diff --git a/.gitignore b/.gitignore
index 6b90aed9bf..d9073f40c3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -89,7 +89,6 @@ Gemfile.lock
 
 # Local Gemfile for developing without sharing dependencies
 .gemfile
-*.txt
 
 *.orig
 
diff --git a/resources/app/models/refinery/resource.rb b/resources/app/models/refinery/resource.rb
index 05defeaf8e..5882d6e122 100644
--- a/resources/app/models/refinery/resource.rb
+++ b/resources/app/models/refinery/resource.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require 'dragonfly'
 
 module Refinery
@@ -7,14 +9,18 @@ class Resource < Refinery::Core::BaseModel
     extend Mobility
     translates :resource_title
 
-    dragonfly_accessor :file, :app => :refinery_resources
+    dragonfly_accessor :file, app: :refinery_resources
 
-    validates :file, :presence => true
+    validates :file, presence: true
     validates_with FileSizeValidator
+    validates_property :mime_type,
+                       of: :file,
+                       in: ::Refinery::Resources.whitelisted_mime_types,
+                       message: :incorrect_format
 
-    delegate :ext, :size, :mime_type, :url, :to => :file
+    delegate :ext, :size, :mime_type, :url, to: :file
 
-    before_destroy :cached_mime_type, :prepend => true
+    before_destroy :cached_mime_type, prepend: true
 
     def cached_mime_type
       @cached_mime_type ||= mime_type
@@ -22,18 +28,18 @@ def cached_mime_type
 
     # used for searching
     def type_of_content
-      cached_mime_type.split("/").join(" ")
+      cached_mime_type.split('/').join(' ')
     end
 
     # Returns a titleized version of the filename
     # my_file.pdf returns My File
     def title
-      resource_title.presence || CGI::unescape(file_name.to_s).gsub(/\.\w+$/, '').titleize
+      resource_title.presence || CGI.unescape(file_name.to_s).gsub(/\.\w+$/, '').titleize
     end
 
     def update_index
-      return if self.aai_config.disable_auto_indexing
-      copy = self.dup.tap{ |r| r.file_uid = r.file_uid_was}
+      return if aai_config.disable_auto_indexing
+      copy = dup.tap { |r| r.file_uid = r.file_uid_was }
       self.class.index_remove(copy)
       self.class.index_add(self)
     end
@@ -47,9 +53,9 @@ def per_page(dialog = false)
       def create_resources(params)
         resources = []
 
-        if params.present? and params[:file].is_a?(Array)
+        if params.present? && params[:file].is_a?(Array)
           params[:file].each do |resource|
-            resources << create({:file => resource}.merge(params.except(:file).to_h))
+            resources << create({ file: resource }.merge(params.except(:file).to_h))
           end
         else
           resources << create(params)
diff --git a/resources/config/locales/en.yml b/resources/config/locales/en.yml
index b6689991f1..904ec0854b 100644
--- a/resources/config/locales/en.yml
+++ b/resources/config/locales/en.yml
@@ -36,4 +36,6 @@ en:
       models:
         refinery/resource:
           blank: You must specify file for upload
-          too_big: File should be smaller than %{size} bytes in size
+          incorrect_format: "File type is not allowed. Your file must be a MP4, MPEG, WMV, AVI, WAV,
+          GIF, JPEG, PNG, SVG, TIFF, PSD, CSV, PDF, TXT, RAR, ZIP, XLS, PPT or a DOC"
+          too_big: File should be smaller than %{size} bytes in size
\ No newline at end of file
diff --git a/resources/config/locales/fr.yml b/resources/config/locales/fr.yml
index 3524b3ae52..064847f643 100644
--- a/resources/config/locales/fr.yml
+++ b/resources/config/locales/fr.yml
@@ -36,4 +36,6 @@ fr:
       models:
         refinery/resource:
           blank: Vous devez spécifier un fichier à télécharger
-          too_big: Le poids maximal des fichiers est de %{size} megaoctets
+          incorrect_format: "Type de fichier non autorisé. Votre fichier doit être un MP4, MPEG, WMV, AVI, WAV,
+          GIF, JPEG, PNG, SVG, TIFF, PSD, CSV, PDF, TXT, RAR, ZIP, XLS, PPT ou un DOC"
+          too_big: Le poids maximal des fichiers est de %{size} megaoctets
\ No newline at end of file
diff --git a/resources/lib/generators/refinery/resources/templates/config/initializers/refinery/resources.rb.erb b/resources/lib/generators/refinery/resources/templates/config/initializers/refinery/resources.rb.erb
index 13e5ab74c8..ec526170d6 100644
--- a/resources/lib/generators/refinery/resources/templates/config/initializers/refinery/resources.rb.erb
+++ b/resources/lib/generators/refinery/resources/templates/config/initializers/refinery/resources.rb.erb
@@ -9,6 +9,9 @@ Refinery::Resources.configure do |config|
   # Configure how many resources per page should be displayed in the list of resources in the admin area
   # config.pages_per_admin_index = <%= Refinery::Resources.pages_per_admin_index.inspect %>
 
