diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 00000000..0ed2caff
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,9 @@
+[submodule "test/bats"]
+	path = test/bats
+	url = https://github.com/sstephenson/bats
+[submodule "test/test_helper/bats-support"]
+	path = test/test_helper/bats-support
+	url = https://github.com/ztombol/bats-support
+[submodule "test/test_helper/bats-assert"]
+	path = test/test_helper/bats-assert
+	url = https://github.com/ztombol/bats-assert
diff --git a/Makefile b/Makefile
index 980f4927..aaed30f9 100644
--- a/Makefile
+++ b/Makefile
@@ -145,7 +145,7 @@ fixtures:
 
 tests:
 	# Start tests
-	./test/bats/bats test/tests.bats
+	./test/bats/bin/bats test/tests.bats
 
 clean:
 	# Remove running test containers
diff --git a/test/bats b/test/bats
new file mode 160000
index 00000000..03608115
--- /dev/null
+++ b/test/bats
@@ -0,0 +1 @@
+Subproject commit 03608115df2071fff4eaaff1605768c275e5f81f
diff --git a/test/bats/bats b/test/bats/bats
deleted file mode 100755
index 7e1c9eda..00000000
--- a/test/bats/bats
+++ /dev/null
@@ -1,142 +0,0 @@
-#!/usr/bin/env bash
-set -e
-
-version() {
-  echo "Bats 0.4.0"
-}
-
-usage() {
-  version
-  echo "Usage: bats [-c] [-p | -t] <test> [<test> ...]"
-}
-
-help() {
-  usage
-  echo
-  echo "  <test> is the path to a Bats test file, or the path to a directory"
-  echo "  containing Bats test files."
-  echo
-  echo "  -c, --count    Count the number of test cases without running any tests"
-  echo "  -h, --help     Display this help message"
-  echo "  -p, --pretty   Show results in pretty format (default for terminals)"
-  echo "  -t, --tap      Show results in TAP format"
-  echo "  -v, --version  Display the version number"
-  echo
-  echo "  For more information, see https://github.com/sstephenson/bats"
-  echo
-}
-
-resolve_link() {
-  $(type -p greadlink readlink | head -1) "$1"
-}
-
-abs_dirname() {
-  local cwd="$(pwd)"
-  local path="$1"
-
-  while [ -n "$path" ]; do
-    cd "${path%/*}"
-    local name="${path##*/}"
-    path="$(resolve_link "$name" || true)"
-  done
-
-  pwd
-  cd "$cwd"
-}
-
-expand_path() {
-  { cd "$(dirname "$1")" 2>/dev/null
-    local dirname="$PWD"
-    cd "$OLDPWD"
-    echo "$dirname/$(basename "$1")"
-  } || echo "$1"
-}
-
-BATS_LIBEXEC="$(abs_dirname "$0")"
-export BATS_PREFIX="$(abs_dirname "$BATS_LIBEXEC")"
-export BATS_CWD="$(abs_dirname .)"
-export PATH="$BATS_LIBEXEC:$PATH"
-
-options=()
-arguments=()
-for arg in "$@"; do
-  if [ "${arg:0:1}" = "-" ]; then
-    if [ "${arg:1:1}" = "-" ]; then
-      options[${#options[*]}]="${arg:2}"
-    else
-      index=1
-      while option="${arg:$index:1}"; do
-        [ -n "$option" ] || break
-        options[${#options[*]}]="$option"
-        let index+=1
-      done
-    fi
-  else
-    arguments[${#arguments[*]}]="$arg"
-  fi
-done
-
-unset count_flag pretty
-[ -t 0 ] && [ -t 1 ] && pretty="1"
-[ -n "$CI" ] && pretty=""
-
-for option in "${options[@]}"; do
-  case "$option" in
-  "h" | "help" )
-    help
-    exit 0
-    ;;
-  "v" | "version" )
-    version
-    exit 0
-    ;;
-  "c" | "count" )
-    count_flag="-c"
-    ;;
-  "t" | "tap" )
-    pretty=""
-    ;;
-  "p" | "pretty" )
-    pretty="1"
-    ;;
-  * )
-    usage >&2
-    exit 1
-    ;;
-  esac
-done
-
-if [ "${#arguments[@]}" -eq 0 ]; then
-  usage >&2
-  exit 1
-fi
-
-filenames=()
-for filename in "${arguments[@]}"; do
-  if [ -d "$filename" ]; then
-    shopt -s nullglob
-    for suite_filename in "$(expand_path "$filename")"/*.bats; do
-      filenames["${#filenames[@]}"]="$suite_filename"
-    done
-    shopt -u nullglob
-  else
-    filenames["${#filenames[@]}"]="$(expand_path "$filename")"
-  fi
-done
-
-if [ "${#filenames[@]}" -eq 1 ]; then
-  command="bats-exec-test"
-else
-  command="bats-exec-suite"
-fi
-
-if [ -n "$pretty" ]; then
-  extended_syntax_flag="-x"
-  formatter="bats-format-tap-stream"
-else
-  extended_syntax_flag=""
-  formatter="cat"
-fi
-
-set -o pipefail execfail
-exec "$command" $count_flag $extended_syntax_flag "${filenames[@]}" | "$formatter"
\ No newline at end of file
diff --git a/test/bats/bats-exec-suite b/test/bats/bats-exec-suite
deleted file mode 100755
index 29ab255d..00000000
--- a/test/bats/bats-exec-suite
+++ /dev/null
@@ -1,55 +0,0 @@
-#!/usr/bin/env bash
-set -e
-
-count_only_flag=""
-if [ "$1" = "-c" ]; then
-  count_only_flag=1
-  shift
-fi
-
-extended_syntax_flag=""
-if [ "$1" = "-x" ]; then
-  extended_syntax_flag="-x"
-  shift
-fi
-
-trap "kill 0; exit 1" int
-
-count=0
-for filename in "$@"; do
-  let count+="$(bats-exec-test -c "$filename")"
-done
-
-if [ -n "$count_only_flag" ]; then
-  echo "$count"
-  exit
-fi
-
-echo "1..$count"
-status=0
-offset=0
-for filename in "$@"; do
-  index=0
-  {
-    IFS= read -r # 1..n
-    while IFS= read -r line; do
-      case "$line" in
-      "begin "* )
-        let index+=1
-        echo "${line/ $index / $(($offset + $index)) }"
-        ;;
-      "ok "* | "not ok "* )
-        [ -n "$extended_syntax_flag" ] || let index+=1
-        echo "${line/ $index / $(($offset + $index)) }"
-        [ "${line:0:6}" != "not ok" ] || status=1
-        ;;
-      * )
-        echo "$line"
-        ;;
-      esac
-    done
-  } < <( bats-exec-test $extended_syntax_flag "$filename" )
-  offset=$(($offset + $index))
-done
-
-exit "$status"
diff --git a/test/bats/bats-exec-test b/test/bats/bats-exec-test
deleted file mode 100755
index 8f3bd510..00000000
--- a/test/bats/bats-exec-test
+++ /dev/null
@@ -1,346 +0,0 @@
-#!/usr/bin/env bash
-set -e
-set -E
-set -T
-
-BATS_COUNT_ONLY=""
-if [ "$1" = "-c" ]; then
-  BATS_COUNT_ONLY=1
-  shift
-fi
-
-BATS_EXTENDED_SYNTAX=""
-if [ "$1" = "-x" ]; then
-  BATS_EXTENDED_SYNTAX="$1"
-  shift
-fi
-
-BATS_TEST_FILENAME="$1"
-if [ -z "$BATS_TEST_FILENAME" ]; then
-  echo "usage: bats-exec <filename>" >&2
-  exit 1
-elif [ ! -f "$BATS_TEST_FILENAME" ]; then
-  echo "bats: $BATS_TEST_FILENAME does not exist" >&2
-  exit 1
-else
-  shift
-fi
-
-BATS_TEST_DIRNAME="$(dirname "$BATS_TEST_FILENAME")"
-BATS_TEST_NAMES=()
-
-load() {
-  local name="$1"
-  local filename
