Add ability to run summaries

README.md

@@ -27,7 +27,7 @@ rake eslint:print_config[true]
 ```
 
 You can also retrieve the current eslint.json by visiting `/eslint/eslint.json`
-in your browser. To force retrieval of the default conguration, use
+in your browser. To force retrieval of the default configuration, use
 `/eslint/eslint.json?force_default=true`.
 
 ## Usage
@@ -48,7 +48,9 @@ Or you can run it on a single file. This will analyze `application.js`:
 rake eslint:run
 ```
 
-Or, you can supply a filename to the task, using several different formats, and it will lint just that file. For example, to analyze `app/assets/javascripts/components/utilities.js`, you can run any of the following:
+Or, you can supply a filename to the task, using several different formats, 
+and it will lint just that file. For example, to analyze 
+`app/assets/javascripts/components/utilities.js`, you can run any of the following:
 
 ```sh
 rake eslint:run[components/utilities]
@@ -57,6 +59,40 @@ rake eslint:run[app/assets/javascripts/components/utilities]
 rake eslint:run[app/assets/javascripts/components/utilities.js]
 ```
 
+###### Summaries
+
+This will analyze all of the javascript files in the project and return a 
+summary of warnings based on the `group_by` filter parameter:
+
+```sh
+rake eslint:summary[group_by]
+```
+
+Available `group_by` filters: 
+
+- `filename` - displays number of warnings occurred per file
+
+- `warning` - displays number of warnings occurred per assets
+
+
+Or you can get a summary of the warnings on a single file. This will show 
+the summary for `application.js`:
+
+```sh
+rake eslint:file_summary
+```
+
+Or, you can supply a filename to the task, using several different formats, 
+and it will lint just that file. For example, to analyze 
+`app/assets/javascripts/components/utilities.js`, you can run any of the following:
+
+```sh
+rake eslint:file_summary[components/utilities]
+rake eslint:file_summary[components/utilities.js]
+rake eslint:file_summary[app/assets/javascripts/components/utilities]
+rake eslint:file_summary[app/assets/javascripts/components/utilities.js]
+```
+
 ### Web interface
 
 On non-production environments, visit these URLs on your application:

lib/eslint-rails/runner.rb

@@ -5,6 +5,7 @@ class Runner
     include ActionView::Helpers::JavaScriptHelper
 
     JAVASCRIPT_EXTENSIONS = %w(.js .jsx)
+    SUMMARY_FILTERS = %w(filename warning)
 
     def initialize(file)
       @file = normalize_infile(file)
@@ -20,6 +21,30 @@ def run
       warnings.flatten
     end
 
+    def summary(group_by: 'filename')
+      raise "Unknown filter. Accepted values: #{SUMMARY_FILTERS.join(', ')}" unless SUMMARY_FILTERS.include?(group_by)
+      results = []
+      assets.map do |asset|
+        file_content = asset.read
+        if group_by == 'filename'
+          results << { item: asset.relative_path_from(Pathname.new(Dir.pwd)), count: warning_hashes(file_content).count }
+        else
+          file_warnings_by_rule = warning_hashes(file_content).group_by { |w| w['ruleId'] }.values
+          file_warnings_by_rule.map do |a|
+            # When rule ID is nil set type to +UnknownError+
+            warning_type = a.first['ruleId'] ? "#{a.first['nodeType']}/#{a.first['ruleId']}" : 'UnexpectedError'
+            warning = results.find { |r| r[:item] == warning_type }
+            if warning
+              warning[:count] += a.size
+            else
+              results << { item: warning_type, count: a.size }
+            end
+          end
+        end
+      end
+      results.sort_by { |r| -r[:count] }
+    end
+
     private
 
     def normalize_infile(file)

lib/eslint-rails/text_formatter.rb

@@ -30,10 +30,23 @@ def format
           end
         puts colorized_message
       end
-
       puts "#{@warnings.size} warning(s) found."
     end
 
+    def format_summary
+      max_count_length = max_length_of_attribute(:count)
+      @warnings.each do |warning|
+        message = [
+            warning[:count].to_s.ljust(max_count_length + 1),
+            warning[:item],
+        ].join(' ')
+        puts message
+      end
+      total = @warnings.inject(0) {|sum, hash| sum + hash[:count]}
+      puts '--'
+      puts "#{total} warning(s) found."
+    end
+
     private
 
     def max_length_of_attribute(attr_key)

lib/tasks/eslint.rake

@@ -3,15 +3,23 @@ ENV['EXECJS_RUNTIME'] = 'RubyRacer'
 require 'eslint-rails'
 
 namespace :eslint do
-  def run_and_print_results(file)
-    warnings = ESLintRails::Runner.new(file).run
+  def run_and_print_results(file, group_by = nil)
+    if group_by
+      warnings = ESLintRails::Runner.new(file).summary(group_by: group_by)
+    else
+      warnings = ESLintRails::Runner.new(file).run
+    end
 
     if warnings.empty?
       puts 'All good! :)'.green
       exit 0
     else
       formatter = ESLintRails::TextFormatter.new(warnings)
-      formatter.format
+      if group_by
+        formatter.format_summary
+      else
+        formatter.format
+      end
       exit 1
     end
   end
@@ -26,6 +34,16 @@ namespace :eslint do
     run_and_print_results(nil) # Run all
   end
 
+  desc 'Run ESLint against all project javascript files and report summary based on filter'
+  task :summary, [:group_by] => :environment do |_, args|
+    run_and_print_results(nil, args[:group_by])
+  end
+
+  desc %{Run ESLint against the specified JavaScript file and report a summary of warnings (default is 'application')}
+  task :file_summary, [:filename] => :environment do |_, args|
+    run_and_print_results(args[:filename] || 'application', 'warning')
+  end
+
   desc 'Print the current configuration file (Uses local config/eslint.json if it exists; uses default config/eslint.json if it does not; optionally force default by passing a parameter)'
   task :print_config, [:force_default] => :environment do |_, args|
     puts ESLintRails::Config.read(force_default: args[:force_default])