Extend MastoAPI to provide attachment mimetypes

docs/Differences-in-MastodonAPI-Responses.md

@@ -20,6 +20,12 @@ Has these additional fields under the `pleroma` object:
 
 - `local`: true if the post was made on the local instance.
 
+## Attachments
+
+Has these additional fields under the `pleroma` object:
+
+- `mime_type`: mime type of the attachment.
+
 ## Accounts
 
 - `/api/v1/accounts/:id`: The `id` parameter can also be the `nickname` of the user. This only works in this endpoint, not the deeper nested ones for following etc.

lib/pleroma/web/mastodon_api/views/status_view.ex

@@ -257,7 +257,8 @@ def render("attachment.json", %{attachment: attachment}) do
       preview_url: href,
       text_url: href,
       type: type,
-      description: attachment["name"]
+      description: attachment["name"],
+      pleroma: %{mime_type: media_type}
     }
   end
 

test/web/mastodon_api/status_view_test.exs

@@ -196,7 +196,8 @@ test "attachments" do
       remote_url: "someurl",
       preview_url: "someurl",
       text_url: "someurl",
-      description: nil
+      description: nil,
+      pleroma: %{mime_type: "image/png"}
     }
 
     assert expected == StatusView.render("attachment.json", %{attachment: object})