-
-  if [ "${name:0:1}" = "/" ]; then
-    filename="${name}"
-  else
-    filename="$BATS_TEST_DIRNAME/${name}.bash"
-  fi
-
-  [ -f "$filename" ] || {
-    echo "bats: $filename does not exist" >&2
-    exit 1
-  }
-
-  source "${filename}"
-}
-
-run() {
-  local e E T oldIFS
-  [[ ! "$-" =~ e ]] || e=1
-  [[ ! "$-" =~ E ]] || E=1
-  [[ ! "$-" =~ T ]] || T=1
-  set +e
-  set +E
-  set +T
-  output="$("$@" 2>&1)"
-  status="$?"
-  oldIFS=$IFS
-  IFS=$'\n' lines=($output)
-  [ -z "$e" ] || set -e
-  [ -z "$E" ] || set -E
-  [ -z "$T" ] || set -T
-  IFS=$oldIFS
-}
-
-setup() {
-  true
-}
-
-teardown() {
-  true
-}
-
-skip() {
-  BATS_TEST_SKIPPED=${1:-1}
-  BATS_TEST_COMPLETED=1
-  exit 0
-}
-
-bats_test_begin() {
-  BATS_TEST_DESCRIPTION="$1"
-  if [ -n "$BATS_EXTENDED_SYNTAX" ]; then
-    echo "begin $BATS_TEST_NUMBER $BATS_TEST_DESCRIPTION" >&3
-  fi
-  setup
-}
-
-bats_test_function() {
-  local test_name="$1"
-  BATS_TEST_NAMES["${#BATS_TEST_NAMES[@]}"]="$test_name"
-}
-
-bats_capture_stack_trace() {
-  BATS_PREVIOUS_STACK_TRACE=( "${BATS_CURRENT_STACK_TRACE[@]}" )
-  BATS_CURRENT_STACK_TRACE=()
-
-  local test_pattern=" $BATS_TEST_NAME $BATS_TEST_SOURCE"
-  local setup_pattern=" setup $BATS_TEST_SOURCE"
-  local teardown_pattern=" teardown $BATS_TEST_SOURCE"
-
-  local frame
-  local index=1
-
-  while frame="$(caller "$index")"; do
-    BATS_CURRENT_STACK_TRACE["${#BATS_CURRENT_STACK_TRACE[@]}"]="$frame"
-    if [[ "$frame" = *"$test_pattern"     || \
-          "$frame" = *"$setup_pattern"    || \
-          "$frame" = *"$teardown_pattern" ]]; then
-      break
-    else
-      let index+=1
-    fi
-  done
-
-  BATS_SOURCE="$(bats_frame_filename "${BATS_CURRENT_STACK_TRACE[0]}")"
-  BATS_LINENO="$(bats_frame_lineno "${BATS_CURRENT_STACK_TRACE[0]}")"
-}
-
-bats_print_stack_trace() {
-  local frame
-  local index=1
-  local count="${#@}"
-
-  for frame in "$@"; do
-    local filename="$(bats_trim_filename "$(bats_frame_filename "$frame")")"
-    local lineno="$(bats_frame_lineno "$frame")"
-
-    if [ $index -eq 1 ]; then
-      echo -n "# ("
-    else
-      echo -n "#  "
-    fi
-
-    local fn="$(bats_frame_function "$frame")"
-    if [ "$fn" != "$BATS_TEST_NAME" ]; then
-      echo -n "from function \`$fn' "
-    fi
-
-    if [ $index -eq $count ]; then
-      echo "in test file $filename, line $lineno)"
-    else
-      echo "in file $filename, line $lineno,"
-    fi
-
-    let index+=1
-  done
-}
-
-bats_print_failed_command() {
-  local frame="$1"
-  local status="$2"
-  local filename="$(bats_frame_filename "$frame")"
-  local lineno="$(bats_frame_lineno "$frame")"
-
-  local failed_line="$(bats_extract_line "$filename" "$lineno")"
-  local failed_command="$(bats_strip_string "$failed_line")"
-  echo -n "#   \`${failed_command}' "
-
-  if [ $status -eq 1 ]; then
-    echo "failed"
-  else
-    echo "failed with status $status"
-  fi
-}
-
-bats_frame_lineno() {
-  local frame="$1"
-  local lineno="${frame%% *}"
-  echo "$lineno"
-}
-
-bats_frame_function() {
-  local frame="$1"
-  local rest="${frame#* }"
-  local fn="${rest%% *}"
-  echo "$fn"
-}
-
-bats_frame_filename() {
-  local frame="$1"
-  local rest="${frame#* }"
-  local filename="${rest#* }"
-
-  if [ "$filename" = "$BATS_TEST_SOURCE" ]; then
-    echo "$BATS_TEST_FILENAME"
-  else
-    echo "$filename"
-  fi
-}
-
-bats_extract_line() {
-  local filename="$1"
-  local lineno="$2"
-  sed -n "${lineno}p" "$filename"
-}
-
-bats_strip_string() {
-  local string="$1"
-  printf "%s" "$string" | sed -e "s/^[ "$'\t'"]*//" -e "s/[ "$'\t'"]*$//"
-}
-
-bats_trim_filename() {
-  local filename="$1"
-  local length="${#BATS_CWD}"
-
-  if [ "${filename:0:length+1}" = "${BATS_CWD}/" ]; then
-    echo "${filename:length+1}"
-  else
-    echo "$filename"
-  fi
-}
-
-bats_debug_trap() {
-  if [ "$BASH_SOURCE" != "$1" ]; then
-    bats_capture_stack_trace
-  fi
-}
-
-bats_error_trap() {
-  BATS_ERROR_STATUS="$?"
-  BATS_ERROR_STACK_TRACE=( "${BATS_PREVIOUS_STACK_TRACE[@]}" )
-  trap - debug
-}
-
-bats_teardown_trap() {
-  trap "bats_exit_trap" exit
-  local status=0
-  teardown >>"$BATS_OUT" 2>&1 || status="$?"
-
-  if [ $status -eq 0 ]; then
-    BATS_TEARDOWN_COMPLETED=1
-  elif [ -n "$BATS_TEST_COMPLETED" ]; then
-    BATS_ERROR_STATUS="$status"
-    BATS_ERROR_STACK_TRACE=( "${BATS_CURRENT_STACK_TRACE[@]}" )
-  fi
-
-  bats_exit_trap
-}
-
-bats_exit_trap() {
-  local status
-  local skipped
-  trap - err exit
-
-  skipped=""
-  if [ -n "$BATS_TEST_SKIPPED" ]; then
-    skipped=" # skip"
-    if [ "1" != "$BATS_TEST_SKIPPED" ]; then
-      skipped+=" ($BATS_TEST_SKIPPED)"
-    fi
-  fi
-
-  if [ -z "$BATS_TEST_COMPLETED" ] || [ -z "$BATS_TEARDOWN_COMPLETED" ]; then
-    echo "not ok $BATS_TEST_NUMBER $BATS_TEST_DESCRIPTION" >&3
-    bats_print_stack_trace "${BATS_ERROR_STACK_TRACE[@]}" >&3
-    bats_print_failed_command "${BATS_ERROR_STACK_TRACE[${#BATS_ERROR_STACK_TRACE[@]}-1]}" "$BATS_ERROR_STATUS" >&3
-    sed -e "s/^/# /" < "$BATS_OUT" >&3
-    status=1
-  else
-    echo "ok ${BATS_TEST_NUMBER}${skipped} ${BATS_TEST_DESCRIPTION}" >&3
-    status=0
-  fi
-
-  rm -f "$BATS_OUT"
-  exit "$status"
-}
-
-bats_perform_tests() {
-  echo "1..$#"
-  test_number=1
-  status=0
-  for test_name in "$@"; do
-    "$0" $BATS_EXTENDED_SYNTAX "$BATS_TEST_FILENAME" "$test_name" "$test_number" || status=1
-    let test_number+=1
-  done
-  exit "$status"
-}
-
-bats_perform_test() {
-  BATS_TEST_NAME="$1"
-  if [ "$(type -t "$BATS_TEST_NAME" || true)" = "function" ]; then
-    BATS_TEST_NUMBER="$2"
-    if [ -z "$BATS_TEST_NUMBER" ]; then
-      echo "1..1"
-      BATS_TEST_NUMBER="1"
-    fi
-
-    BATS_TEST_COMPLETED=""
-    BATS_TEARDOWN_COMPLETED=""
-    trap "bats_debug_trap \"\$BASH_SOURCE\"" debug
-    trap "bats_error_trap" err
-    trap "bats_teardown_trap" exit
-    "$BATS_TEST_NAME" >>"$BATS_OUT" 2>&1
-    BATS_TEST_COMPLETED=1
-
-  else
-    echo "bats: unknown test name \`$BATS_TEST_NAME'" >&2
-    exit 1
-  fi
-}
-
-if [ -z "$TMPDIR" ]; then
-  BATS_TMPDIR="/tmp"
-else
-  BATS_TMPDIR="${TMPDIR%/}"
-fi
-
