elxr/cliargs.js

// -------------------------------
// Command line option parsing
// -------------------------------
function cliargs(args, opts) {
  if (!opts) opts = {};
  
  var flags = { bools : {}, strings : {}, unknownFn: null };

  if (typeof opts['unknown'] === 'function') {
      flags.unknownFn = opts['unknown'];
  }

  if (typeof opts['boolean'] === 'boolean' && opts['boolean']) {
    flags.allBools = true;
  } else {
    [].concat(opts['boolean']).filter(Boolean).forEach(function (key) {
        flags.bools[key] = true;
    });
  }
  
  var aliases = {};
  Object.keys(opts.alias || {}).forEach(function (key) {
      aliases[key] = [].concat(opts.alias[key]);
      aliases[key].forEach(function (x) {
          aliases[x] = [key].concat(aliases[key].filter(function (y) {
              return x !== y;
          }));
      });
  });

  [].concat(opts.string).filter(Boolean).forEach(function (key) {
      flags.strings[key] = true;
      if (aliases[key]) {
          flags.strings[aliases[key]] = true;
      }
   });

  var defaults = opts['default'] || {};
  
  var argv = { _ : [] };
  Object.keys(flags.bools).forEach(function (key) {
      setArg(key, defaults[key] === undefined ? false : defaults[key]);
  });
  
  var notFlags = [];

  if (args.indexOf('--') !== -1) {
      notFlags = args.slice(args.indexOf('--')+1);
      args = args.slice(0, args.indexOf('--'));
  }

  function argDefined(key, arg) {
      return (flags.allBools && /^--[^=]+$/.test(arg)) ||
          flags.strings[key] || flags.bools[key] || aliases[key];
  }

  function setArg (key, val, arg) {
      if (arg && flags.unknownFn && !argDefined(key, arg)) {
          if (flags.unknownFn(arg) === false) return;
      }

      var value = !flags.strings[key] && isNumber(val)
          ? Number(val) : val
      ;
      setKey(argv, key.split('.'), value);
      
      (aliases[key] || []).forEach(function (x) {
          setKey(argv, x.split('.'), value);
      });
  }

  function setKey (obj, keys, value) {
      var o = obj;
      keys.slice(0,-1).forEach(function (key) {
          if (o[key] === undefined) o[key] = {};
          o = o[key];
      });

      var key = keys[keys.length - 1];
      if (o[key] === undefined || flags.bools[key] || typeof o[key] === 'boolean') {
          o[key] = value;
      }
      else if (Array.isArray(o[key])) {
          o[key].push(value);
      }
      else {
          o[key] = [ o[key], value ];
      }
  }
  
  function aliasIsBoolean(key) {
    return aliases[key].some(function (x) {
        return flags.bools[x];
    });
  }

  for (var i = 0; i < args.length; i++) {
      var arg = args[i];
      
      if (/^--.+=/.test(arg)) {
          // Using [\s\S] instead of . because js doesn't support the
          // 'dotall' regex modifier. See:
          // http://stackoverflow.com/a/1068308/13216
          var m = arg.match(/^--([^=]+)=([\s\S]*)$/);
          var key = m[1];
          var value = m[2];
          if (flags.bools[key]) {
              value = value !== 'false';
          }
          setArg(key, value, arg);
      }
      else if (/^--no-.+/.test(arg)) {
          var key = arg.match(/^--no-(.+)/)[1];
          setArg(key, false, arg);
      }
      else if (/^--.+/.test(arg)) {
          var key = arg.match(/^--(.+)/)[1];
          var next = args[i + 1];
          if (next !== undefined && !/^-/.test(next)
          && !flags.bools[key]
          && !flags.allBools
          && (aliases[key] ? !aliasIsBoolean(key) : true)) {
              setArg(key, next, arg);
              i++;
          }
          else if (/^(true|false)$/.test(next)) {
              setArg(key, next === 'true', arg);
              i++;
          }
          else {
              setArg(key, flags.strings[key] ? '' : true, arg);
          }
      }
      else if (/^-[^-]+/.test(arg)) {
          var letters = arg.slice(1,-1).split('');
          
          var broken = false;
          for (var j = 0; j < letters.length; j++) {
              var next = arg.slice(j+2);
              
              if (next === '-') {
                  setArg(letters[j], next, arg)
                  continue;
              }
              
              if (/[A-Za-z]/.test(letters[j]) && /=/.test(next)) {
                  setArg(letters[j], next.split('=')[1], arg);
                  broken = true;
                  break;
              }
              
              if (/[A-Za-z]/.test(letters[j])
              && /-?\d+(\.\d*)?(e-?\d+)?$/.test(next)) {
                  setArg(letters[j], next, arg);
                  broken = true;
                  break;
              }
              
              if (letters[j+1] && letters[j+1].match(/\W/)) {
                  setArg(letters[j], arg.slice(j+2), arg);
                  broken = true;
                  break;
              }
              else {
                  setArg(letters[j], flags.strings[letters[j]] ? '' : true, arg);
              }
          }
          
          var key = arg.slice(-1)[0];
          if (!broken && key !== '-') {
              if (args[i+1] && !/^(-|--)[^-]/.test(args[i+1])
              && !flags.bools[key]
              && (aliases[key] ? !aliasIsBoolean(key) : true)) {
                  setArg(key, args[i+1], arg);
                  i++;
              }
              else if (args[i+1] && /true|false/.test(args[i+1])) {
                  setArg(key, args[i+1] === 'true', arg);
                  i++;
              }
              else {
                  setArg(key, flags.strings[key] ? '' : true, arg);
              }
          }
      }
      else {
          if (!flags.unknownFn || flags.unknownFn(arg) !== false) {
              argv._.push(
                  flags.strings['_'] || !isNumber(arg) ? arg : Number(arg)
              );
          }
          if (opts.stopEarly) {
              argv._.push.apply(argv._, args.slice(i + 1));
              break;
          }
      }
  }
  
  Object.keys(defaults).forEach(function (key) {
      if (!hasKey(argv, key.split('.'))) {
          setKey(argv, key.split('.'), defaults[key]);
          
          (aliases[key] || []).forEach(function (x) {
              setKey(argv, x.split('.'), defaults[key]);
          });
      }
  });
  
  if (opts['--']) {
      argv['--'] = new Array();
      notFlags.forEach(function(key) {
          argv['--'].push(key);
      });
  }
  else {
      notFlags.forEach(function(key) {
          argv._.push(key);
      });
  }

  return argv;
};

function hasKey (obj, keys) {
  var o = obj;
  keys.slice(0,-1).forEach(function (key) {
      o = (o[key] || {});
  });

  var key = keys[keys.length - 1];
  return key in o;
}

function isNumber (x) {
  if (typeof x === 'number') return true;
  if (/^0x[0-9a-f]+$/i.test(x)) return true;
  return /^[-+]?(?:\d+(?:\.\d*)?|\.\d+)(e[-+]?\d+)?$/.test(x);
}

module.exports = cliargs;