Refactor fetching of remote resources (#11251)

app/helpers/jsonld_helper.rb

@@ -16,13 +16,15 @@ module JsonLdHelper
   # The url attribute can be a string, an array of strings, or an array of objects.
   # The objects could include a mimeType. Not-included mimeType means it's text/html.
   def url_to_href(value, preferred_type = nil)
-    single_value = if value.is_a?(Array) && !value.first.is_a?(String)
-                     value.find { |link| preferred_type.nil? || ((link['mimeType'].presence || 'text/html') == preferred_type) }
-                   elsif value.is_a?(Array)
-                     value.first
-                   else
-                     value
-                   end
+    single_value = begin
+      if value.is_a?(Array) && !value.first.is_a?(String)
+        value.find { |link| preferred_type.nil? || ((link['mimeType'].presence || 'text/html') == preferred_type) }
+      elsif value.is_a?(Array)
+        value.first
+      else
+        value
+      end
+    end
 
     if single_value.nil? || single_value.is_a?(String)
       single_value
@@ -64,7 +66,9 @@ module JsonLdHelper
   def fetch_resource(uri, id, on_behalf_of = nil)
     unless id
       json = fetch_resource_without_id_validation(uri, on_behalf_of)
+
       return unless json
+
       uri = json['id']
     end
 
@@ -74,24 +78,26 @@ module JsonLdHelper
 
   def fetch_resource_without_id_validation(uri, on_behalf_of = nil, raise_on_temporary_error = false)
     build_request(uri, on_behalf_of).perform do |response|
-      unless response_successful?(response) || response_error_unsalvageable?(response) || !raise_on_temporary_error
-        raise Mastodon::UnexpectedResponseError, response
-      end
+      raise Mastodon::UnexpectedResponseError, response unless response_successful?(response) || response_error_unsalvageable?(response) || !raise_on_temporary_error
+
       return body_to_json(response.body_with_limit) if response.code == 200
     end
+
     # If request failed, retry without doing it on behalf of a user
     return if on_behalf_of.nil?
+
     build_request(uri).perform do |response|
-      unless response_successful?(response) || response_error_unsalvageable?(response) || !raise_on_temporary_error
-        raise Mastodon::UnexpectedResponseError, response
-      end
+      raise Mastodon::UnexpectedResponseError, response unless response_successful?(response) || response_error_unsalvageable?(response) || !raise_on_temporary_error
+
       response.code == 200 ? body_to_json(response.body_with_limit) : nil
     end
   end
 
   def body_to_json(body, compare_id: nil)
     json = body.is_a?(String) ? Oj.load(body, mode: :strict) : body
+
     return if compare_id.present? && json['id'] != compare_id
+
     json
   rescue Oj::ParseError
     nil
@@ -105,35 +111,34 @@ module JsonLdHelper
     end
   end
 
-  private
-
   def response_successful?(response)
     (200...300).cover?(response.code)
   end
 
   def response_error_unsalvageable?(response)
-    (400...500).cover?(response.code) && response.code != 429
+    response.code == 501 || ((400...500).cover?(response.code) && ![401, 408, 429].include?(response.code))
   end
 
   def build_request(uri, on_behalf_of = nil)
-    request = Request.new(:get, uri)
-    request.on_behalf_of(on_behalf_of) if on_behalf_of
-    request.add_headers('Accept' => 'application/activity+json, application/ld+json')
-    request
+    Request.new(:get, uri).tap do |request|
+      request.on_behalf_of(on_behalf_of) if on_behalf_of
+      request.add_headers('Accept' => 'application/activity+json, application/ld+json')
+    end
   end
 
   def load_jsonld_context(url, _options = {}, &_block)
     json = Rails.cache.fetch("jsonld:context:#{url}", expires_in: 30.days, raw: true) do
       request = Request.new(:get, url)
       request.add_headers('Accept' => 'application/ld+json')
-
       request.perform do |res|
         raise JSON::LD::JsonLdError::LoadingDocumentFailed unless res.code == 200 && res.mime_type == 'application/ld+json'
+
         res.body_with_limit
       end
     end
 
     doc = JSON::LD::API::RemoteDocument.new(url, json)
+
     block_given? ? yield(doc) : doc
   end
 end