checking bin versions, closes #33

lib/image_optim/bin_resolver.rb

@@ -3,7 +3,20 @@
 
 class ImageOptim
   class BinNotFoundError < StandardError; end
+  class BadBinVersion < StandardError; end
+
   class BinResolver
+    class Bin
+      attr_reader :name, :version
+      def initialize(name, version)
+        @name, @version = name, version
+      end
+
+      def to_s
+        "#{@name} #{@version || '-'}"
+      end
+    end
+
     attr_reader :dir
     def initialize
       @bins = {}
@@ -12,10 +25,16 @@ def initialize
 
     def resolve!(name)
       name = name.to_sym
+
       resolving(name) do
-        @bins[name] = resolve?(name)
+        @bins[name] = resolve?(name) && Bin.new(name, version(name))
+      end
+
+      if @bins[name]
+        check!(@bins[name])
+      else
+        raise BinNotFoundError, "`#{name}` not found"
       end
-      @bins[name] or raise BinNotFoundError, "`#{name}` not found"
     end
 
     VENDOR_PATH = File.expand_path('../../../vendor', __FILE__)
@@ -52,6 +71,34 @@ def accessible?(name)
       capture_output("which #{name.to_s.shellescape}") != ''
     end
 
+    def version(name)
+      case name.to_sym
+      when :advpng, :gifsicle, :jpegoptim, :optipng
+        capture_output("#{name} --version")[/\d+(\.\d+){1,}/]
+      when :svgo
+        capture_output("#{name} --version 2>&1")[/\d+(\.\d+){1,}/]
+      when :jhead
+        capture_output("#{name} -V")[/\d+(\.\d+){1,}/]
+      when :jpegtran
+        capture_output("#{name} -v - 2>&1")[/version (\d+\S*)/, 1]
+      when :pngcrush
+        capture_output("#{name} -version 2>&1")[/\d+(\.\d+){1,}/]
+      when :pngout
+        date_str = capture_output("#{name} 2>&1")[/[A-Z][a-z]{2} (?: |\d)\d \d{4}/]
+        Date.parse(date_str).strftime('%Y%m%d')
+      end
+    end
+
+    def check!(bin)
+      case bin.name
+      when :pngcrush
+        case bin.version
+        when '1.7.60'..'1.7.65'
+          raise BadBinVersion, "`#{bin}` is known to produce broken pngs"
+        end
+      end
+    end
+
     def capture_output(command)
       `env PATH=#{env_path.shellescape} #{command}`
     end

spec/image_optim/bin_resolver_spec.rb

@@ -106,4 +106,20 @@ def with_env(key, value)
       end.each(&:join)
     end
   end
+
+  it "should raise on detection of problematic version" do
+    with_env 'PNGCRUSH_BIN', nil do
+      resolver = ImageOptim::BinResolver.new
+      resolver.should_receive(:accessible?).with(:pngcrush).once.and_return(true)
+      resolver.should_receive(:version).with(:pngcrush).once.and_return('1.7.60')
+      FSPath.should_not_receive(:temp_dir)
+
+      5.times do
+        expect do
+          resolver.resolve!(:pngcrush)
+        end.to raise_error ImageOptim::BadBinVersion
+      end
+      resolver.env_path.should == "#{ENV['PATH']}:#{ImageOptim::BinResolver::VENDOR_PATH}"
+    end
+  end
 end