-BATS_TMPNAME="$BATS_TMPDIR/bats.$$"
-BATS_PARENT_TMPNAME="$BATS_TMPDIR/bats.$PPID"
-BATS_OUT="${BATS_TMPNAME}.out"
-
-bats_preprocess_source() {
-  BATS_TEST_SOURCE="${BATS_TMPNAME}.src"
-  { tr -d '\r' < "$BATS_TEST_FILENAME"; echo; } | bats-preprocess > "$BATS_TEST_SOURCE"
-  trap "bats_cleanup_preprocessed_source" err exit
-  trap "bats_cleanup_preprocessed_source; exit 1" int
-}
-
-bats_cleanup_preprocessed_source() {
-  rm -f "$BATS_TEST_SOURCE"
-}
-
-bats_evaluate_preprocessed_source() {
-  if [ -z "$BATS_TEST_SOURCE" ]; then
-    BATS_TEST_SOURCE="${BATS_PARENT_TMPNAME}.src"
-  fi
-  source "$BATS_TEST_SOURCE"
-}
-
-exec 3<&1
-
-if [ "$#" -eq 0 ]; then
-  bats_preprocess_source
-  bats_evaluate_preprocessed_source
-
-  if [ -n "$BATS_COUNT_ONLY" ]; then
-    echo "${#BATS_TEST_NAMES[@]}"
-  else
-    bats_perform_tests "${BATS_TEST_NAMES[@]}"
-  fi
-else
-  bats_evaluate_preprocessed_source
-  bats_perform_test "$@"
-fi
diff --git a/test/bats/bats-format-tap-stream b/test/bats/bats-format-tap-stream
deleted file mode 100755
index 614768f4..00000000
--- a/test/bats/bats-format-tap-stream
+++ /dev/null
@@ -1,165 +0,0 @@
-#!/usr/bin/env bash
-set -e
-
-# Just stream the TAP output (sans extended syntax) if tput is missing
-command -v tput >/dev/null || exec grep -v "^begin "
-
-header_pattern='[0-9]+\.\.[0-9]+'
-IFS= read -r header
-
-if [[ "$header" =~ $header_pattern ]]; then
-  count="${header:3}"
-  index=0
-  failures=0
-  skipped=0
-  name=""
-  count_column_width=$(( ${#count} * 2 + 2 ))
-else
-  # If the first line isn't a TAP plan, print it and pass the rest through
-  printf "%s\n" "$header"
-  exec cat
-fi
-
-update_screen_width() {
-  screen_width="$(tput cols)"
-  count_column_left=$(( $screen_width - $count_column_width ))
-}
-
-trap update_screen_width WINCH
-update_screen_width
-
-begin() {
-  go_to_column 0
-  printf_with_truncation $(( $count_column_left - 1 )) "   %s" "$name"
-  clear_to_end_of_line
-  go_to_column $count_column_left
-  printf "%${#count}s/${count}" "$index"
-  go_to_column 1
-}
-
-pass() {
-  go_to_column 0
-  printf " ✓ %s" "$name"
-  advance
-}
-
-skip() {
-  local reason="$1"
-  [ -z "$reason" ] || reason=": $reason"
-  go_to_column 0
-  printf " - %s (skipped%s)" "$name" "$reason"
-  advance
-}
-
-fail() {
-  go_to_column 0
-  set_color 1 bold
-  printf " ✗ %s" "$name"
-  advance
-}
-
-log() {
-  set_color 1
-  printf "   %s\n" "$1"
-  clear_color
-}
-
-summary() {
-  printf "\n%d test%s" "$count" "$(plural "$count")"
-
-  printf ", %d failure%s" "$failures" "$(plural "$failures")"
-
-  if [ "$skipped" -gt 0 ]; then
-    printf ", %d skipped" "$skipped"
-  fi
-
-  printf "\n"
-}
-
-printf_with_truncation() {
-  local width="$1"
-  shift
-  local string="$(printf "$@")"
-
-  if [ "${#string}" -gt "$width" ]; then
-    printf "%s..." "${string:0:$(( $width - 4 ))}"
-  else
-    printf "%s" "$string"
-  fi
-}
-
-go_to_column() {
-  local column="$1"
-  printf "\x1B[%dG" $(( $column + 1 ))
-}
-
-clear_to_end_of_line() {
-  printf "\x1B[K"
-}
-
-advance() {
-  clear_to_end_of_line
-  echo
-  clear_color
-}
-
-set_color() {
-  local color="$1"
-  local weight="$2"
-  printf "\x1B[%d;%dm" $(( 30 + $color )) "$( [ "$weight" = "bold" ] && echo 1 || echo 22 )"
-}
-
-clear_color() {
-  printf "\x1B[0m"
-}
-
-plural() {
-  [ "$1" -eq 1 ] || echo "s"
-}
-
-_buffer=""
-
-buffer() {
-  _buffer="${_buffer}$("$@")"
-}
-
-flush() {
-  printf "%s" "$_buffer"
-  _buffer=""
-}
-
-finish() {
-  flush
-  printf "\n"
-}
-
-trap finish EXIT
-
-while IFS= read -r line; do
-  case "$line" in
-  "begin "* )
-    let index+=1
-    name="${line#* $index }"
-    buffer begin
-    flush
-    ;;
-  "ok "* )
-    skip_expr="ok $index # skip (\(([^)]*)\))?"
-    if [[ "$line" =~ $skip_expr ]]; then
-      let skipped+=1
-      buffer skip "${BASH_REMATCH[2]}"
-    else
-      buffer pass
-    fi
-    ;;
-  "not ok "* )
-    let failures+=1
-    buffer fail
-    ;;
-  "# "* )
-    buffer log "${line:2}"
-    ;;
-  esac
-done
-
-buffer summary
diff --git a/test/bats/bats-preprocess b/test/bats/bats-preprocess
deleted file mode 100755
index 04297ed0..00000000
--- a/test/bats/bats-preprocess
+++ /dev/null
@@ -1,52 +0,0 @@
-#!/usr/bin/env bash
-set -e
-
-encode_name() {
-  local name="$1"
-  local result="test_"
-
-  if [[ ! "$name" =~ [^[:alnum:]\ _-] ]]; then
-    name="${name//_/-5f}"
-    name="${name//-/-2d}"
-    name="${name// /_}"
-    result+="$name"
-  else
-    local length="${#name}"
-    local char i
-
-    for ((i=0; i<length; i++)); do
-      char="${name:$i:1}"
-      if [ "$char" = " " ]; then
-        result+="_"
-      elif [[ "$char" =~ [[:alnum:]] ]]; then
-        result+="$char"
-      else
-        result+="$(printf -- "-%02x" \'"$char")"
-      fi
-    done
-  fi
-
-  echo "$result"
-}
-
-tests=()
-index=0
-pattern='^ *@test  *([^ ].*)  *\{ *(.*)$'
-
-while IFS= read -r line; do
-  let index+=1
-  if [[ "$line" =~ $pattern ]]; then
-    quoted_name="${BASH_REMATCH[1]}"
-    body="${BASH_REMATCH[2]}"
-    name="$(eval echo "$quoted_name")"
-    encoded_name="$(encode_name "$name")"
-    tests["${#tests[@]}"]="$encoded_name"
-    echo "${encoded_name}() { bats_test_begin ${quoted_name} ${index}; ${body}"
-  else
-    printf "%s\n" "$line"
-  fi
-done
-
-for test_name in "${tests[@]}"; do
-  echo "bats_test_function ${test_name}"
-done
diff --git a/test/test_helper/bats-assert b/test/test_helper/bats-assert
new file mode 160000
index 00000000..9f88b420
--- /dev/null
+++ b/test/test_helper/bats-assert
@@ -0,0 +1 @@
+Subproject commit 9f88b4207da750093baabc4e3f41bf68f0dd3630
diff --git a/test/test_helper/bats-support b/test/test_helper/bats-support
new file mode 160000
index 00000000..004e7076
--- /dev/null
+++ b/test/test_helper/bats-support
@@ -0,0 +1 @@
+Subproject commit 004e707638eedd62e0481e8cdc9223ad471f12ee
diff --git a/test/tests.bats b/test/tests.bats
index 955931c7..0e0fdebd 100644
--- a/test/tests.bats
+++ b/test/tests.bats
@@ -1,10 +1,12 @@
+load 'test_helper/bats-support/load'
+load 'test_helper/bats-assert/load'
 #
 # configuration checks
 #
 
