Support specification of content type in attaches_file()

lib/webrat/core/field.rb

@@ -240,11 +240,19 @@ def default_value
 
   class FileField < Field
 
+    attr_accessor :content_type
+
+    def set(value, content_type = nil)
+      super(value)
+      @content_type = content_type
+    end
+
     def to_param
       if @value.nil?
         super
       else
-        replace_param_value(super, @value, ActionController::TestUploadedFile.new(@value))
+        file = content_type ? ActionController::TestUploadedFile.new(@value, content_type) : ActionController::TestUploadedFile.new(@value)
+        replace_param_value(super, @value, file)
       end
     end
 

lib/webrat/core/page.rb

@@ -91,13 +91,14 @@ def selects(option_text, options = {})
 
     # Verifies that an input file field exists on the current page and sets
     # its value to the given +file+, so that the file will be uploaded
-    # along with the form.
+    # along with the form. An optional <tt>content_type</tt> may be given.
     #
     # Example:
-    #   attaches_file "Photo", "/path/to/the/photo.jpg"
-    def attaches_file(id_or_name_or_label, path)
+    #   attaches_file "Resume", "/path/to/the/resume.txt"
+    #   attaches_file "Photo", "/path/to/the/image.png", "image/png"
+    def attaches_file(id_or_name_or_label, path, content_type = nil)
       field = find_field(id_or_name_or_label, FileField)
-      field.set(path)
+      field.set(path, content_type)
     end
 
     # Saves the page out to RAILS_ROOT/tmp/ and opens it in the default

spec/api/attaches_file_spec.rb

@@ -56,4 +56,17 @@
     @session.attaches_file "Spreadsheet", @filename
     @session.clicks_button
   end
+
+  it "should allow the content type to be specified" do
+    @session.response_body = <<-EOS
+      <form method="post" action="/widgets">
+        <label for="person_picture">Picture</label>
+        <input type="file" id="person_picture" name="person[picture]" />
+        <input type="submit" />
+      </form>
+    EOS
+    ActionController::TestUploadedFile.expects(:new).with(@filename, "image/png").returns(@uploaded_file)
+    @session.attaches_file "Picture", @filename, "image/png"
+    @session.clicks_button
+  end
 end