Merge pull request #59 from curationexperts/conversion_error

Raise a custom error when conversion fails

app/services/riiif/command_runner.rb

@@ -16,7 +16,7 @@ def execute(command)
         stdout.close
         err = stderr.read
         stderr.close
-        raise "Unable to execute command \"#{command}\"\n#{err}" unless wait_thr.value.success?
+        raise ConversionError, "Unable to execute command \"#{command}\"\n#{err}" unless wait_thr.value.success?
       end
       out
     end

lib/riiif.rb

@@ -1,6 +1,5 @@
 require 'riiif/version'
 require 'riiif/engine'
-
 module Riiif
   extend ActiveSupport::Autoload
   autoload :Image
@@ -19,6 +18,8 @@ def initialize(orig = nil)
       @original_exception = orig
     end
   end
+  # This error is raised when Riiif can't convert an image
+  class ConversionError < Error; end
 
   Transformation = Struct.new(:crop, :size, :quality, :rotation, :format)
   ImageInformation = Struct.new(:width, :height)