Simple reporter

src/ameba.cr

@@ -8,14 +8,20 @@ module Ameba
     Rule::LineLength,
   ]
 
-  def run
-    run Dir["**/*.cr"]
+  def run(formatter = DotFormatter.new)
+    run Dir["**/*.cr"], formatter
   end
 
-  def run(files)
-    files.each do |path|
-      catch Source.new(File.read path)
+  def run(files, formatter : Formatter)
+    sources = files.map { |path| Source.new(File.read path) }
+
+    reporter = Reporter.new formatter
+    reporter.start sources
+    sources.each do |source|
+      catch(source)
+      reporter.report source
     end
+    reporter.try &.finish sources
   end
 
   def catch(source : Source)

src/ameba/formatter.cr

@@ -0,0 +1,45 @@
+module Ameba
+  abstract class Formatter
+    abstract def before(sources)
+    abstract def format(source : Source)
+    abstract def after(sources)
+  end
+
+  class Reporter
+    property formatter : Formatter
+
+    def initialize(@formatter : Formatter)
+    end
+
+    def start(sources)
+      puts formatter.before sources
+    end
+
+    def report(source)
+      print formatter.format source
+    end
+
+    def finish(sources)
+      puts
+      puts formatter.after sources
+    end
+  end
+
+  class DotFormatter < Formatter
+    def before(sources)
+      if (len = sources.size) == 1
+        "Inspecting 1 file."
+      else
+        "Inspecting #{len} files."
+      end
+    end
+
+    def format(source : Source)
+      source.errors.size == 0 ? "." : "F"
+    end
+
+    def after(sources)
+      "Done!"
+    end
+  end
+end