add more tests

Author: IanButterworth

test/file.jl

@@ -1441,6 +1441,10 @@ rm(dirwalk, recursive=true)
                 touch(randstring())
             end
             @test issorted(readdir())
+            @test issorted(readdirx())
+            @test map(o->o.name, readdirx()) == readdir()
+            @test map(o->o.path, readdirx()) == readdir(join=true)
+            @test count(isfile, readdir(join=true)) == count(isfile, readdirx())
         end
     end
 end