(command.CommandList
  children: [
    (command.Assignment
      keyword: Assign_None
      pairs: [
        (assign_pair
          lhs: (lhs_expr.LhsName name:test_description)
          op: Equal
          rhs: {(SQ <'various @{whatever} syntax tests'>)}
        )
      ]
    )
    (C {(.)} {(./test-lib.sh)})
    (C {(test_expect_success)} {(SQ <setup>)} 
      {(SQ <'\n'> <'\ttest_commit one &&\n'> <'\ttest_commit two\n'>)}
    )
    (command.FuncDef
      name: check_at
      body: 
        (command.BraceGroup
          children: [
            (command.AndOr
              ops: [Op_DAmp Op_DAmp]
              children: [
                (command.SimpleCommand
                  words: [{(echo)} {(DQ ($ VSub_Number '$2'))}]
                  redirects: [(redir.Redir op:<Redir_Great '>'> fd:16777215 arg_word:{(expect)})]
                )
                (command.SimpleCommand
                  words: [
                    {(git)}
                    {(log)}
                    {(-1)}
                    {(--format) (Lit_Other '=') (Lit_Other '%') (s)}
                    {(DQ ($ VSub_Number '$1'))}
                  ]
                  redirects: [(redir.Redir op:<Redir_Great '>'> fd:16777215 arg_word:{(actual)})]
                )
                (C {(test_cmp)} {(expect)} {(actual)})
              ]
            )
          ]
        )
    )
    (C {(test_expect_success)} {(SQ <'@{0} shows current'>)} {(SQ <'\n'> <'\tcheck_at @{0} two\n'>)})
    (C {(test_expect_success)} {(SQ <'@{1} shows old'>)} {(SQ <'\n'> <'\tcheck_at @{1} one\n'>)})
    (C {(test_expect_success)} {(SQ <'@{now} shows current'>)} {(SQ <'\n'> <'\tcheck_at @{now} two\n'>)})
    (C {(test_expect_success)} {(SQ <'@{2001-09-17} (before the first commit) shows old'>)} 
      {(SQ <'\n'> <'\tcheck_at @{2001-09-17} one\n'>)}
    )
    (C {(test_expect_success)} {(SQ <'silly approxidates work'>)} 
      {(SQ <'\n'> <'\tcheck_at @{3.hot.dogs.on.2001-09-17} one\n'>)}
    )
    (C {(test_expect_success)} {(SQ <'notice misspelled upstream'>)} 
      {(SQ <'\n'> <'\ttest_must_fail git log -1 --format=%s @{usptream}\n'>)}
    )
    (C {(test_expect_success)} {(SQ <'complain about total nonsense'>)} 
      {(SQ <'\n'> <'\ttest_must_fail git log -1 --format=%s @{utter.bogosity}\n'>)}
    )
    (C {(test_done)})
  ]
)