+  # Configure white-listed mime types for validation
+  # config.whitelisted_mime_types = <%= Refinery::Resources.whitelisted_mime_types.inspect %>
+
   # Configure Dragonfly.
   # Refer to config/initializers/refinery/dragonfly.rb for the full list of dragonfly configurations which can be used.
   # This includes all dragonfly config for Dragonfly v 1.1.1
diff --git a/resources/lib/refinery/resources/configuration.rb b/resources/lib/refinery/resources/configuration.rb
index eb1c15390d..5f0f8d0419 100644
--- a/resources/lib/refinery/resources/configuration.rb
+++ b/resources/lib/refinery/resources/configuration.rb
@@ -1,10 +1,12 @@
+# frozen_string_literal: true
+
 module Refinery
   module Resources
-
     extend Refinery::Dragonfly::ExtensionConfiguration
     include ActiveSupport::Configurable
 
-    config_accessor :max_file_size, :pages_per_dialog, :pages_per_admin_index, :content_disposition
+    config_accessor :max_file_size, :pages_per_dialog, :pages_per_admin_index,
+                    :content_disposition, :whitelisted_mime_types
 
     self.content_disposition = :attachment
     self.max_file_size = 52_428_800
@@ -13,6 +15,40 @@ module Resources
 
     self.dragonfly_name = :refinery_resources
 
-  end
-end
+    self.whitelisted_mime_types = %w[
+      audio/mp4
+      audio/mpeg
+      audio/wav
+      audio/x-wav
+
+      image/gif
+      image/jpeg
+      image/png
+      image/svg+xml
+      image/tiff
+      image/x-psd
+
+      video/mp4
+      video/mpeg
+      video/quicktime
+      video/x-msvideo
+      video/x-ms-wmv
 
+      text/csv
+      text/plain
+
+      application/pdf
+      application/rtf
+      application/x-rar
+      application/zip
+
+      application/vnd.ms-excel
+      application/vnd.ms-powerpoint
+      application/vnd.msword
+
+      application/vnd.openxmlformats-officedocument.presentationml.presentation
+      application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
+      application/vnd.openxmlformats-officedocument.wordprocessingml.document
+    ]
+  end
+end
\ No newline at end of file
diff --git a/resources/spec/factories/resource.rb b/resources/spec/factories/resource.rb
index 24c0421533..5518ed66e4 100644
--- a/resources/spec/factories/resource.rb
+++ b/resources/spec/factories/resource.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 FactoryBot.define do
-  factory :resource, :class => Refinery::Resource do
-    file Refinery.roots('refinery/resources').join("spec/fixtures/refinery_is_awesome.txt")
+  factory :resource, class: Refinery::Resource do
+    file Refinery.roots('refinery/resources').join('spec/fixtures/cape-town-tide-table.pdf')
   end
 end
diff --git a/resources/spec/features/refinery/admin/resources_spec.rb b/resources/spec/features/refinery/admin/resources_spec.rb
index 1e31548163..5dc96092cd 100644
--- a/resources/spec/features/refinery/admin/resources_spec.rb
+++ b/resources/spec/features/refinery/admin/resources_spec.rb
@@ -1,116 +1,135 @@
-# Encoding: UTF-8
-require "spec_helper"
+# frozen_string_literal: true
+
+require 'spec_helper'
 
