fanbox: don't raise error on age-restricted posts.

Prevent age-restricted fanbox posts from raising errors when source data
is fetched. This prevents error messages from being shown to users when
switching to the edit tab on a post.

This will cause uploads of age-restricted posts to fail with an
unrelated error because we either can't find the image url (if we were
given only the html page) or we can't download the image (because we're
not logged in to Fanbox).

app/logical/sources/strategies/fanbox.rb

@@ -105,11 +105,7 @@ module Sources
       end
 
       def display_name
-        if api_response.present?
-          api_response["user"]["name"]
-        elsif artist_api_response.present?
-          artist_api_response["user"]["name"]
-        end
+        api_response.dig("user", "name") || artist_api_response.dig("user", "name")
       end
 
       def other_names
@@ -125,8 +121,9 @@ module Sources
       end
 
       def artist_commentary_desc
-        return if api_response.blank?
         body = api_response["body"]
+        return if body.blank?
+
         if body["text"].present?
           body["text"]
         elsif body["blocks"].present?
@@ -160,11 +157,12 @@ module Sources
         return {} if illust_id.blank?
         resp = client.get("https://api.fanbox.cc/post.info?postId=#{illust_id}")
         json_response = JSON.parse(resp)["body"]
-        if json_response["restrictedFor"] == 2 && json_response["body"].blank?
-          # Pixiv Fanbox login is protected by Google Recaptcha, so it's not possible for us to extract anything from them (save for the title).
-          # Other projects like PixivUtils ask the user to periodically extract cookies from the browser, but this is not feasible for Danbooru.
-          raise Sources::Error, "Age-restricted posts from Pixiv Fanbox are not supported."
-        end
+
+        # Pixiv Fanbox login is protected by Google Recaptcha, so it's not
+        # possible for us to extract anything from them (save for the title).
+        # Other projects like PixivUtils ask the user to periodically extract
+        # cookies from the browser, but this is not feasible for Danbooru.
+        return {} if json_response["restrictedFor"] == 2 && json_response["body"].blank?
 
         json_response
       rescue JSON::ParserError
@@ -181,7 +179,7 @@ module Sources
       end
 
       def client
-        Danbooru::Http.headers(Origin: "https://fanbox.cc").cache(1.minute)
+        @client ||= http.headers(Origin: "https://fanbox.cc").cache(1.minute)
       end
     end
   end

test/functional/uploads_controller_test.rb

@@ -371,6 +371,9 @@ class UploadsControllerTest < ActionDispatch::IntegrationTest
         should_upload_successfully("https://art.ngfiles.com/images/1254000/1254722_natthelich_pandora.jpg")
         should_upload_successfully("https://art.ngfiles.com/comments/57000/iu_57615_7115981.jpg")
         should_upload_successfully("https://www.newgrounds.com/art/view/puddbytes/costanza-at-bat")
+
+        should_upload_successfully("https://www.fanbox.cc/@tsukiori/posts/1080657")
+        should_upload_successfully("https://downloads.fanbox.cc/images/post/1080657/SaakPC251KafLL6jIo1WPPmr.png")
       end
     end
   end

test/unit/sources/fanbox.rb

@@ -90,6 +90,15 @@ module Sources
       end
     end
 
+    context "an age-restricted fanbox post" do
+      should "not raise an error" do
+        @source = Sources::Strategies.find("https://mfr.fanbox.cc/posts/1306390")
+
+        assert_nothing_raised { @source.to_h }
+        assert_equal("mfr", @source.artist_name)
+      end
+    end
+
     context "A link in the old format" do
       should "still work" do
         post = Sources::Strategies.find("https://www.pixiv.net/fanbox/creator/1566167/post/39714")