midTest

#!/usr/bin/env bash
set -u

# consider making it possible to specify these from command line
  interpreter=./gospel
  midTestExt=mid.sh
  midTestDir=tests
  
passes=0
failures=0

# Run Gospel interpreter
#
# arg 1: code to execute (piped in) with some basic wrapping -- last statement is printed
# arg 2 to n: command line arguments to the interpreter
interpret() {
  local code="$1"; shift
  set -e
  interpreterOutput="$(echo "(${code}) print. exit" | "$interpreter" "$@")"
  set +e
}

# Assertions

  # Equal assertion
  # 
  # arg 1: code to execute
  # arg 2: output you expect it to generate
  # arg 3 to n: command line arguments to the interpreter
  eq () {
    local code="$1"; shift
    local expectation="> $1"; shift
    interpret "$code" "$@"
    if [ "$interpreterOutput" = "$expectation" ]; then
      let passes++
      return 0
    fi
    echo "'$code' expected '$expectation' got '$interpreterOutput' in $midTest"
    let failures++
    return 1
  }

# Execute any number of file in the test dir
# args: File should be named without the mid-test extension defined in $midTestExt
#       dir starts from $midTestDir
runMid () {
  local status=0
  while [ $# -gt 0 ]; do
    # these vars may also be accessed by the mid-test itself or eq()
    local midTest="$1" 
    local midTestPath="$midTestDir/$midTest.$midTestExt"
    if [ -r "$midTestPath" ]; then
      source "$midTestPath"
    else
      # will continue to try any others specified
      echo "Couldn't find mid-test $midTest to load at $midTestPath" 1>&2
      status=1
    fi
    shift
  done
  return $status
}

# Prints a report of all the tests executed
report () {
  if [ $failures -gt 0 ]; then
    echo
  fi
  echo "$(expr $passes + $failures) test executed. $passes pass(es), $failures failure(s)"
}

# Run multiple mid-test specified at the time of invoking this script or by discoving all 
# the ones available in $midTestDir that can be executed.
go () {
  if [ $# -eq 0 ]; then # all tests in dir
    for midTestPath in "$midTestDir"/*."$midTestExt"; do
      midTestWithExt="$(basename "$midTestPath")"
      midTest="${midTestWithExt:0:${#midTestWithExt}-${#midTestExt}-1}"
      runMid "$midTest"
    done
  else # specific tests as specified by user
    runMid "$@"
  fi
  report
}

go "$@"