 module Refinery
   module Admin
-    describe "Resources", :type => :feature do
+    describe 'Resources', type: :feature do
       refinery_login
 
-      context "when no files" do
-        it "invites to upload file" do
+      context 'when no files' do
+        it 'invites to upload file' do
           visit refinery.admin_resources_path
-          expect(page).to have_content(%q{There are no files yet. Click "Upload new file" to add your first file.})
+          expect(page).to have_content('There are no files yet. Click "Upload new file" to add your first file.')
         end
       end
 
-      it "shows upload file link" do
+      it 'shows upload file link' do
         visit refinery.admin_resources_path
-        expect(page).to have_content("Upload new file")
-        expect(page).to have_selector("a[href*='/refinery/resources/new']")
+        expect(page).to have_content('Upload new file')
+        expect(page).to have_selector('a[href*="/refinery/resources/new"]')
       end
 
-      context "new/create" do
-        it "uploads file", :js => true do
-          visit refinery.admin_resources_path
-          find('a', text: 'Upload new file').click
+      context 'new/create' do
+        let(:uploading_a_file) do
+          lambda do
+            visit refinery.admin_resources_path
+            find('a', text: 'Upload new file').click
 
-          expect(page).to have_selector 'iframe#dialog_iframe'
+            expect(page).to have_selector 'iframe#dialog_iframe'
 
-          page.within_frame('dialog_iframe') do
-            attach_file "resource_file", Refinery.roots('refinery/resources').
-                                                  join("spec/fixtures/refinery_is_awesome.txt")
-            click_button ::I18n.t('save', :scope => 'refinery.admin.form_actions')
+            page.within_frame('dialog_iframe') do
+              attach_file 'resource_file', file_path
+              click_button ::I18n.t('save', scope: 'refinery.admin.form_actions')
+            end
           end
+        end
 
-          expect(page).to have_content("Refinery Is Awesome")
-          expect(Refinery::Resource.count).to eq(1)
+        context 'when the file mime_type is acceptable' do
+          let(:file_path) { Refinery.roots('refinery/resources').join('spec/fixtures/cape-town-tide-table.pdf') }
+
+          it 'the file is uploaded', js: true do
+            expect(uploading_a_file).to change(Refinery::Resource, :count).by(1)
+          end
         end
 
-        describe "max file size" do
+        context 'when the file mime_type is not acceptable' do
+          let(:file_path) { Refinery.roots('refinery/resources').join('spec/fixtures/refinery_is_secure.html') }
+
+          it 'the file is rejected', js: true do
+            expect(uploading_a_file).to_not change(Refinery::Resource, :count)
+
+            page.within_frame('dialog_iframe') do
+              expect(page).to have_content(::I18n.t('incorrect_format', scope: 'activerecord.errors.models.refinery/resource'))
+            end
+          end
+        end
+
+        describe 'max file size' do
           before do
             allow(Refinery::Resources).to receive(:max_file_size).and_return('1224')
           end
 
-          context "in english" do
+          context 'in english' do
             before do
               allow(Refinery::I18n).to receive(:current_locale).and_return(:en)
             end
 
-            it "is shown" do
+            it 'is shown' do
               visit refinery.admin_resources_path
-              click_link "Upload new file"
+              click_link 'Upload new file'
 
               within('#file') do
-                expect(page).to have_selector("a[tooltip='The maximum file size is 1.2 KB.']")
+                expect(page).to have_selector('a[tooltip="The maximum file size is 1.2 KB."]')
               end
             end
           end
 
