Merge pull request ginty#7 from beorc/lint

Add factories linter

README.md

@@ -217,6 +217,66 @@ def users_collection
 end
 ~~~
 
+## Linting Factories
+
+Cranky allows for linting known factories:
+
+~~~ruby
+Factory.lint!
+~~~
+
+`Factory.lint!` creates each factory and catches any exceptions raised during the creation process. `Cranky::Linter::InvalidFactoryError` is raised with a list of factories (and corresponding exceptions) for factories which could not be created.
+
+Recommended usage of `Factory.lint!` is to run this in a task before your test suite is executed. Running it in a `before(:suite)`, will negatively impact the performance of your tests when running single tests.
+
+Example Rake task:
+
+~~~ruby
+# lib/tasks/factory_girl.rake
+namespace :cranky do
+  desc "Verify that all factories are valid"
+  task lint: :environment do
+    if Rails.env.test?
+      begin
+        DatabaseCleaner.start
+        Factory.lint!
+      ensure
+        DatabaseCleaner.clean
+      end
+    else
+      system("bundle exec rake cranky:lint RAILS_ENV='test'")
+    end
+  end
+end
+~~~
+
+After calling `Factory.lint!`, you'll likely want to clear out the database, as records will most likely be created. The provided example above uses the database_cleaner gem to clear out the database; be sure to add the gem to your Gemfile under the appropriate groups.
+
+You can lint factories selectively by passing only factories you want linted:
+
+~~~ruby
+factories_to_lint = Factory.factory_names.reject do |name|
+  name =~ /^old_/
+end
+
+Factory.lint! factories_to_lint
+~~~
+
+This would lint all factories that aren't prefixed with `old_`.
+
+Traits can also be linted. This option verifies that each
+and every trait of a factory generates a valid object on its own. This is turned on by passing traits: true to the lint method:
+
+~~~ruby
+Factory.lint! traits: true
+~~~
+
+This can also be combined with other arguments:
+
+~~~ruby
+Factory.lint! factories_to_lint, traits: true
+~~~
+
 ## Helpers
 
 Of course its nice to get some help...

lib/cranky.rb

@@ -1,5 +1,6 @@
 require 'cranky/version'
 require 'cranky/job'
+require 'cranky/linter'
 require 'cranky/factory'
 
 # Instantiate a factory, this enables an easy drop in for tests written for Factory Girl  

lib/cranky/factory.rb

@@ -1,7 +1,7 @@
 module Cranky
-  class Factory
+  class FactoryBase
 
-    attr_writer :debug
+    TRAIT_METHOD_REGEXP = /apply_trait_(\w+)_to_(\w+)/.freeze
 
     def initialize
       # Factory jobs can be nested, i.e. a factory method can itself invoke another factory method to
@@ -22,6 +22,12 @@ def create(what, overrides={})
       item
     end
 
+    def create!(what, overrides={})
+      item = build(what, overrides)
+      Array(item).each(&:save!)
+      item
+    end
+
     # Reset the factory instance, clear all instance variables
     def reset
       self.instance_variables.each do |var|
@@ -57,6 +63,27 @@ def debug!(*args)
       item
     end
 
+    # Look for errors in factories and (optionally) their traits.
+    # Parameters:
+    # factory_names - which factories to lint; omit for all factories
+    # options:
+    #   traits : true - to lint traits as well as factories
+    def lint!(factory_names: nil, traits: false)
+      factories_to_lint = Array(factory_names || self.factory_names)
+      strategy = traits ? :factory_and_traits : :factory
+      Linter.new(self, factories_to_lint, strategy).lint!
+    end
+
+    def factory_names
+      public_methods(false).reject {|m| TRAIT_METHOD_REGEXP === m  }
+    end
+
+    def traits_for(factory_name)
+      regexp = /^apply_trait_(\w+)_to_#{factory_name}$/.freeze
+      trait_methods = public_methods(false).select {|m| regexp === m  }
+      trait_methods.map {|m| regexp.match(m)[1] }
+    end
+
     private
 
       def apply_traits(what, item)
@@ -118,5 +145,7 @@ def new_job(what, overrides)
 
   end
 
-end
+  class Factory < FactoryBase
+  end
 
+end

lib/cranky/linter.rb

@@ -0,0 +1,101 @@
+module Cranky
+  class Linter
+
+    def initialize(factory, factories_to_lint, linting_strategy)
+      @factory = factory
+      @factories_to_lint = factories_to_lint
+      @linting_method = "lint_#{linting_strategy}"
+      @invalid_factories = calculate_invalid_factories
+    end
+
+    def lint!
+      if invalid_factories.any?
+        raise InvalidFactoryError, error_message
+      end
+    end
+
+    attr_reader :factories_to_lint, :invalid_factories
+    private :factories_to_lint, :invalid_factories
+
+    private
+
+    def calculate_invalid_factories
+      factories_to_lint.reduce(Hash.new([])) do |result, factory|
+        errors = send(@linting_method, factory)
+        result[factory] |= errors unless errors.empty?
+        result
+      end
+    end
+
+    # Raised when any factory is considered invalid
+    class InvalidFactoryError < RuntimeError; end
+
+    class FactoryError
+      def initialize(wrapped_error, factory_name)
+        @wrapped_error = wrapped_error
+        @factory_name  = factory_name
+      end
+
+      def message
+        message = @wrapped_error.message
+        "* #{location} - #{message} (#{@wrapped_error.class.name})"
+      end
+
+      def location
+        @factory_name
+      end
+    end
+
+    class FactoryTraitError < FactoryError
