)
+          if add_index_or_add_reference?(node)
+            options = options_hash(node)
+            if !options[:algorithm].present? || options[:algorithm] != "concurrently"
+              add_offense(node, :expression, MSG)
+            end
+          end
+        end
+
+        private
+
+        def options_hash(node)
+          options = {}
+          node.children.each do |c|
+            if c.is_a?(AST::Node) && c.type == :hash
+              c.each_pair do |key_node, value_node|
+                options[key_node.children.first.to_sym] = value_node.children.first.to_s
+              end
+            end
+          end
+          options
+        end
+      end
+    end
+  end
+end

spec/rubocop/cop/egad/add_index_non_concurrently_spec.rb

@@ -0,0 +1,45 @@
+describe RuboCop::Cop::Egad::AddIndexNonConcurrently do
+  subject(:cop) { described_class.new }
+
+  before do
+    inspect_source(cop, source)
+  end
+
+  context "add_index" do
+    context "basic source, non-concurrent" do
+      let(:source) { "add_index :users, :some_column" }
+
+      it "registers an offense" do
+        expect(cop.offenses.size).to eq(1)
+        expect(cop.offenses.first.message).to eq("Use `algorithm: :concurrently` to avoid locking database.")
+        expect(cop.highlights).to eq([source])
+      end
+    end
+
+    context "complex source, non-concurrent" do
+      let(:source) { "add_index :users, [:some_column, :another], unique: true, algorithm: :btree, something: {nested: 1}" }
+
+      it "registers an offense" do
+        expect(cop.offenses.size).to eq(1)
+        expect(cop.offenses.first.message).to eq("Use `algorithm: :concurrently` to avoid locking database.")
+        expect(cop.highlights).to eq([source])
+      end
+    end
+
+    context "basic source, concurrent" do
+      let(:source) { "add_index :users, :some_column, algorithm: :concurrently" }
+
+      it "doesn't register an offense" do
+        expect(cop.offenses).to be_empty
+      end
+    end
+
+    context "complex source, concurrent" do
+      let(:source) { "add_index :users, [:some_column, :another], unique: true, algorithm: 'concurrently', something: {nested: 1}" }
+
+      it "doesn't register an offense" do
+        expect(cop.offenses).to be_empty
+      end
+    end
+  end
+end

spec/spec_helper.rb

@@ -2,6 +2,16 @@
 require "egad"
 require "rspec/collection_matchers"
 require "rspec/its"
+require 'rubocop'
+require 'pry' unless ENV["CI"]
+
+rubocop_path = File.join(File.dirname(__FILE__), '../vendor/rubocop')
+unless File.directory?(File.join(rubocop_path, '.git'))
+  raise("Can't run specs without a local RuboCop checkout. Look in the README.")
+end
+Dir["#{rubocop_path}/spec/support/**/*.rb"].each { |f| require f }
+require 'rubocop/rspec/support'
+
 
 RSpec.configure do |config|
   # Enable flags like --only-failures and --next-failure