-          context "in danish" do
+          context 'in danish' do
             before do
               allow(Refinery::I18n).to receive(:current_locale).and_return(:da)
             end
 
-            it "is shown" do
+            it 'is shown' do
               visit refinery.admin_resources_path
 
-              click_link "Tilføj en ny fil"
-              within "#file" do
-                expect(page).to have_selector("a[tooltip='Filen må maksimalt fylde 1,2 KB.']")
+              click_link 'Tilføj en ny fil'
+              within '#file' do
+                expect(page).to have_selector('a[tooltip="Filen må maksimalt fylde 1,2 KB."]')
               end
             end
           end
         end
       end
 
-      context "edit/update" do
+      context 'edit/update' do
         let!(:resource) { FactoryBot.create(:resource) }
 
-        it "updates file" do
+        it 'updates file' do
           visit refinery.admin_resources_path
-          expect(page).to have_content("Refinery Is Awesome")
+          expect(page).to have_content('Cape Town Tide Table')
           expect(page).to have_selector("a[href='/refinery/resources/#{resource.id}/edit']")
 
-          click_link "Edit this file"
+          click_link 'Edit this file'
 
-          expect(page).to have_content("Refinery Is Awesome or replace it with this one...")
+          expect(page).to have_content('Cape Town Tide Table or replace it with this one...')
           expect(page).to have_selector("a[href*='/refinery/resources']")
 
-          attach_file "resource_file", Refinery.roots('refinery/resources').join("spec/fixtures/refinery_is_awesome2.txt")
-          click_button "Save"
+          attach_file 'resource_file', Refinery.roots('refinery/resources').join('spec/fixtures/cape-town-tide-table2.pdf')
+          click_button 'Save'
 
-          expect(page).to have_content("Refinery Is Awesome2")
+          expect(page).to have_content('Cape Town Tide Table2')
           expect(Refinery::Resource.count).to eq(1)
         end
 
-        describe "translate" do
+        describe 'translate' do
           before do
-            allow(Refinery::I18n).to receive(:frontend_locales).and_return([:en, :fr])
+            allow(Refinery::I18n).to receive(:frontend_locales).and_return(%i[en fr])
           end
 
-          it "can have a second locale added to it" do
+          it 'can have a second locale added to it' do
             visit refinery.admin_resources_path
-            expect(page).to have_content("Refinery Is Awesome")
+            expect(page).to have_content('Cape Town Tide Table')
             expect(page).to have_selector("a[href='/refinery/resources/#{resource.id}/edit']")
 
-            click_link "Edit this file"
+            click_link 'Edit this file'
 
-            within "#switch_locale_picker" do
-              click_link "FR"
+            within '#switch_locale_picker' do
+              click_link 'FR'
             end
 
-            fill_in "Title", :with => "Premier fichier"
-            click_button "Save"
+            fill_in 'Title', with: 'Premier fichier'
+            click_button 'Save'
 
             expect(page).to have_content("'Premier fichier' was successfully updated.")
             expect(Resource::Translation.count).to eq(1)
@@ -118,53 +137,52 @@ module Admin
         end
       end
 
-      context "destroy" do
+      context 'destroy' do
         let!(:resource) { FactoryBot.create(:resource) }
 
-        it "removes file" do
+        it 'removes file' do
           visit refinery.admin_resources_path
           expect(page).to have_selector("a[href='/refinery/resources/#{resource.id}']")
 
-          click_link "Remove this file forever"
+          click_link 'Remove this file forever'
 
-          expect(page).to have_content("'Refinery Is Awesome' was successfully removed.")
+          expect(page).to have_content("'Cape Town Tide Table' was successfully removed.")
           expect(Refinery::Resource.count).to eq(0)
         end
       end
 
-      context "download" do
+      context 'download' do
         let!(:resource) { FactoryBot.create(:resource) }
 