 @test "checking configuration: hostname/domainname" {
   run docker run `docker inspect --format '{{ .Config.Image }}' mail`
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 #
@@ -13,62 +15,62 @@
 
 @test "checking process: postfix" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/lib/postfix/master'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: clamd" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/clamd'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: new" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/amavisd-new'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: opendkim" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/opendkim'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: opendmarc" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/opendmarc'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: fail2ban (disabled in default configuration)" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/bin/python /usr/bin/fail2ban-server'"
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking process: fail2ban (fail2ban server enabled)" {
   run docker exec mail_fail2ban /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/bin/python /usr/bin/fail2ban-server'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: fetchmail (disabled in default configuration)" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/bin/fetchmail'"
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking process: fetchmail (fetchmail server enabled)" {
   run docker exec mail_fetchmail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/bin/fetchmail'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: clamav (clamav disabled by ENABLED_CLAMAV=0)" {
   run docker exec mail_disabled_clamav_spamassassin /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/clamd'"
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking process: saslauthd (saslauthd server enabled)" {
   run docker exec mail_with_ldap /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/saslauthd'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: saslauthd (saslauthd server enabled)" {
   run docker exec mail_with_imap /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/saslauthd'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -77,22 +79,22 @@
 
 @test "checking process: dovecot imaplogin (enabled in default configuration)" {
   run docker exec mail /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/dovecot'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking process: dovecot imaplogin (disabled using SMTP_ONLY)" {
   run docker exec mail_smtponly /bin/bash -c "ps aux --forest | grep -v grep | grep '/usr/sbin/dovecot'"
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking imap: server is ready with STARTTLS" {
   run docker exec mail /bin/bash -c "nc -w 2 0.0.0.0 143 | grep '* OK' | grep 'STARTTLS' | grep 'ready'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking imap: authentication works" {
   run docker exec mail /bin/sh -c "nc -w 1 0.0.0.0 143 < /tmp/docker-mailserver-test/auth/imap-auth.txt"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -101,12 +103,12 @@
 
 @test "checking pop: server is ready" {
   run docker exec mail_pop3 /bin/bash -c "nc -w 1 0.0.0.0 110 | grep '+OK'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking pop: authentication works" {
   run docker exec mail_pop3 /bin/sh -c "nc -w 1 0.0.0.0 110 < /tmp/docker-mailserver-test/auth/pop3-auth.txt"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -115,17 +117,17 @@
 
 @test "checking sasl: doveadm auth test works with good password" {
   run docker exec mail /bin/sh -c "doveadm auth test -x service=smtp user2@otherdomain.tld mypassword | grep 'auth succeeded'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking sasl: doveadm auth test fails with bad password" {
   run docker exec mail /bin/sh -c "doveadm auth test -x service=smtp user2@otherdomain.tld BADPASSWORD | grep 'auth failed'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking sasl: sasl_passwd exists" {
   run docker exec mail [ -f /etc/postfix/sasl_passwd ]
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -134,8 +136,8 @@
 
 @test "checking logs: mail related logs should be located in a subdirectory" {
   run docker exec mail /bin/sh -c "ls -1 /var/log/mail/ | grep -E 'clamav|freshclam|mail'|wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 3 ]
+  assert_success
+  assert_output 3
 }
 
 #
@@ -144,76 +146,76 @@
 
 @test "checking smtp: authentication works with good password (plain)" {
   run docker exec mail /bin/sh -c "nc -w 5 0.0.0.0 25 < /tmp/docker-mailserver-test/auth/smtp-auth-plain.txt | grep 'Authentication successful'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking smtp: authentication fails with wrong password (plain)" {
   run docker exec mail /bin/sh -c "nc -w 20 0.0.0.0 25 < /tmp/docker-mailserver-test/auth/smtp-auth-plain-wrong.txt | grep 'authentication failed'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking smtp: authentication works with good password (login)" {
   run docker exec mail /bin/sh -c "nc -w 5 0.0.0.0 25 < /tmp/docker-mailserver-test/auth/smtp-auth-login.txt | grep 'Authentication successful'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking smtp: authentication fails with wrong password (login)" {
   run docker exec mail /bin/sh -c "nc -w 20 0.0.0.0 25 < /tmp/docker-mailserver-test/auth/smtp-auth-login-wrong.txt | grep 'authentication failed'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking smtp: delivers mail to existing account" {
   run docker exec mail /bin/sh -c "grep 'postfix/lmtp' /var/log/mail/mail.log | grep 'status=sent' | grep ' Saved)' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 6 ]
+  assert_success
+  assert_output 6
 }
 