+      def initialize(wrapped_error, factory_name, trait_name)
+        super(wrapped_error, factory_name)
+        @trait_name = trait_name
+      end
+
+      def location
+        "#{@factory_name}+#{@trait_name}"
+      end
+    end
+
+    def lint_factory(factory_name)
+      result = []
+      begin
+        @factory.create!(factory_name)
+      rescue => error
+        result |= [FactoryError.new(error, factory_name)]
+      end
+      result
+    end
+
+    def lint_traits(factory_name)
+      result = []
+      @factory.traits_for(factory_name).each do |trait_name|
+        begin
+          @factory.create!(factory_name, traits: trait_name)
+        rescue => error
+          result |=
+              [FactoryTraitError.new(error, factory_name, trait_name)]
+        end
+      end
+      result
+    end
+
+    def lint_factory_and_traits(factory_name)
+      errors = lint_factory(factory_name)
+      errors |= lint_traits(factory_name)
+      errors
+    end
+
+    def error_message
+      lines = invalid_factories.map do |_factory, exceptions|
+        exceptions.map(&:message)
+      end.flatten
+
+      <<-ERROR_MESSAGE.strip
+The following factories are invalid:
+
+#{lines.join("\n")}
+      ERROR_MESSAGE
+    end
+  end
+end

spec/cranky_spec.rb

@@ -2,7 +2,44 @@
 
 describe "The Cranky factory" do
 
-  before(:each) do
+  describe '#factory_names' do
+    it 'returns an array of names of defined factories' do
+      Factory.factory_names.should eq [:user,
+                                       :address,
+                                       :users_collection,
+                                       :user_manually,
+                                       :user_by_define,
+                                       :admin_manually,
+                                       :admin_by_define,
+                                       :user_hash,
+                                       :invalid_user]
+    end
+  end
+
+  describe '#traits_for' do
+    it 'returns an array of trait names defined for the given factory' do
+      Factory.traits_for(:user_manually).should eq ['manager']
+    end
+  end
+
+  describe '#create!' do
+    context 'given invalid record' do
+      let(:factory_name) { :invalid_user }
+
+      it 'raises an error if validation failed' do
+        expect { Factory.create!(factory_name) }.to raise_error('Validation failed: {:required_attr=>["can\'t be blank"]}')
+      end
+    end
+
+    context 'given valid record' do
+      let(:factory_name) { :user }
+
+      it 'creates object' do
+        result = nil
+        expect { result = Factory.create!(factory_name) }.to_not raise_error
+        result.should be_saved
+      end
+    end
   end
 
   it "is alive" do
@@ -37,10 +74,10 @@
   end
 
   it "clears all instance variables when reset" do
-    Factory.some_instance_variable = true
-    Factory.some_instance_variable.should == true
+    Factory.instance_variable_set('@some_instance_variable', true)
+    Factory.instance_variable_get('@some_instance_variable').should be_true
     Factory.reset
-    Factory.some_instance_variable.should == nil
+    Factory.instance_variable_get('@some_instance_variable').should be_nil
   end
 
   it "can create items using the define helper or manually" do
@@ -79,7 +116,7 @@
   describe "debugger" do 
 
     it "raises an error if the factory produces an invalid object when enabled (rails only)" do
-      expect { Factory.debug(:user) }.to raise_error(
+      expect { Factory.debug(:user, required_attr: nil) }.to raise_error(
         'Oops, the User created by the Factory has the following errors: {:required_attr=>["can\'t be blank"]}'
       )
     end
@@ -147,7 +184,7 @@
   end
 
   it "returns nothing extra in the attributes" do
-    crank(:user_attrs).size.should == 5
+    crank(:user_attrs).size.should == 6
   end
 
   specify "attributes for works with factory methods using inherit" do

spec/linter_spec.rb

@@ -0,0 +1,38 @@
+require 'spec_helper'
+
+describe 'Factory.lint' do
+  it 'raises when a factory is invalid' do
+    error_message = <<-ERROR_MESSAGE.strip
+The following factories are invalid:
+
+* user_hash - undefined method `save!' for [:name, "Fred"]:Array (NoMethodError)
+* invalid_user - Validation failed: {:required_attr=>["can't be blank"]} (RuntimeError)
+    ERROR_MESSAGE
+
+    expect do
+      Factory.lint!
+    end.to raise_error Cranky::Linter::InvalidFactoryError, error_message
+  end
+
+  it 'does not raise when all factories are valid' do
+    expect { Factory.lint!(factory_names: [:admin_manually, :address]) }.not_to raise_error
+  end
+
+  describe "trait validation" do
+    context "enabled" do
+      it "raises if a trait produces an invalid object" do
+        error_message = <<-ERROR_MESSAGE.strip
+The following factories are invalid:
+
+* user+invalid - Validation failed: {:required_attr=>["can't be blank"]} (RuntimeError)
+* user_hash - undefined method `save!' for [:name, "Fred"]:Array (NoMethodError)
+* invalid_user - Validation failed: {:required_attr=>["can't be blank"]} (RuntimeError)
+        ERROR_MESSAGE
+
+        expect do
+          Factory.lint!(traits: true)
+        end.to raise_error Cranky::Linter::InvalidFactoryError, error_message
+      end
+    end
+  end
+end