-        it "succeeds" do
+        it 'succeeds' do
           visit refinery.admin_resources_path
 
-          click_link "Download this file"
+          click_link 'Download this file'
 
-          expect(page).to have_content("http://www.refineryhq.com/")
+          expect(page.body[0, 4]).to eq('%PDF')
         end
 
         context 'when the extension is mounted with a named space' do
           before do
             Rails.application.routes.draw do
-              mount Refinery::Core::Engine, :at => "/about"
+              mount Refinery::Core::Engine, at: '/about'
             end
             Rails.application.routes_reloader.reload!
           end
 
           after do
             Rails.application.routes.draw do
-              mount Refinery::Core::Engine, :at => "/"
+              mount Refinery::Core::Engine, at: '/'
             end
           end
 
-          it "succeeds" do
+          it 'succeeds' do
             visit refinery.admin_resources_path
 
-            click_link "Download this file"
+            click_link 'Download this file'
 
-            expect(page).to have_content("http://www.refineryhq.com/")
+            expect(page.body[0, 4]).to eq('%PDF')
           end
-
         end
       end
     end
diff --git a/resources/spec/fixtures/cape-town-tide-table.pdf b/resources/spec/fixtures/cape-town-tide-table.pdf
new file mode 100644
index 0000000000..032a8a86c3
Binary files /dev/null and b/resources/spec/fixtures/cape-town-tide-table.pdf differ
diff --git a/resources/spec/fixtures/cape-town-tide-table2.pdf b/resources/spec/fixtures/cape-town-tide-table2.pdf
new file mode 100644
index 0000000000..032a8a86c3
Binary files /dev/null and b/resources/spec/fixtures/cape-town-tide-table2.pdf differ
diff --git a/resources/spec/fixtures/refinery_is_awesome.txt b/resources/spec/fixtures/refinery_is_awesome.txt
deleted file mode 100644
index 3ba158285d..0000000000
--- a/resources/spec/fixtures/refinery_is_awesome.txt
+++ /dev/null
@@ -1 +0,0 @@
-http://www.refineryhq.com/
diff --git a/resources/spec/fixtures/refinery_is_awesome2.txt b/resources/spec/fixtures/refinery_is_awesome2.txt
deleted file mode 100644
index 69d6068eee..0000000000
--- a/resources/spec/fixtures/refinery_is_awesome2.txt
+++ /dev/null
@@ -1 +0,0 @@
-http://refinerycms.com
\ No newline at end of file
diff --git a/resources/spec/fixtures/refinery_is_secure.html b/resources/spec/fixtures/refinery_is_secure.html
new file mode 100644
index 0000000000..780b652bf1
--- /dev/null
+++ b/resources/spec/fixtures/refinery_is_secure.html
@@ -0,0 +1 @@
+https://www.refinerycms.com/
\ No newline at end of file
diff --git a/resources/spec/models/refinery/resource_spec.rb b/resources/spec/models/refinery/resource_spec.rb
index 0e0327d241..2774c81709 100644
--- a/resources/spec/models/refinery/resource_spec.rb
+++ b/resources/spec/models/refinery/resource_spec.rb
@@ -1,61 +1,64 @@
+# frozen_string_literal: true
+
 require 'spec_helper'
 
 module Refinery
-  describe Resource, :type => :model do
+  describe Resource, type: :model do
     let(:resource) { FactoryBot.create(:resource) }
-    let(:titled_resource) { FactoryBot.create(:resource, resource_title: 'Resource Title')}
+    let(:titled_resource) { FactoryBot.create(:resource, resource_title: 'Resource Title') }
 
-    context "with valid attributes" do
-      it "should create successfully" do
+    context 'with valid attributes' do
+      it 'should create successfully' do
         expect(resource.errors).to be_empty
       end
     end
 
-    context "resource url" do
-      it "should respond to .url" do
+    context 'resource url' do
+      it 'should respond to .url' do
         expect(resource).to respond_to(:url)
       end
 
