test_runner.jsonata

(
  $appendPath := function($prefix, $path) {
    $prefix & '/' & $path
  };

  $compare := function($actual, $expected, $path) {(
    $actual_keys := $keys($actual);
    $expected_keys := $keys($expected);

    $appender := function($p){appendPath($path, $p)};
    
    $extra_keys := $filter($actual_keys, function($key) { $not($key in $expected_keys) }) ~> $map($appender);
    $missing_keys := $filter($expected_keys, function($key) { $not($key in $actual_keys) }) ~> $map($appender);

    $diff := $map($actual_keys, function($key) {
       $key in $expected_keys ? findDiff($lookup($actual, $key), $lookup($expected, $key), appendPath($path, $key))
    });
    
    {
       "missing": $missing_keys ~> $append($diff.missing),
       "extra": $extra_keys ~> $append($diff.extra),
       "diff": $diff.diff[]
    }
  )};

  $findDiff := function($actual, $expected, $path) {(
    $actual != $expected ? (
        $type($actual) != $type($expected) ?
            {'diff': {'path': $path, 'diff': 'type', 'expected': $type($expected), 'actual': $type($actual) }} :
            $type($actual) = 'array' ?
            (
                $count($actual) != $count($expected) ?
                    {'diff': {'path': $path, 'diff': 'count', 'expected': $count($expected), 'actual': $count($actual)}}
                    : $map($actual, function($item, $i) {
                        $compare($item, $expected[$i], $path & '[' & $i & ']' )
                    })~>$reduce($append);
            ) :
            $type($actual) = 'object' ? $compare($actual, $expected, $path) :
            {'diff': {'path': $path, 'diff': 'value', 'expected': $expected, 'actual': $actual}}
    )
  )};

  function($name, $expression, $input, $expected) { (
    $assert($expression != null, "Expression must be set");
    $assert($name != null, "Name must be set");
    
    $actual := $eval($expression, $input);
    ($actual != $expected) ? (
      $errors := $compare($actual, $expected);
      $errorReport($errors~>|$|{'test': $name}|);
      {
        'test': $name,
        'result': 'failed',
        'errors': $errors
      }
    )
    : {
        'test': $name,
        'result': 'passed'
      }
  )}
)