Skip generating smaller designs for TIFFs

Our ability to enable the feature to generate smaller design images
https://gitlab.com/gitlab-org/gitlab/-/issues/207351 was blocked when it
was discovered that our servers did not have the ability to generate
JPG or TIFF https://gitlab.com/gitlab-org/gitlab/-/issues/207740.

The developer who is working on allowing our infrastructure to resize
images has enabled JPGs to be resized in production, however TIFF
support may take a couple more weeks
https://gitlab.com/gitlab-org/gitlab/-/issues/207740#note_316655702.

We've decided to make a change to skip resizing TIFFs for now, and then
go ahead and enable the resizing feature, rather than to hold it up any
longer. We can then do a follow-up issue to enable TIFF when we have it.

https://gitlab.com/gitlab-org/gitlab/-/issues/213468

ee/app/uploaders/design_management/design_v432x230_uploader.rb

@@ -12,9 +12,15 @@ module DesignManagement
     include ObjectStorage::Concern
     prepend ObjectStorage::Extension::RecordsUploads
 
-    # We currently cannot resize `image/ico` or `image/svg+xml` mime types.
-    # See https://gitlab.com/gitlab-org/gitlab/issues/207069
-    MIME_TYPE_WHITELIST = %w(image/png image/jpeg image/bmp image/gif image/tiff).freeze
+    # We choose not to resize `image/ico` as we assume there will be no
+    # benefit in generating an 432x230 sized icon.
+    #
+    # We currently cannot resize `image/tiff`.
+    # See https://gitlab.com/gitlab-org/gitlab/issues/207740
+    #
+    # We currently choose not to resize `image/svg+xml` for security reasons.
+    # See https://gitlab.com/gitlab-org/gitlab/issues/207740#note_302766171
+    MIME_TYPE_WHITELIST = %w(image/png image/jpeg image/bmp image/gif).freeze
 
     process resize_to_fit: [432, 230]
 

ee/spec/services/design_management/generate_image_versions_service_spec.rb

@@ -15,6 +15,14 @@ describe DesignManagement::GenerateImageVersionsService do
         .from(nil).to(CarrierWave::SanitizedFile)
     end
 
+    it 'skips generating image versions if the mime type is not whitelisted' do
+      stub_const('DesignManagement::DesignV432x230Uploader::MIME_TYPE_WHITELIST', [])
+
+      described_class.new(version).execute
+
+      expect(action.reload.image_v432x230.file).to eq(nil)
+    end
+
     it 'skips generating image versions if the design file size is too large' do
       stub_const("#{described_class.name}::MAX_DESIGN_SIZE", 1.byte)