Add DisabledFormatter to trace disabled lines

spec/ameba/formatter/disabled_formatter_spec.cr

@@ -0,0 +1,41 @@
+require "../../spec_helper"
+
+module Ameba::Formatter
+  describe DisabledFormatter do
+    output = IO::Memory.new
+    subject = DisabledFormatter.new output
+
+    describe "#finished" do
+      it "writes a final message" do
+        subject.finished [Source.new ""]
+        output.to_s.should contain "Disabled rules using inline directives:"
+      end
+
+      it "writes disabled rules if any" do
+        Colorize.enabled = false
+
+        path = "source.cr"
+        s = Source.new("", path).tap do |s|
+          s.error(ErrorRule.new, 1, 2, "ErrorRule", :disabled)
+          s.error(NamedRule.new, 2, 2, "NamedRule", :disabled)
+        end
+        subject.finished [s]
+        log = output.to_s
+        log.should contain "#{path}:1 #{ErrorRule.name}"
+        log.should contain "#{path}:2 #{NamedRule.name}"
+      ensure
+        output.clear
+        Colorize.enabled = true
+      end
+
+      it "does not write not-disabled rules" do
+        s = Source.new("", "source.cr").tap do |s|
+          s.error(ErrorRule.new, 1, 2, "ErrorRule")
+          s.error(NamedRule.new, 2, 2, "NamedRule", :disabled)
+        end
+        subject.finished [s]
+        output.to_s.should_not contain ErrorRule.name
+      end
+    end
+  end
+end

src/ameba/config.cr

@@ -17,6 +17,7 @@ class Ameba::Config
     todo:     Formatter::TODOFormatter,
     flycheck: Formatter::FlycheckFormatter,
     silent:   Formatter::BaseFormatter,
+    disabled: Formatter::DisabledFormatter,
   }
 
   PATH = ".ameba.yml"

src/ameba/formatter/disabled_formatter.cr

@@ -0,0 +1,17 @@
+module Ameba::Formatter
+  # A formatter that shows all disabled line using inline directives.
+  class DisabledFormatter < BaseFormatter
+    def finished(sources)
+      output << "Disabled rules using inline directives: \n\n"
+
+      sources.each do |source|
+        source.errors.select(&.disabled?).each do |e|
+          if loc = e.location
+            output << "#{source.path}:#{loc.line_number}".colorize(:cyan)
+            output << " #{e.rule.name}\n"
+          end
+        end
+      end
+    end
+  end
+end

src/ameba/inline_comments.cr

@@ -10,7 +10,7 @@ module Ameba
     #   1. The line of the location ends with a comment directive.
     #   2. The line above the location is a comment directive.
     #
-    # For example, here is two examples of disabled location:
+    # For example, here are two examples of disabled location:
     #
     # ```
     # # ameba:disable LargeNumbers

src/ameba/source.cr

@@ -7,7 +7,7 @@ module Ameba
     # Represents an error caught by Ameba.
     #
     # Each error has the rule that created this error,
-    # location of the issue and a message.
+    # location of the issue, message and status.
     record Error,
       rule : Rule::Base,
       location : Crystal::Location?,
@@ -43,7 +43,7 @@ module Ameba
     def initialize(@code : String, @path = "")
     end
 
-    # Adds new error to the list of errors.
+    # Adds a new error to the list of errors.
     #
     # ```
     # source.error rule, location, "Line too long"
@@ -54,7 +54,7 @@ module Ameba
       errors << Error.new rule, location, message, status
     end
 
-    # Adds new error to the list of errors using line and column number.
+    # Adds a new error to the list of errors using line and column number.
     #
     # ```
     # source.error rule, line_number, column_number, "Bad code"