Add missing image model spec. Add shared specs to check image validations at any imageable model

spec/shared/models/image_validations.rb

@@ -0,0 +1,70 @@
+shared_examples "image validations" do |imageable_factory|
+  include ImagesHelper
+  include ImageablesHelper
+
+  let!(:image)                  { build(:image, imageable_factory.to_sym) }
+  let!(:imageable)              { image.imageable }
+  let!(:acceptedcontenttypes)   { imageable_accepted_content_types }
+
+  it "should be valid" do
+    expect(image).to be_valid
+  end
+
+  it "should not be valid without a title" do
+    image.title = nil
+
+    expect(image).to_not be_valid
+  end
+
+  it "should not be valid without an attachment" do
+    image.attachment = nil
+
+    expect(image).to_not be_valid
+  end
+
+  it "should be valid for all accepted content types" do
+    acceptedcontenttypes.each do |content_type|
+      extension = content_type.split("/").last
+      image.attachment = File.new("spec/fixtures/files/clippy.#{extension}")
+
+      expect(image).to be_valid
+    end
+  end
+
+  it "should not be valid for png and gif image content types" do
+    ["gif", "png"].each do |content_type|
+      extension = content_type.split("/").last
+      image.attachment = File.new("spec/fixtures/files/clippy.#{extension}")
+
+      expect(image).not_to be_valid
+    end
+  end
+
+  it "should not be valid for attachments larger than imageable max_file_size definition" do
+    image.stub(:attachment_file_size).and_return(Image::MAX_IMAGE_SIZE + 1.byte)
+
+    expect(image).to_not be_valid
+    expect(image.errors[:attachment]).to include "must be in between 0 Bytes and 1 MB"
+  end
+
+  it "should not be valid without a user_id" do
+    image.user_id = nil
+
+    expect(image).to_not be_valid
+  end
+
+  it "should not be valid without a imageable_id" do
+    image.save
+    image.imageable_id = nil
+
+    expect(image).to_not be_valid
+  end
+
+  it "should not be valid without a imageable_type" do
+    image.save
+    image.imageable_type = nil
+
+    expect(image).to_not be_valid
+  end
+
+end