Support getting pages with empty ?url param (#1293)

This treats `?url=` and `?url=*` querystrings the same as not specifying `url` at all. That’s a slight improvement for the second case and makes the first case work (previously it guaranteed no results, since no URL can match the empty string!).

Author: Mr0grog

app/controllers/api/v0/pages_controller.rb

@@ -165,7 +165,7 @@ def page_collection
       }.compact)
     end
 
-    if params[:url]
+    if params[:url].present? && params[:url] != '*'
       query = params[:url]
       collection = collection.joins(:urls)
       if query.include? '*'

test/controllers/api/v0/pages_controller_test.rb

@@ -117,6 +117,28 @@ def chunk_size_in_url(url)
                         'Results included pages not matching filtered URL'
   end
 
+  test 'filtering URL with empty string is the same as no filter' do
+    sign_in users(:alice)
+    all_ids = Page.all.pluck(:uuid).sort
+    get '/api/v0/pages/?url='
+    body_json = JSON.parse @response.body
+    ids = body_json['data'].pluck('uuid').sort
+
+    assert_equal all_ids, ids
+    assert_not ids.empty?
+  end
+
+  test 'filtering URL with "*" is the same as no filter' do
+    sign_in users(:alice)
+    all_ids = Page.all.pluck(:uuid).sort
+    get '/api/v0/pages/?url=*'
+    body_json = JSON.parse @response.body
+    ids = body_json['data'].pluck('uuid').sort
+
+    assert_equal all_ids, ids
+    assert_not ids.empty?
+  end
+
   test 'can filter pages by version source_type' do
     sign_in users(:alice)
     get api_v0_pages_path(source_type: 'pagefreezer')