 @test "checking smtp: delivers mail to existing alias" {
   run docker exec mail /bin/sh -c "grep 'to=<user1@localhost.localdomain>, orig_to=<alias1@localhost.localdomain>' /var/log/mail/mail.log | grep 'status=sent' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking smtp: delivers mail to existing catchall" {
   run docker exec mail /bin/sh -c "grep 'to=<user1@localhost.localdomain>, orig_to=<wildcard@localdomain2.com>' /var/log/mail/mail.log | grep 'status=sent' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking smtp: delivers mail to regexp alias" {
   run docker exec mail /bin/sh -c "grep 'to=<user1@localhost.localdomain>, orig_to=<test123@localhost.localdomain>' /var/log/mail/mail.log | grep 'status=sent' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking smtp: user1 should have received 5 mails" {
   run docker exec mail /bin/sh -c "ls -A /var/mail/localhost.localdomain/user1/new | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 5 ]
+  assert_success
+  assert_output 5
 }
 
 @test "checking smtp: rejects mail to unknown user" {
   run docker exec mail /bin/sh -c "grep '<nouser@localhost.localdomain>: Recipient address rejected: User unknown in virtual mailbox table' /var/log/mail/mail.log | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking smtp: redirects mail to external aliases" {
   run docker exec mail /bin/sh -c "grep -- '-> <external1@otherdomain.tld>' /var/log/mail/mail.log | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 2 ]
+  assert_success
+  assert_output 2
 }
 
 @test "checking smtp: rejects spam" {
   run docker exec mail /bin/sh -c "grep 'Blocked SPAM' /var/log/mail/mail.log | grep spam@external.tld | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking smtp: rejects virus" {
   run docker exec mail /bin/sh -c "grep 'Blocked INFECTED' /var/log/mail/mail.log | grep virus@external.tld | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 #
@@ -222,21 +224,21 @@
 
 @test "checking accounts: user accounts" {
   run docker exec mail doveadm user '*'
-  [ "$status" -eq 0 ]
+  assert_success
   [ "${lines[0]}" = "user1@localhost.localdomain" ]
   [ "${lines[1]}" = "user2@otherdomain.tld" ]
 }
 
 @test "checking accounts: user mail folders for user1" {
   run docker exec mail /bin/bash -c "ls -A /var/mail/localhost.localdomain/user1 | grep -E '.Drafts|.Sent|.Trash|cur|new|subscriptions|tmp' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 7 ]
+  assert_success
+  assert_output 7
 }
 
 @test "checking accounts: user mail folders for user2" {
   run docker exec mail /bin/bash -c "ls -A /var/mail/otherdomain.tld/user2 | grep -E '.Drafts|.Sent|.Trash|cur|new|subscriptions|tmp' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 7 ]
+  assert_success
+  assert_output 7
 }
 
 #
@@ -245,7 +247,7 @@
 
 @test "checking postfix: vhost file is correct" {
   run docker exec mail cat /etc/postfix/vhost
-  [ "$status" -eq 0 ]
+  assert_success
   [ "${lines[0]}" = "localdomain2.com" ]
   [ "${lines[1]}" = "localhost.localdomain" ]
   [ "${lines[2]}" = "otherdomain.tld" ]
@@ -253,9 +255,9 @@
 
 @test "checking postfix: main.cf overrides" {
   run docker exec mail grep -q 'max_idle = 600s' /tmp/docker-mailserver/postfix-main.cf
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail grep -q 'readme_directory = /tmp' /tmp/docker-mailserver/postfix-main.cf
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -264,10 +266,10 @@
 
 @test "checking dovecot: config additions" {
   run docker exec mail grep -q 'mail_max_userip_connections = 69' /tmp/docker-mailserver/dovecot.cf
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail /bin/sh -c "doveconf | grep 'mail_max_userip_connections = 69'"
-  [ "$status" -eq 0 ]
-  [ "$output" = 'mail_max_userip_connections = 69' ]
+  assert_success
+  assert_output 'mail_max_userip_connections = 69'
 }
 
 #
@@ -276,30 +278,30 @@
 
 @test "checking spamassassin: should be listed in amavis when enabled" {
   run docker exec mail /bin/sh -c "grep -i 'ANTI-SPAM-SA code' /var/log/mail/mail.log | grep 'NOT loaded'"
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking spamassassin: should not be listed in amavis when disabled" {
   run docker exec mail_disabled_clamav_spamassassin /bin/sh -c "grep -i 'ANTI-SPAM-SA code' /var/log/mail/mail.log | grep 'NOT loaded'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking spamassassin: docker env variables are set correctly (default)" {
   run docker exec mail_pop3 /bin/sh -c "grep '\$sa_tag_level_deflt' /etc/amavis/conf.d/20-debian_defaults | grep '= 2.0'"
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail_pop3 /bin/sh -c "grep '\$sa_tag2_level_deflt' /etc/amavis/conf.d/20-debian_defaults | grep '= 6.31'"
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail_pop3 /bin/sh -c "grep '\$sa_kill_level_deflt' /etc/amavis/conf.d/20-debian_defaults | grep '= 6.31'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking spamassassin: docker env variables are set correctly (custom)" {
   run docker exec mail /bin/sh -c "grep '\$sa_tag_level_deflt' /etc/amavis/conf.d/20-debian_defaults | grep '= 1.0'"
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail /bin/sh -c "grep '\$sa_tag2_level_deflt' /etc/amavis/conf.d/20-debian_defaults | grep '= 2.0'"
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail /bin/sh -c "grep '\$sa_kill_level_deflt' /etc/amavis/conf.d/20-debian_defaults | grep '= 3.0'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -308,17 +310,17 @@
 
 @test "checking clamav: should be listed in amavis when enabled" {
   run docker exec mail grep -i 'Found secondary av scanner ClamAV-clamscan' /var/log/mail/mail.log
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking clamav: should not be listed in amavis when disabled" {
   run docker exec mail_disabled_clamav_spamassassin grep -i 'Found secondary av scanner ClamAV-clamscan' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking clamav: should not be called when disabled" {
   run docker exec mail_disabled_clamav_spamassassin grep -i 'connect to /var/run/clamav/clamd.ctl failed' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 #
@@ -327,14 +329,14 @@
 
 @test "checking opendkim: /etc/opendkim/KeyTable should contain 2 entries" {
   run docker exec mail /bin/sh -c "cat /etc/opendkim/KeyTable | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
 }
 
 @test "checking opendkim: /etc/opendkim/keys/ should contain 2 entries" {
   run docker exec mail /bin/sh -c "ls -l /etc/opendkim/keys/ | grep '^d' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
 }
 
 @test "checking opendkim: generator creates keys, tables and TrustedHosts" {
@@ -344,26 +346,26 @@
     -v "$(pwd)/test/config/postfix-accounts.cf":/tmp/docker-mailserver/postfix-accounts.cf \
     -v "$(pwd)/test/config/postfix-virtual.cf":/tmp/docker-mailserver/postfix-virtual.cf \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'generate-dkim-config | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 6 ]
+  assert_success
+  assert_output 6
   # Check keys for localhost.localdomain
   run docker run --rm \
     -v "$(pwd)/test/config/empty/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'ls -1 /etc/opendkim/keys/localhost.localdomain/ | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
   # Check keys for otherdomain.tld
   run docker run --rm \
     -v "$(pwd)/test/config/empty/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'ls -1 /etc/opendkim/keys/otherdomain.tld | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
   # Check presence of tables and TrustedHosts
   run docker run --rm \
     -v "$(pwd)/test/config/empty/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c "ls -1 etc/opendkim | grep -E 'KeyTable|SigningTable|TrustedHosts|keys'|wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 4 ]
+  assert_success
+  assert_output 4
 }
 