-      it "should not support thumbnailing like images do" do
+      it 'should not support thumbnailing like images do' do
         expect(resource).not_to respond_to(:thumbnail)
       end
 
-      it "should contain its filename at the end" do
+      it 'should contain its filename at the end' do
         expect(resource.url.split('/').last).to match(/\A#{resource.file_name}/)
       end
 
-      context "when Dragonfly.verify_urls is true" do
+      context 'when Dragonfly.verify_urls is true' do
         before do
           allow(Refinery::Resources).to receive(:dragonfly_verify_urls).and_return(true)
           ::Refinery::Dragonfly.configure!(Refinery::Resources)
         end
 
-        it "returns a url with an SHA parameter" do
+        it 'returns a url with an SHA parameter' do
           expect(resource.url).to match(/\?sha=[\da-fA-F]{16}\z/)
         end
       end
 
-      context "when Dragonfly.verify_urls is false" do
+      context 'when Dragonfly.verify_urls is false' do
         before do
           allow(Refinery::Resources).to receive(:dragonfly_verify_urls).and_return(false)
           ::Refinery::Dragonfly.configure!(Refinery::Resources)
         end
-        it "returns a url without an SHA parameter" do
+
+        it 'returns a url without an SHA parameter' do
           expect(resource.url).not_to match(/\?sha=[\da-fA-F]{16}\z/)
         end
       end
     end
 
-    describe "#type_of_content" do
-      it "returns formated mime type" do
-        expect(resource.type_of_content).to eq("text plain")
+    describe '#type_of_content' do
+      it 'returns formated mime type' do
+        expect(resource.type_of_content).to eq('application pdf')
       end
     end
 
-    describe "#title" do
+    describe '#title' do
       context 'when a specific title has not been given' do
-        it "returns a titleized version of the filename" do
-          expect(resource.title).to eq("Refinery Is Awesome")
+        it 'returns a titleized version of the filename' do
+          expect(resource.title).to eq('Cape Town Tide Table')
         end
       end
       context 'when a specific title has been given' do
@@ -65,93 +68,113 @@ module Refinery
       end
     end
 
-    describe ".per_page" do
-      context "dialog is true" do
-        it "returns resource count specified by Resources.pages_per_dialog option" do
+    describe '.per_page' do
+      context 'dialog is true' do
+        it 'returns resource count specified by Resources.pages_per_dialog option' do
           expect(Resource.per_page(true)).to eq(Resources.pages_per_dialog)
         end
       end
 
-      context "dialog is false" do
-        it "returns resource count specified by Resources.pages_per_admin_index constant" do
+      context 'dialog is false' do
+        it 'returns resource count specified by Resources.pages_per_admin_index constant' do
           expect(Resource.per_page).to eq(Resources.pages_per_admin_index)
         end
       end
     end
 
-    describe ".create_resources" do
-      let(:file) { Refinery.roots('refinery/resources').join("spec/fixtures/refinery_is_awesome.txt") }
+    describe '.create_resources' do
+      let(:file) { Refinery.roots('refinery/resources').join('spec/fixtures/cape-town-tide-table.pdf') }
 
-      context "only one resource uploaded" do
-        it "returns an array containing one resource" do
-          expect(Resource.create_resources(:file => file).size).to eq(1)
+      context 'only one resource uploaded' do
+        it 'returns an array containing one resource' do
+          expect(Resource.create_resources(file: file).size).to eq(1)
         end
       end
 
-      context "many resources uploaded at once" do
-        it "returns an array containing all those resources" do
-          expect(Resource.create_resources(:file => [file, file, file]).size).to eq(3)
+      context 'many resources uploaded at once' do
+        it 'returns an array containing all those resources' do
+          expect(Resource.create_resources(file: [file, file, file]).size).to eq(3)
         end
       end
 
