TODO formatter

spec/ameba/formatter/todo_formatter_spec.cr

@@ -0,0 +1,44 @@
+require "../../spec_helper"
+
+module Ameba
+  private def create_todo(formatter)
+    s = Source.new "a = 1"
+    s.error DummyRule.new, s.location(1, 2), "message"
+    formatter.finished [s]
+  end
+
+  describe Formatter::TODOFormatter do
+    file = IO::Memory.new
+    subject = Formatter::TODOFormatter.new IO::Memory.new, file
+
+    context "problems not reported" do
+      it "does not create todo" do
+        subject.finished [Source.new ""]
+        file.to_s.empty?.should be_true
+      end
+    end
+
+    context "problems reported" do
+      it "creates a todo with header" do
+        create_todo subject
+        file.to_s.should contain "# This configuration file was generated by"
+        file.to_s.should contain "Ameba version #{VERSION}"
+      end
+
+      it "creates a todo with rule name" do
+        create_todo subject
+        file.to_s.should contain "DummyRule"
+      end
+
+      it "creates a todo with problems count" do
+        create_todo subject
+        file.to_s.should contain "Problems found: 1"
+      end
+
+      it "creates a valid YAML document" do
+        create_todo subject
+        YAML.parse(file.to_s).should_not be_nil
+      end
+    end
+  end
+end

src/ameba/cli/cmd.cr

@@ -46,13 +46,11 @@ module Ameba::Cli
   def run_ameba(opts)
     config = Ameba::Config.load opts.config
     config.files = opts.files
-    config.formatter = Ameba::Formatter::BaseFormatter.new if opts.silent
 
+    configure_formatter(config, opts)
     configure_rules(config, opts)
 
-    runner = Ameba.run(config)
-    generate_config_file(config, runner, opts) if opts.generate
-    exit 1 unless runner.success?
+    exit 1 unless Ameba.run(config).success?
   rescue e
     puts "Error: #{e.message}"
     exit 255
@@ -71,14 +69,14 @@ module Ameba::Cli
     end
   end
 
-  private def generate_config_file(config, runner, opts)
-    failed_rules =
-      runner.sources
-            .map { |s| s.errors.map &.rule.name }
-            .flatten
-            .uniq!
-    failed_rules.each { |rule| config.update_rule rule, enabled: false }
-    File.write(opts.config, config.to_yaml)
+  private def configure_formatter(config, opts)
+    if opts.silent
+      config.formatter = Ameba::Formatter::BaseFormatter.new
+    elsif opts.generate
+      config.formatter = Ameba::Formatter::TODOFormatter.new
+    else
+      config.formatter = Ameba::Formatter::DotFormatter.new
+    end
   end
 
   private def print_version

src/ameba/config.cr

@@ -20,7 +20,7 @@ class Ameba::Config
   # Creates a new instance of `Ameba::Config` based on YAML parameters.
   #
   # `Config.load` uses this constructor to instantiate new config by YAML file.
-  protected def initialize(@config : Hash(YAML::Type, YAML::Type))
+  protected def initialize(@config : YAML::Any)
     @rules = Rule.rules.map &.new(config)
   end
 
@@ -31,9 +31,9 @@ class Ameba::Config
   # ```
   #
   def self.load(path = PATH)
-    content = File.exists?(path) ? File.read path : "{}"
-    Config.new YAML.parse(content).as_h
-  rescue e
+    content = File.exists?(path) ? File.read path : ""
+    Config.new YAML.parse(content)
+  rescue
     raise "Config file is invalid"
   end
 
@@ -80,15 +80,6 @@ class Ameba::Config
     @rules[index] = rule
   end
 
-  def to_yaml(yaml : YAML::Builder)
-    yaml.mapping do
-      rules.each do |rule|
-        rule.name.to_yaml(yaml)
-        rule.to_yaml(yaml)
-      end
-    end
-  end
-
   private def default_files
     Dir["**/*.cr"].reject(&.starts_with? "lib/")
   end
@@ -158,8 +149,10 @@ class Ameba::Config
         properties {}
 
         def self.new(config = nil)
-          yaml = config.try &.[class_name]?.try &.to_yaml || "{}"
-          from_yaml yaml
+          if (raw = config.try &.raw).is_a? Hash
+            yaml = raw[class_name]?.try &.to_yaml
+          end
+          from_yaml yaml || "{}"
         end
       end
     end

src/ameba/formatter/dot_formatter.cr

@@ -21,7 +21,7 @@ module Ameba::Formatter
     # Reports a message when inspection is finished.
     def finished(sources)
       output << "\n\n"
-      failed_sources = sources.reject { |s| s.valid? }
+      failed_sources = sources.reject &.valid?
 
       failed_sources.each do |source|
         source.errors.each do |error|

src/ameba/formatter/todo_formatter.cr

@@ -0,0 +1,59 @@
+module Ameba::Formatter
+  # A formatter that creates a todo config.
+  # Basically, it takes all errors reported and disables corresponding rules
+  # or excludes failed sources from these rules.
+  class TODOFormatter < DotFormatter
+    @io : IO::FileDescriptor | IO::Memory
+
+    def initialize(@output = STDOUT, @io = File.new(Config::PATH, mode: "w"))
+    end
+
+    def finished(sources)
+      super
+      errors = sources.map(&.errors).flatten
+      generate_todo_config errors if errors.any?
+      if (io = @io).is_a?(File)
+        @output << "Created #{io.path}\n"
+      end
+    end
+
+    private def generate_todo_config(errors)
+      @io << header
+      rule_errors_map(errors).each do |rule, rule_errors|
+        @io << "\n# Problems found: #{rule_errors.size}"
+        @io << rule_todo(rule, rule_errors).gsub("---", "")
+      end
+    ensure
+      @io.flush
+    end
+
+    private def rule_errors_map(errors)
+      Hash(Rule::Base, Array(Source::Error)).new.tap do |h|
+        errors.each do |error|
+          h[error.rule] ||= Array(Source::Error).new
+          h[error.rule] << error
+        end
+      end
+    end
+
+    private def header
+      <<-HEADER
+        # This configuration file was generated by `ameba --gen-config`
+        # on #{Time.now} using Ameba version #{VERSION}.
+        # The point is for the user to remove these configuration records
+        # one by one as the reported problems are removed from the code base.
+
+        HEADER
+    end
+
+    private def rule_todo(rule, errors)
+      rule.enabled = false
+      YAML.build do |yaml|
+        yaml.mapping do
+          rule.name.to_yaml(yaml)
+          rule.to_yaml(yaml)
+        end
+      end
+    end
+  end
+end