 @test "checking opendkim: generator creates keys, tables and TrustedHosts without postfix-accounts.cf" {
@@ -372,26 +374,26 @@
     -v "$(pwd)/test/config/without-accounts/":/tmp/docker-mailserver/ \
     -v "$(pwd)/test/config/postfix-virtual.cf":/tmp/docker-mailserver/postfix-virtual.cf \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'generate-dkim-config | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 5 ]
+  assert_success
+  assert_output 5
   # Check keys for localhost.localdomain
   run docker run --rm \
     -v "$(pwd)/test/config/without-accounts/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'ls -1 /etc/opendkim/keys/localhost.localdomain/ | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
   # Check keys for otherdomain.tld
   # run docker run --rm \
   #   -v "$(pwd)/test/config/without-accounts/opendkim":/etc/opendkim \
   #   `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'ls -1 /etc/opendkim/keys/otherdomain.tld | wc -l'
-  # [ "$status" -eq 0 ]
+  # assert_success
   # [ "$output" -eq 0 ]
   # Check presence of tables and TrustedHosts
   run docker run --rm \
     -v "$(pwd)/test/config/without-accounts/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c "ls -1 etc/opendkim | grep -E 'KeyTable|SigningTable|TrustedHosts|keys'|wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 4 ]
+  assert_success
+  assert_output 4
 }
 
 @test "checking opendkim: generator creates keys, tables and TrustedHosts without postfix-virtual.cf" {
@@ -400,26 +402,26 @@
     -v "$(pwd)/test/config/without-virtual/":/tmp/docker-mailserver/ \
     -v "$(pwd)/test/config/postfix-accounts.cf":/tmp/docker-mailserver/postfix-accounts.cf \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'generate-dkim-config | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 5 ]
+  assert_success
+  assert_output 5
   # Check keys for localhost.localdomain
   run docker run --rm \
     -v "$(pwd)/test/config/without-virtual/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'ls -1 /etc/opendkim/keys/localhost.localdomain/ | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
   # Check keys for otherdomain.tld
   run docker run --rm \
     -v "$(pwd)/test/config/without-virtual/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'ls -1 /etc/opendkim/keys/otherdomain.tld | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
   # Check presence of tables and TrustedHosts
   run docker run --rm \
     -v "$(pwd)/test/config/without-virtual/opendkim":/etc/opendkim \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c "ls -1 etc/opendkim | grep -E 'KeyTable|SigningTable|TrustedHosts|keys'|wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 4 ]
+  assert_success
+  assert_output 4
 }
 
 #
@@ -428,53 +430,53 @@
 
 @test "checking ssl: generated default cert works correctly" {
   run docker exec mail /bin/sh -c "timeout 1 openssl s_client -connect 0.0.0.0:587 -starttls smtp -CApath /etc/ssl/certs/ | grep 'Verify return code: 0 (ok)'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking ssl: lets-encrypt-x3-cross-signed.pem is installed" {
   run docker exec mail grep 'BEGIN CERTIFICATE' /etc/ssl/certs/lets-encrypt-x3-cross-signed.pem
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking ssl: letsencrypt configuration is correct" {
   run docker exec mail_pop3 /bin/sh -c 'grep -ir "/etc/letsencrypt/live/mail.my-domain.com/" /etc/postfix/main.cf | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
   run docker exec mail_pop3 /bin/sh -c 'grep -ir "/etc/letsencrypt/live/mail.my-domain.com/" /etc/dovecot/conf.d/10-ssl.conf | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 2 ]
+  assert_success
+  assert_output 2
 }
 
 @test "checking ssl: letsencrypt cert works correctly" {
   run docker exec mail_pop3 /bin/sh -c "timeout 1 openssl s_client -connect 0.0.0.0:587 -starttls smtp -CApath /etc/ssl/certs/ | grep 'Verify return code: 10 (certificate has expired)'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking ssl: manual configuration is correct" {
   run docker exec mail_manual_ssl /bin/sh -c 'grep -ir "/etc/postfix/ssl/cert" /etc/postfix/main.cf | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
   run docker exec mail_manual_ssl /bin/sh -c 'grep -ir "/etc/postfix/ssl/cert" /etc/dovecot/conf.d/10-ssl.conf | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
   run docker exec mail_manual_ssl /bin/sh -c 'grep -ir "/etc/postfix/ssl/key" /etc/postfix/main.cf | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
   run docker exec mail_manual_ssl /bin/sh -c 'grep -ir "/etc/postfix/ssl/key" /etc/dovecot/conf.d/10-ssl.conf | wc -l'
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking ssl: manual configuration copied files correctly " {
   run docker exec mail_manual_ssl /bin/sh -c 'cmp -s /etc/postfix/ssl/cert /tmp/docker-mailserver/letsencrypt/mail.my-domain.com/fullchain.pem'
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail_manual_ssl /bin/sh -c 'cmp -s /etc/postfix/ssl/key /tmp/docker-mailserver/letsencrypt/mail.my-domain.com/privkey.pem'
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking ssl: manual cert works correctly" {
   run docker exec mail_manual_ssl /bin/sh -c "timeout 1 openssl s_client -connect 0.0.0.0:587 -starttls smtp -CApath /etc/ssl/certs/ | grep 'Verify return code: 10 (certificate has expired)'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -483,9 +485,9 @@
 
 @test "checking fail2ban: localhost is not banned because ignored" {
   run docker exec mail_fail2ban /bin/sh -c "fail2ban-client status postfix-sasl | grep 'IP list:.*127.0.0.1'"
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail_fail2ban /bin/sh -c "grep 'ignoreip = 127.0.0.1/8' /etc/fail2ban/jail.conf"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking fail2ban: fail2ban-jail.cf overrides" {
@@ -493,13 +495,13 @@
 
   for FILTER in "${FILTERS[@]}"; do
     run docker exec mail_fail2ban /bin/sh -c "fail2ban-client get $FILTER bantime"
-    [ "$output" = 1234 ]
+    assert_output 1234
 
     run docker exec mail_fail2ban /bin/sh -c "fail2ban-client get $FILTER findtime"
-    [ "$output" = 321 ]
+    assert_output 321
 
     run docker exec mail_fail2ban /bin/sh -c "fail2ban-client get $FILTER maxretry"
-    [ "$output" = 2 ]
+    assert_output 2
   done
 }
 
@@ -519,11 +521,11 @@
   FAIL_AUTH_MAILER_IP=$(docker inspect --format '{{ .NetworkSettings.IPAddress }}' fail-auth-mailer)
 
   run docker exec mail_fail2ban /bin/sh -c "fail2ban-client status postfix-sasl | grep '$FAIL_AUTH_MAILER_IP'"
-  [ "$status" -eq 0 ]
+  assert_success
 
   # Checking that FAIL_AUTH_MAILER_IP is banned by iptables
   run docker exec mail_fail2ban /bin/sh -c "iptables -L f2b-postfix-sasl -n | grep REJECT | grep '$FAIL_AUTH_MAILER_IP'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking fail2ban: unban ip works" {
@@ -534,11 +536,11 @@
   sleep 5
 
   run docker exec mail_fail2ban /bin/sh -c "fail2ban-client status postfix-sasl | grep 'IP list:.*$FAIL_AUTH_MAILER_IP'"
-  [ "$status" -eq 1 ]
+  assert_failure
 
   # Checking that FAIL_AUTH_MAILER_IP is unbanned by iptables
   run docker exec mail_fail2ban /bin/sh -c "iptables -L f2b-postfix-sasl -n | grep REJECT | grep '$FAIL_AUTH_MAILER_IP'"
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 #
@@ -547,12 +549,12 @@
 
