convert should support any output format

app/processors/geo_concerns/processors/base_geo_processor.rb

@@ -1,4 +1,5 @@
 require 'mini_magick'
+require 'pathname'
 
 module GeoConcerns
   module Processors
@@ -34,26 +35,27 @@ def self.run_commands(in_path, out_path, method_queue, options)
         # @return [String] tempfile path
         def self.temp_path(path)
           time = (Time.now.to_f * 1000).to_i
-          "#{File.dirname(path)}/#{File.basename(path, File.extname(path))}_#{time}"
+          path = Pathname.new(path)
+          "#{path.dirname}/#{path.basename(path.extname)}_#{time}"
         end
 
-        # Uses imagemagick to resize an image and convert it to jpeg format.
+        # Uses imagemagick to resize an image and convert it to the output format.
         # Keeps the aspect ratio of the original image and adds padding to
-        # to the ouput image.
+        # to the output image. The file extension is the output format.
         # @param in_path [String] file input path
-        # @param out_path [String] processor output file path
+        # @param out_path [String] processor output file path.
         # @param options [Hash] creation options
+        # @option options [String] `:output_size` as "w h" or "wxh"
         def self.convert(in_path, out_path, options)
-          size = options[:output_size].tr(' ', 'x')
-          # byebug
           image = MiniMagick::Image.open(in_path)
-          image.format 'jpg'
           image.combine_options do |i|
+            size = options[:output_size].tr(' ', 'x')
             i.resize size
             i.background 'white'
             i.gravity 'center'
             i.extent size
           end
+          image.format Pathname.new(out_path).extname
           image.write(out_path)
         end
       end
@@ -89,7 +91,8 @@ def output_srid
       # Extracts the base file name (without extension) from the source file path.
       # @return [String] base file name for source
       def basename
-        File.basename(source_path, File.extname(source_path))
+        path = Pathname.new(source_path)
+        path.basename(path.extname)
       end
     end
   end

spec/processors/geo_concerns/processors/base_geo_processor_spec.rb

@@ -21,7 +21,9 @@ def source_path
   subject { TestProcessor.new }
 
   let(:directives) { { format: 'png', size: '200x400' } }
-  let(:output_file) { 'output/geo.png' }
+  let(:output_file_jpg) { 'output/geo.jpg' }
+  let(:output_file_png) { 'output/geo.png' }
+  let(:output_file) { output_file_png }
   let(:file_name) { 'files/geo.tif' }
   let(:options) { { output_size: '150 150' } }
 
@@ -43,11 +45,18 @@ def source_path
       allow(MiniMagick::Image).to receive(:open).and_return(image)
     end
 
-    it 'transforms the image and saves it as a jpeg' do
+    it 'transforms the image and saves it as a PNG' do
+      expect(image).to receive(:format).with('png')
+      expect(image).to receive(:combine_options)
+      expect(image).to receive(:write).with(output_file_png)
+      subject.class.convert(file_name, output_file_png, options)
+    end
+
+    it 'transforms the image and saves it as a JPG' do
       expect(image).to receive(:format).with('jpg')
       expect(image).to receive(:combine_options)
-      expect(image).to receive(:write).with(output_file)
-      subject.class.convert(file_name, output_file, options)
+      expect(image).to receive(:write).with(output_file_jpg)
+      subject.class.convert(file_name, output_file_jpg, options)
     end
   end