问如何在Bash测试中使用``bats mock`来断言对模拟脚本的调用

EN

get_timestamp () {
  # This should really be named get timestamp in milliseconds

  # In truth it wouldn't accept input ie the ${1} below,
  # but it is easier to show and test how it works with a fixed date (which is why we want to stub!)
  GIVEN_DATE="$1"
  # Pass in a human readable date and get back the epoch `%s` (seconds since 1-1-1970) and %N nanoseconds
  # date +%s.%N -d'Mon Apr 18 03:19:58.184561556 CDT 2016'
  EPOCH_NANO=$(date +%s.%N -d"$GIVEN_DATE")
  echo "This reflects the data the date stub would return: $EPOCH_NANO"
  # Accepts input in seconds.nanoseconds ie %s.%N and
  # sets the output format to milliseconds,
  # by combining the epoch `%s` (seconds since 1-1-1970) and
  # first 3 digits of the nanoseconds with %3N
  _DATE_ARGS='+%s%3N -d'
  echo $(date ${_DATE_ARGS}"@${EPOCH_NANO}")
}
get_timestamp 'Mon Apr 18 03:19:58.184561556 CDT 2016' # The quotes make it a *single* argument $1 to the function

# In bats you can declare globals outside your tests if you want them to apply
# to all tests in a file, or in a `fixture` or `vars` file and `load`or `source` it
declare -g _DATE_ARGS='+%s.%N -d'

# The interesting thing about the order of the mocked call returns is they are actually moving backwards in time,
# very interesting behavior and possibly needs another test that should throw a really big exception if this is encountered in the real world

# Original example below
@test "get_timestamp" {
  stub date \
      "${_DATE_ARGS} : echo 1460967598.184561556" \
      "${_DATE_ARGS} : echo 1460967598.084561556" \
      "${_DATE_ARGS} : echo 1460967598.004561556" \
      "${_DATE_ARGS} : echo 1460967598.000561556" \
      "${_DATE_ARGS} : echo 1460967598.000061556"

  run get_timestamp
  assert_success
  assert_output 1460967598184

  run get_timestamp
  assert_success
  assert_output 1460967598084

  run get_timestamp
  assert_success
  assert_output 1460967598004

  run get_timestamp
  assert_success
  assert_output 1460967598000

  run get_timestamp
  assert_success
  assert_output 1460967598000

  unstub date
}

@test "postgres.sh starts Postgres" {
  mock="$(mock_create)"
  mock_set_side_effect "${mock}" "echo $$ > /tmp/postgres_started"

  # Assuming postgres.sh expects the `_POSTGRES` variable to define a
  # path to the `postgres` executable
  _POSTGRES="${mock}" run postgres.sh

  [[ "${status}" -eq 0 ]]
  [[ "$(mock_get_call_num ${mock})" -eq 1 ]]
  [[ "$(mock_get_call_user ${mock})" = 'postgres' ]]
  [[ "$(mock_get_call_args ${mock})" =~ -D\ /var/lib/postgresql ]]
  [[ "$(mock_get_call_env ${mock} PGPORT)" -eq 5432 ]]
  [[ "$(cat /tmp/postgres_started)" -eq "$$" ]]
}

@test "get_timestamp" {
  mocked_command="date"
  mock="$(mock_create)"
  mock_path="${mock%/*}" # Parameter expansion to get the folder portion of the temp mock's path
  mock_file="${mock##*/}" # Parameter expansion to get the filename portion of the temp mock's path
  ln -sf "${mock_path}/${mock_file}" "${mock_path}/${mocked_command}"
  PATH="${mock_path}:$PATH" # Putting the stub at the beginning of the PATH so it gets picked up first
  mock_set_output "${mock}" "1460967598.184561556" 1
  mock_set_output "${mock}" "1460967598.084561556" 2
  mock_set_output "${mock}" "1460967598.004561556" 3
  mock_set_output "${mock}" "1460967598.000561556" 4
  mock_set_output "${mock}" "1460967598.000061556" 5
  mock_set_status "${mock}" 1 6

  run get_timestamp
  [[ "${status}" -eq 0 ]]
  run get_timestamp
  run get_timestamp
  run get_timestamp
  run get_timestamp
  [[ "${status}" -eq 0 ]]
  # Status is just of the previous invocation of `run`, so you can test every time or just once
  # note that calling the mock more times than you set the output for does NOT change the exit status...
  # unless you override it with `mock_set_status "${mock}" 1 6` 
  # Last bits are the exit code/status and index of call to return the status for
  # This is a test to assert that mocked_command stub is in the path and points the right place
  [[ "$(readlink -e $(which date))" == "$(readlink -e ${mock})" ]]
  # This is a direct call to the stubbed command to show that it returns the `mock_set_status` defined code and shows up in the call_num 
  run ${mocked_command}
  [[ "$status" -eq 1 ]]
  [[ "$(mock_get_call_num ${mock})" -eq 6 ]]
  # Check if your function exported something to the environment, the example get_timestamp function above does NOT
  # [[ "$(mock_get_call_env ${mock} _DATE_ARGS 1)" -eq '~%s%3N' ]]

  # Use the below line if you actually want to see all the arguments the function used to call the `date` 'stub'
  # echo "# call_args: " $(mock_get_call_args ${mock} 1) >&3

  # The actual args don't have the \ but the regex operator =~ treats + specially if it isn't escaped
  date_args="\+%s%3N"
  [[ "$(mock_get_call_args ${mock} 1)" =~ $date_args ]]

  # Cleanup our stub and fixup the PATH
  unlink "${mock_path}/${mocked_command}"
  PATH="${PATH/${mock_path}:/}"
}