Ingest blurhash for attachments if they were federated

lib/pleroma/web/activity_pub/object_validators/attachment_validator.ex

@@ -15,6 +15,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.AttachmentValidator do
     field(:type, :string)
     field(:mediaType, :string, default: "application/octet-stream")
     field(:name, :string)
+    field(:blurhash, :string)
 
     embeds_many :url, UrlObjectValidator, primary_key: false do
       field(:type, :string)
@@ -41,7 +42,7 @@ def changeset(struct, data) do
       |> fix_url()
 
     struct
-    |> cast(data, [:type, :mediaType, :name])
+    |> cast(data, [:type, :mediaType, :name, :blurhash])
     |> cast_embed(:url, with: &url_changeset/2)
     |> validate_inclusion(:type, ~w[Link Document Audio Image Video])
     |> validate_required([:type, :mediaType, :url])

test/pleroma/web/activity_pub/object_validators/attachment_validator_test.exs

@@ -33,7 +33,8 @@ test "it turns mastodon attachments into our attachments" do
           "http://mastodon.example.org/system/media_attachments/files/000/000/002/original/334ce029e7bfb920.jpg",
         "type" => "Document",
         "name" => nil,
-        "mediaType" => "image/jpeg"
+        "mediaType" => "image/jpeg",
+        "blurhash" => "UD9jJz~VSbR#xT$~%KtQX9R,WAs9RjWBs:of"
       }
 
       {:ok, attachment} =
@@ -50,6 +51,7 @@ test "it turns mastodon attachments into our attachments" do
              ] = attachment.url
 
       assert attachment.mediaType == "image/jpeg"
+      assert attachment.blurhash == "UD9jJz~VSbR#xT$~%KtQX9R,WAs9RjWBs:of"
     end
 
     test "it handles our own uploads" do