Change parse_http to follow http redirect

format_parser.gemspec

@@ -34,6 +34,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency 'exifr', '~> 1', '>= 1.3.8'
   spec.add_dependency 'id3tag', '~> 0.14'
   spec.add_dependency 'faraday', '~> 0.13'
+  spec.add_dependency 'faraday_middleware', '~> 0.14'
   spec.add_dependency 'measurometer', '~> 1'
 
   spec.add_development_dependency 'rspec', '~> 3.0'

lib/remote_io.rb

@@ -26,6 +26,7 @@ class InvalidRequest < UpstreamError
   # @param uri[URI, String] the remote URL to obtain
   def initialize(uri)
     require 'faraday'
+    require 'faraday_middleware/response/follow_redirects'
     @uri = uri
     @pos = 0
     @remote_size = false
@@ -78,7 +79,11 @@ def request_range(range)
     # We use a GET and not a HEAD request followed by a GET because
     # S3 does not allow HEAD requests if you only presigned your URL for GETs, so we
     # combine the first GET of a segment and retrieving the size of the resource
-    response = Faraday.get(@uri, nil, range: 'bytes=%d-%d' % [range.begin, range.end])
+    conn = Faraday.new do |faraday|
+      faraday.use FaradayMiddleware::FollowRedirects
+      faraday.adapter Faraday.default_adapter
+    end
+    response = conn.get(@uri, nil, range: 'bytes=%d-%d' % [range.begin, range.end])
 
     case response.status
     when 200, 206

spec/remote_fetching_spec.rb

@@ -15,6 +15,10 @@
     }
     @server = WEBrick::HTTPServer.new(options)
     @server.mount '/', WEBrick::HTTPServlet::FileHandler, fixtures_dir
+    @server.mount_proc '/redirect' do |req,res|
+      res.status = 302
+      res.header['Location'] = req.path.sub("/redirect","")
+    end
     trap('INT') { @server.stop }
     @server_thread = Thread.new { @server.start }
   end
@@ -91,6 +95,13 @@
     end
   end
 
+  context 'when the server respond with a redirect' do
+    it 'follows the redirect' do
+      file_information = FormatParser.parse_http('http://localhost:9399/redirect/TIFF/test.tif')
+      expect(file_information.format).to eq(:tif)
+    end
+  end
+
   after(:all) do
     @server.stop
     @server_thread.join(0.5)