Update test/ex_doc/formatter/html_test.exs

Co-authored-by: José Valim <[email protected]>

Author: zachdaniel

test/ex_doc/formatter/html_test.exs

@@ -625,7 +625,7 @@ defmodule ExDoc.Formatter.HTMLTest do
              ] =
                Jason.decode!(content)["extras"]
                |> Enum.find(&(&1["id"] == "readme"))
-               |> Map.get("searchData")
+               |> Map.fetch!("searchData")
     end
 
     test "containing settext headers while discarding links on header",