Merge pull request #2748 from alphagov/warn-filter-editions

Add a warning and a TODO for the filter_editions method

app/models/link.rb

@@ -9,6 +9,12 @@ class Link < ApplicationRecord
   validate :association_presence
 
   def self.filter_editions(scope, filters)
+    if filters.size > 1
+      # TODO: richard.towers - temporary warning to check whether this method is ever
+      #       called with multiple filters. The code looks wrong, so if it's not being
+      #       called we should make this an error and only support a single filter.
+      logger.warn("filter_editions called with multiple filters. These will be ANDed together in a way that probably isn't what we want. Filters were: #{filters.inspect}")
+    end
     join_sql = <<-SQL.strip_heredoc
       INNER JOIN link_sets ON link_sets.content_id = documents.content_id
       INNER JOIN links ON links.link_set_id = link_sets.id

docs/api.md

@@ -381,8 +381,7 @@ and a state has been specified, the draft is returned.
     e.g. `link_organisations=056a9ff6-2ed1-4942-9f06-92df03da741d`
     will restrict the documents returned to those that have a link
     with type `organisations` to the document with specified content
-    id. Query parameters matching this form can be specified multiple
-    times.
+    id.
 - `locale` *(optional, default "en")*
   - Accepts: An available locale from the [Rails I18n gem][i18n-gem]
   - Used to restrict documents to a given locale.