It works

README.md

@@ -33,6 +33,21 @@ require "ameba"
 Ameba.run
 ```
 
+```sh
+Inspecting 7 files.
+
+
+..F...F
+
+7 inspected, 2 failures.
+
+src/ameba/formatter.cr:47
+Ameba::Rule::LineLength: Line too long [122]
+
+src/ameba.cr:18
+Ameba::Rule::LineLength: Line too long [81]
+```
+
 ## Contributing
 
 1. Fork it ( https://github.com/veelenga/ameba/fork )

src/ameba.cr

@@ -13,7 +13,7 @@ module Ameba
   end
 
   def run(files, formatter : Formatter)
-    sources = files.map { |path| Source.new(File.read path) }
+    sources = files.map { |path| Source.new(path) }
 
     reporter = Reporter.new formatter
     reporter.start sources

src/ameba/formatter.cr

@@ -13,6 +13,7 @@ module Ameba
 
     def start(sources)
       puts formatter.before sources
+      puts "\n\n"
     end
 
     def report(source)
@@ -20,7 +21,7 @@ module Ameba
     end
 
     def finish(sources)
-      puts
+      puts "\n\n"
       puts formatter.after sources
     end
   end
@@ -39,7 +40,20 @@ module Ameba
     end
 
     def after(sources)
-      "Done!"
+      String.build do |mes|
+        failures = sources.select { |s| s.errors.any? }
+        l = failures.map { |f| f.errors.size }.sum
+
+        mes << "#{sources.size} inspected, #{l} failure#{"s" if l != 1}.\n\n"
+
+        failures.each do |failure|
+          failure.errors.each do |error|
+            mes << "#{failure.path}:#{error.pos}"
+            mes << "\n"
+            mes << "#{error.rule}: #{error.message}\n\n"
+          end
+        end
+      end
     end
   end
 end

src/ameba/rule/line_length.cr

@@ -1,8 +1,8 @@
 struct Ameba::Rule::LineLength
   def test(source)
-    source.lines.each do |line|
+    source.lines.each_with_index do |line, index|
       if line.size > 79
-        source.errors << "Line too long"
+        source.error self, index + 1, "Line too long [#{line.size}]"
       end
     end
   end

src/ameba/source.cr

@@ -1,10 +1,20 @@
 module Ameba
   class Source
-    getter lines : Array(String)
-    getter errors = [] of String
+    record Error,
+      rule : String,
+      pos : Int32,
+      message : String
 
-    def initialize(content : String)
-      @lines = content.split "\n"
+    getter lines : Array(String)
+    getter errors = [] of Error
+    getter path : String
+
+    def initialize(@path : String)
+      @lines = File.read_lines(@path)
+    end
+
+    def error(rule, line_number : Int32, message : String)
+      errors << Error.new rule.class.name, line_number, message
     end
   end
 end