fuse-box/modules/path/index.js

Fuse-Box a bundler that does it right

function normalizeArray(parts, allowAboveRoot) {
  // if the path tries to go above the root, `up` ends up > 0
  var up = 0;
  for (var i = parts.length - 1; i >= 0; i--) {
    var last = parts[i];
    if (last === '.') {
      parts.splice(i, 1);
    } else if (last === '..') {
      parts.splice(i, 1);
      up++;
    } else if (up) {
      parts.splice(i, 1);
      up--;
    }
  }

  // if the path is allowed to go above the root, restore leading ..s
  if (allowAboveRoot) {
    for (; up--; up) {
      parts.unshift('..');
    }
  }

  return parts;
}

// Split a filename into [root, dir, basename, ext], unix version
// 'root' is just a slash, or nothing.
var splitPathRe = /^(\/?|)([\s\S]*?)((?:\.{1,2}|[^\/]+?|)(\.[^.\/]*|))(?:[\/]*)$/;
var splitPath = function(filename) {
  return splitPathRe.exec(filename).slice(1);
};

// path.resolve([from ...], to)
// posix version
exports.resolve = function() {
  var resolvedPath = '',
    resolvedAbsolute = false;

  for (var i = arguments.length - 1; i >= -1 && !resolvedAbsolute; i--) {
    var path = i >= 0 ? arguments[i] : '/';

    // Skip empty and invalid entries
    if (typeof path !== 'string') {
      throw new TypeError('Arguments to path.resolve must be strings');
    } else if (!path) {
      continue;
    }

    resolvedPath = path + '/' + resolvedPath;
    resolvedAbsolute = path.charAt(0) === '/';
  }

  // At this point the path should be resolved to a full absolute path, but
  // handle relative paths to be safe (might happen when process.cwd() fails)

  // Normalize the path
  resolvedPath = normalizeArray(
    filter(resolvedPath.split('/'), function(p) {
      return !!p;
    }),
    !resolvedAbsolute,
  ).join('/');

  return (resolvedAbsolute ? '/' : '') + resolvedPath || '.';
};

// path.normalize(path)
// posix version
exports.normalize = function(path) {
  var isAbsolute = exports.isAbsolute(path),
    trailingSlash = substr(path, -1) === '/';

  // Normalize the path
  path = normalizeArray(
    filter(path.split('/'), function(p) {
      return !!p;
    }),
    !isAbsolute,
  ).join('/');

  if (!path && !isAbsolute) {
    path = '.';
  }
  if (path && trailingSlash) {
    path += '/';
  }

  return (isAbsolute ? '/' : '') + path;
};

// posix version
exports.isAbsolute = function(path) {
  return path.charAt(0) === '/';
};

// posix version
exports.join = function() {
  var paths = Array.prototype.slice.call(arguments, 0);
  return exports.normalize(
    filter(paths, function(p, index) {
      if (typeof p !== 'string') {
        throw new TypeError('Arguments to path.join must be strings');
      }
      return p;
    }).join('/'),
  );
};

// path.relative(from, to)
// posix version
exports.relative = function(from, to) {
  from = exports.resolve(from).substr(1);
  to = exports.resolve(to).substr(1);

  function trim(arr) {
    var start = 0;
    for (; start < arr.length; start++) {
      if (arr[start] !== '') break;
    }

    var end = arr.length - 1;
    for (; end >= 0; end--) {
      if (arr[end] !== '') break;
    }

    if (start > end) return [];
    return arr.slice(start, end - start + 1);
  }

  var fromParts = trim(from.split('/'));
  var toParts = trim(to.split('/'));

  var length = Math.min(fromParts.length, toParts.length);
  var samePartsLength = length;
  for (var i = 0; i < length; i++) {
    if (fromParts[i] !== toParts[i]) {
      samePartsLength = i;
      break;
    }
  }

  var outputParts = [];
  for (var i = samePartsLength; i < fromParts.length; i++) {
    outputParts.push('..');
  }

  outputParts = outputParts.concat(toParts.slice(samePartsLength));

  return outputParts.join('/');
};

exports.sep = '/';
exports.delimiter = ':';

exports.dirname = function(path) {
  var result = splitPath(path),
    root = result[0],
    dir = result[1];

  if (!root && !dir) {
    // No dirname whatsoever
    return '.';
  }

  if (dir) {
    // It has a dirname, strip trailing slash
    dir = dir.substr(0, dir.length - 1);
  }

  return root + dir;
};

exports.basename = function(path, ext) {
  var f = splitPath(path)[2];
  // TODO: make this comparison case-insensitive on windows?
  if (ext && f.substr(-1 * ext.length) === ext) {
    f = f.substr(0, f.length - ext.length);
  }
  return f;
};

exports.extname = function(path) {
  return splitPath(path)[3];
};

function filter(xs, f) {
  if (xs.filter) return xs.filter(f);
  var res = [];
  for (var i = 0; i < xs.length; i++) {
    if (f(xs[i], i, xs)) res.push(xs[i]);
  }
  return res;
}

// String.prototype.substr - negative index don't work in IE8
var substr =
  'ab'.substr(-1) === 'b'
    ? function(str, start, len) {
        return str.substr(start, len);
      }
    : function(str, start, len) {
        if (start < 0) start = str.length + start;
        return str.substr(start, len);
      };