 @test "checking fetchmail: gerneral options in fetchmailrc are loaded" {
   run docker exec mail_fetchmail grep 'set syslog' /etc/fetchmailrc
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking fetchmail: fetchmail.cf is loaded" {
   run docker exec mail_fetchmail grep 'pop3.example.com' /etc/fetchmailrc
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -561,74 +563,74 @@
 
 @test "checking system: freshclam cron is enabled" {
   run docker exec mail bash -c "crontab -l | grep '/usr/bin/freshclam'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking amavis: virusmail wiper cron exists" {
   run docker exec mail bash -c "crontab -l | grep '/var/lib/amavis/virusmails/'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking amavis: VIRUSMAILS_DELETE_DELAY override works as expected" {
   run docker run -ti --rm -e VIRUSMAILS_DELETE_DELAY=2 `docker inspect --format '{{ .Config.Image }}' mail` /bin/bash -c 'echo $VIRUSMAILS_DELETE_DELAY | grep 2'
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking amavis: old virusmail is wipped by cron" {
   docker exec mail bash -c 'touch -d "`date --date=2000-01-01`" /var/lib/amavis/virusmails/should-be-deleted'
   run docker exec -ti mail bash -c 'find /var/lib/amavis/virusmails/ -type f -mtime +$VIRUSMAILS_DELETE_DELAY -delete'
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail bash -c 'ls -la /var/lib/amavis/virusmails/ | grep should-be-deleted'
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking amavis: recent virusmail is not wipped by cron" {
   docker exec mail bash -c 'touch -d "`date`"  /var/lib/amavis/virusmails/should-not-be-deleted'
   run docker exec -ti mail bash -c 'find /var/lib/amavis/virusmails/ -type f -mtime +$VIRUSMAILS_DELETE_DELAY -delete'
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail bash -c 'ls -la /var/lib/amavis/virusmails/ | grep should-not-be-deleted'
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking system: /var/log/mail/mail.log is error free" {
   run docker exec mail grep 'non-null host address bits in' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail grep 'mail system configuration error' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail grep ': error:' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail grep -i 'is not writable' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail grep -i 'permission denied' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail grep -i '(!)connect' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail_pop3 grep 'non-null host address bits in' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
   run docker exec mail_pop3 grep ': error:' /var/log/mail/mail.log
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking system: /var/log/auth.log is error free" {
   run docker exec mail grep 'Unable to open env file: /etc/default/locale' /var/log/auth.log
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 @test "checking system: sets the server fqdn" {
   run docker exec mail hostname
-  [ "$status" -eq 0 ]
-  [ "$output" = "mail.my-domain.com" ]
+  assert_success
+  assert_output "mail.my-domain.com"
 }
 
 @test "checking system: sets the server domain name in /etc/mailname" {
   run docker exec mail cat /etc/mailname
-  [ "$status" -eq 0 ]
-  [ "$output" = "my-domain.com" ]
+  assert_success
+  assert_output "my-domain.com"
 }
 
 @test "checking system: postfix should not log to syslog" {
   run docker exec mail grep 'postfix' /var/log/syslog
-  [ "$status" -eq 1 ]
+  assert_failure
 }
 
 #
@@ -637,18 +639,18 @@
 
 @test "checking sieve: user1 should have received 1 email in folder INBOX.spam" {
   run docker exec mail /bin/sh -c "ls -A /var/mail/localhost.localdomain/user1/.INBOX.spam/new | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" = 1 ]
+  assert_success
+  assert_output 1
 }
 
 @test "checking manage sieve: server is ready when ENABLE_MANAGESIEVE has been set" {
   run docker exec mail /bin/bash -c "nc -z 0.0.0.0 4190"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking manage sieve: disabled per default" {
   run docker exec mail_pop3 /bin/bash -c "nc -z 0.0.0.0 4190"
-  [ "$status" -ne 0 ]
+  assert_failure
 }
 
 #
@@ -659,7 +661,7 @@
   docker exec mail /bin/sh -c "addmailuser user3@domain.tld mypassword"
 
   run docker exec mail /bin/sh -c "grep '^user3@domain\.tld|' -i /tmp/docker-mailserver/postfix-accounts.cf"
-  [ "$status" -eq 0 ]
+  assert_success
   [ ! -z "$output" ]
 }
 
@@ -667,7 +669,7 @@
   docker exec mail /bin/sh -c "addmailuser auser3@domain.tld mypassword"
 
   run docker exec mail /bin/sh -c "grep '^auser3@domain\.tld|' -i /tmp/docker-mailserver/postfix-accounts.cf"
-  [ "$status" -eq 0 ]
+  assert_success
   [ ! -z "$output" ]
 }
 
@@ -675,7 +677,7 @@
   docker exec mail /bin/sh -c "addmailuser a.ser3@domain.tld mypassword"
 
   run docker exec mail /bin/sh -c "grep '^a\.ser3@domain\.tld|' -i /tmp/docker-mailserver/postfix-accounts.cf"
-  [ "$status" -eq 0 ]
+  assert_success
   [ ! -z "$output" ]
 }
 
@@ -683,11 +685,11 @@
   docker exec mail /bin/sh -c "delmailuser user3@domain.tld"
 
   run docker exec mail /bin/sh -c "grep '^user3@domain\.tld' -i /tmp/docker-mailserver/postfix-accounts.cf"
-  [ "$status" -eq 1 ]
+  assert_failure
   [ -z "$output" ]
 
   run docker exec mail /bin/sh -c "grep '^auser3@domain\.tld' -i /tmp/docker-mailserver/postfix-accounts.cf"
-  [ "$status" -eq 0 ]
+  assert_success
   [ ! -z "$output" ]
 }
 
@@ -708,21 +710,21 @@
 
   docker exec mail /bin/sh -c "delmailuser auser3@domain.tld"
 
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 
 @test "checking accounts: listmailuser" {
   run docker exec mail /bin/sh -c "listmailuser | head -n 1"
-  [ "$status" -eq 0 ]
-  [ "$output" = user1@localhost.localdomain ]
+  assert_success
+  assert_output 'user1@localhost.localdomain'
 }
 
 @test "checking accounts: no error is generated when deleting a user if /tmp/docker-mailserver/postfix-accounts.cf is missing" {
   run docker run --rm \
     -v "$(pwd)/test/config/without-accounts/":/tmp/docker-mailserver/ \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'delmailuser user3@domain.tld'
-  [ "$status" -eq 0 ]
+  assert_success
   [ -z "$output" ]
 }
 
@@ -730,11 +732,11 @@
   run docker run --rm \
     -v "$(pwd)/test/config/without-accounts/":/tmp/docker-mailserver/ \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'addmailuser user3@domain.tld mypassword'
-  [ "$status" -eq 0 ]
+  assert_success
   run docker run --rm \
     -v "$(pwd)/test/config/without-accounts/":/tmp/docker-mailserver/ \
     `docker inspect --format '{{ .Config.Image }}' mail` /bin/sh -c 'grep user3@domain.tld -i /tmp/docker-mailserver/postfix-accounts.cf'
-  [ "$status" -eq 0 ]
+  assert_success
   [ ! -z "$output" ]
 }
 
