Old Schedule Finder links redirect to SF 2.0

lib/dotcom_web/plugs/rewrite_urls.ex

@@ -25,6 +25,19 @@ defmodule DotcomWeb.Plugs.RewriteUrls do
     end
   end
 
+  # Send SF1.0 URLS to the new SF2.0
+  defp rewrite_url(
+         %{
+           path_info: ["schedules", _, "line"],
+           params: %{
+             "route" => route_id,
+             "schedule_finder" => %{"direction_id" => direction_id, "origin" => stop_id}
+           }
+         } = conn
+       ) do
+    "/departures/?route_id=#{route_id}&direction_id=#{direction_id}&stop_id=#{stop_id}"
+  end
+
   defp rewrite_url(%{path_info: ["schedules", "Boat-F3" | _]} = conn) do
     String.replace(conn.request_path, "Boat-F3", "Boat-F1")
   end
@@ -38,6 +51,10 @@ defmodule DotcomWeb.Plugs.RewriteUrls do
   end
 
   defp merge_url(base_url, query_string) do
-    "#{base_url}?#{query_string}"
+    if base_url |> String.contains?("?") do
+      "#{base_url}&#{query_string}"
+    else
+      "#{base_url}?#{query_string}"
+    end
   end
 end

test/dotcom_web/plugs/rewrite_urls_test.exs

@@ -11,6 +11,28 @@ defmodule DotcomWeb.Plugs.RewriteUrlsTest do
       assert conn.halted
     end
 
+    test "redirects if we're going to the old schedule finder", %{conn: conn} do
+      route_id = Faker.Pokemon.name()
+      direction_id = Faker.Util.pick(["0", "1"])
+      stop_id = Faker.Pokemon.name()
+
+      conn = %{
+        conn
+        | params: %{
+            "route" => route_id,
+            "schedule_finder" => %{"direction_id" => direction_id, "origin" => stop_id}
+          },
+          path_info: ["schedules", "red", "line"]
+      }
+
+      conn = call(conn, [])
+
+      assert redirected_to(conn, 302) ==
+               "/departures/?route_id=#{route_id}&direction_id=#{direction_id}&stop_id=#{stop_id}"
+
+      assert conn.halted
+    end
+
     test "includes a query string if present", %{conn: conn} do
       conn = %{
         conn