-      specify "each returned array item should be an instance of resource" do
-        Resource.create_resources(:file => [file, file, file]).each do |r|
-          expect(r).to be_an_instance_of(Resource)
+      specify 'each returned array item should be an instance of resource' do
+        Resource.create_resources(file: [file, file, file]).each do |resource|
+          expect(resource).to be_an_instance_of(Resource)
         end
       end
 
-      specify "each returned array item should be passed form parameters" do
-        params = {:file => [file, file, file], :fake_param => 'blah'}
+      specify 'each returned array item should be passed form parameters' do
+        params = { file: [file, file, file], fake_param: 'blah' }
 
-        expect(Resource).to receive(:create).exactly(3).times.with({:file => file, :fake_param => 'blah'})
+        expect(Resource).to receive(:create).exactly(3).times.with(file: file, fake_param: 'blah')
         Resource.create_resources(params)
       end
     end
 
-    describe "validations" do
-      describe "valid #file" do
+    describe 'validations' do
+      describe 'valid #file' do
+        before do
+          @file = Refinery.roots('refinery/resources').join('spec/fixtures/cape-town-tide-table.pdf')
+          Resources.max_file_size = (File.read(@file).size + 1000)
+        end
+
+        it 'should be valid when size does not exceed .max_file_size' do
+          expect(Resource.new(file: @file)).to be_valid
+        end
+      end
+
+      describe 'wrong mime_type #file' do
         before do
-          @file = Refinery.roots('refinery/resources').join("spec/fixtures/refinery_is_awesome.txt")
+          @file = Refinery.roots('refinery/resources').join('spec/fixtures/refinery_is_secure.html')
           Resources.max_file_size = (File.read(@file).size + 10)
+          @resource = Resource.new(file: @file)
+        end
+
+        it 'should not be valid when mime_type is not in .whitelisted_mime_types' do
+          expect(@resource).not_to be_valid
         end
 
-        it "should be valid when size does not exceed .max_file_size" do
-          expect(Resource.new(:file => @file)).to be_valid
+        it 'should contain an error message' do
+          @resource.valid?
+          expect(@resource.errors).not_to be_empty
+          expect(@resource.errors[:file]).to eq(Array(::I18n.t(
+                                                        'incorrect_format', scope: 'activerecord.errors.models.refinery/resource'
+                                                      )))
         end
       end
 
-      describe "too large #file" do
+      describe 'too large #file' do
         before do
-          @file = Refinery.roots('refinery/resources').join("spec/fixtures/refinery_is_awesome.txt")
+          @file = Refinery.roots('refinery/resources').join('spec/fixtures/cape-town-tide-table.pdf')
           Resources.max_file_size = (File.read(@file).size - 10)
-          @resource = Resource.new(:file => @file)
+          @resource = Resource.new(file: @file)
         end
 
-        it "should not be valid when size exceeds .max_file_size" do
+        it 'should not be valid when size exceeds .max_file_size' do
           expect(@resource).not_to be_valid
         end
 
-        it "should contain an error message" do
+        it 'should contain an error message' do
           @resource.valid?
           expect(@resource.errors).not_to be_empty
           expect(@resource.errors[:file]).to eq(Array(::I18n.t(
-            'too_big', :scope => 'activerecord.errors.models.refinery/resource',
-                       :size => Resources.max_file_size
-          )))
+                                                        'too_big', scope: 'activerecord.errors.models.refinery/resource',
+                                                                   size: Resources.max_file_size
+                                                      )))
         end
       end
 
-      describe "invalid argument for #file" do
+      describe 'invalid argument for #file' do
         before do
           @resource = Resource.new
         end
 
-        it "has an error message" do
+        it 'has an error message' do
           @resource.valid?
           expect(@resource.errors).not_to be_empty
           expect(@resource.errors[:file]).to eq(Array(::I18n.t(
-            'blank', :scope => 'activerecord.errors.models.refinery/resource'
-          )))
+                                                        'blank', scope: 'activerecord.errors.models.refinery/resource'
+                                                      )))
         end
       end
     end