@@ -744,21 +746,21 @@
 
 @test "checking PERMIT_DOCKER: can get container ip" {
   run docker exec mail /bin/sh -c "ip addr show eth0 | grep 'inet ' | sed 's/[^0-9\.\/]*//g' | cut -d '/' -f 1 | egrep '[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking PERMIT_DOCKER: opendmarc/opendkim config" {
   run docker exec mail_smtponly /bin/sh -c "cat /etc/opendmarc/ignore.hosts | grep '172.16.0.0/12'"
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail_smtponly /bin/sh -c "cat /etc/opendkim/TrustedHosts | grep '172.16.0.0/12'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking PERMIT_DOCKER: my network value" {
   run docker exec mail /bin/sh -c "postconf | grep '^mynetworks =' | egrep '[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.0\.0/16'"
-  [ "$status" -eq 0 ]
+  assert_success
   run docker exec mail_pop3 /bin/sh -c "postconf | grep '^mynetworks =' | egrep '[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}\.[[:digit:]]{1,3}/32'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -767,8 +769,8 @@
 
 @test "checking amavis: config overrides" {
   run docker exec mail /bin/sh -c "grep 'Test Verification' /etc/amavis/conf.d/50-user | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
 }
 
 #
@@ -778,25 +780,25 @@
 # CLI interface
 @test "checking setup.sh: Without arguments: status 1, show help text" {
   run ./setup.sh
-  [ "$status" -eq 1 ]
+  assert_failure
   [ "${lines[0]}" = "Usage: ./setup.sh [-i IMAGE_NAME] [-c CONTAINER_NAME] <subcommand> <subcommand> [args]" ]
 }
 @test "checking setup.sh: Wrong arguments" {
   run ./setup.sh lol troll
-  [ "$status" -eq 1 ]
+  assert_failure
   [ "${lines[0]}" = "Usage: ./setup.sh [-i IMAGE_NAME] [-c CONTAINER_NAME] <subcommand> <subcommand> [args]" ]
 }
 
 # email
 @test "checking setup.sh: setup.sh email add " {
   run ./setup.sh -c mail email add lorem@impsum.org dolorsit
-  [ "$status" -eq 0 ]
+  assert_success
   value=$(cat ./config/postfix-accounts.cf | grep lorem@impsum.org | awk -F '|' '{print $1}')
   [ "$value" = "lorem@impsum.org" ]
 }
 @test "checking setup.sh: setup.sh email list" {
   run ./setup.sh -c mail email list
-  [ "$status" -eq 0 ]
+  assert_success
 }
 @test "checking setup.sh: setup.sh email update" {
   initialpass=$(cat ./config/postfix-accounts.cf | grep lorem@impsum.org | awk -F '|' '{print $2}')
@@ -807,11 +809,11 @@
     else
       status="1"
     fi
-  [ "$status" -eq 0 ]
+  assert_success
 }
 @test "checking setup.sh: setup.sh email del" {
   run ./setup.sh -c mail email del lorem@impsum.org
-  [ "$status" -eq 0 ]
+  assert_success
   run value=$(cat ./config/postfix-accounts.cf | grep lorem@impsum.org)
   [ -z "$value" ]
 }
@@ -819,12 +821,12 @@
 # config
 @test "checking setup.sh: setup.sh config dkim" {
   run ./setup.sh -c mail config dkim
-  [ "$status" -eq 0 ]
+  assert_success
 }
 # TODO: To create a test generate-ssl-certificate must be non interactive
 #@test "checking setup.sh: setup.sh config ssl" {
 #  run ./setup.sh -c mail_ssl config ssl
-#  [ "$status" -eq 0 ]
+#  assert_success
 #}
 
 # debug
@@ -836,13 +838,13 @@
 }
 @test "checking setup.sh: setup.sh debug inspect" {
   run ./setup.sh -c mail debug inspect
-  [ "$status" -eq 0 ]
+  assert_success
   [ "${lines[0]}" = "Image: tvial/docker-mailserver:testing" ]
   [ "${lines[1]}" = "Container: mail" ]
 }
 @test "checking setup.sh: setup.sh debug login ls" {
   run ./setup.sh -c mail debug login ls
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -852,39 +854,39 @@
 # postfix
 @test "checking postfix: ldap lookup works correctly" {
   run docker exec mail_with_ldap /bin/sh -c "postmap -q some.user@localhost.localdomain ldap:/etc/postfix/ldap-users.cf"
-  [ "$status" -eq 0 ]
-  [ "$output" = "some.user@localhost.localdomain" ]
+  assert_success
+  assert_output "some.user@localhost.localdomain"
   run docker exec mail_with_ldap /bin/sh -c "postmap -q postmaster@localhost.localdomain ldap:/etc/postfix/ldap-aliases.cf"
-  [ "$status" -eq 0 ]
-  [ "$output" = "some.user@localhost.localdomain" ]
+  assert_success
+  assert_output "some.user@localhost.localdomain"
   run docker exec mail_with_ldap /bin/sh -c "postmap -q employees@localhost.localdomain ldap:/etc/postfix/ldap-groups.cf"
-  [ "$status" -eq 0 ]
-  [ "$output" = "some.user@localhost.localdomain" ]
+  assert_success
+  assert_output "some.user@localhost.localdomain"
 }
 
 # dovecot
 @test "checking dovecot: ldap imap connection and authentication works" {
   run docker exec mail_with_ldap /bin/sh -c "nc -w 1 0.0.0.0 143 < /tmp/docker-mailserver-test/auth/imap-ldap-auth.txt"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking dovecot: mail delivery works" {
   run docker exec mail_with_ldap /bin/sh -c "sendmail -f user@external.tld some.user@localhost.localdomain < /tmp/docker-mailserver-test/email-templates/test-email.txt"
   sleep 10
   run docker exec mail_with_ldap /bin/sh -c "ls -A /var/mail/localhost.localdomain/some.user/new | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
 }
 
 # saslauthd
 @test "checking saslauthd: sasl ldap authentication works" {
   run docker exec mail_with_ldap bash -c "testsaslauthd -u some.user -p secret"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking saslauthd: ldap smtp authentication" {
   run docker exec mail_with_ldap /bin/sh -c "nc -w 5 0.0.0.0 25 < /tmp/docker-mailserver-test/auth/sasl-ldap-smtp-auth.txt | grep 'Authentication successful'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -894,18 +896,18 @@
 # dovecot
 @test "checking dovecot: ldap rimap connection and authentication works" {
   run docker exec mail_with_imap /bin/sh -c "nc -w 1 0.0.0.0 143 < /tmp/docker-mailserver-test/auth/imap-auth.txt"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 # saslauthd
 @test "checking saslauthd: sasl rimap authentication works" {
   run docker exec mail_with_imap bash -c "testsaslauthd -u user1@localhost.localdomain -p mypassword"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 @test "checking saslauthd: rimap smtp authentication" {
   run docker exec mail_with_imap /bin/sh -c "nc -w 5 0.0.0.0 25 < /tmp/docker-mailserver-test/auth/smtp-auth-login.txt | grep 'Authentication successful'"
-  [ "$status" -eq 0 ]
+  assert_success
 }
 
 #
@@ -913,11 +915,11 @@
 #
 @test "checking postfix-lmtp: virtual_transport config is set" {
     run docker exec mail_lmtp_ip /bin/sh -c "grep 'virtual_transport = lmtp:127.0.0.1:24' /etc/postfix/main.cf"
-    [ "$status" -eq 0 ]
+    assert_success
 }
 
 @test "checking postfix-lmtp: delivers mail to existing account" {
   run docker exec mail_lmtp_ip /bin/sh -c "grep 'postfix/lmtp' /var/log/mail/mail.log | grep 'status=sent' | grep ' Saved)' | wc -l"
-  [ "$status" -eq 0 ]
-  [ "$output" -eq 1 ]
+  assert_success
+  assert_output 1
 }