FM / vary

/opt/canhelp/node_modules/vary

Name	Size	Mode	Actions
HISTORY.md	792	0644	edit dl rm
index.js	2930	0644	edit dl rm
LICENSE	1094	0644	edit dl rm
package.json	1215	0644	edit dl rm
README.md	2716	0644	edit dl rm

Edit: /opt/canhelp/node_modules/vary/index.js (2930B)

/*!
 * vary
 * Copyright(c) 2014-2017 Douglas Christopher Wilson
 * MIT Licensed
 */

'use strict'

/**
 * Module exports.
 */

module.exports = vary
module.exports.append = append

/**
 * RegExp to match field-name in RFC 7230 sec 3.2
 *
 * field-name    = token
 * token         = 1*tchar
 * tchar         = "!" / "#" / "$" / "%" / "&" / "'" / "*"
 *               / "+" / "-" / "." / "^" / "_" / "`" / "|" / "~"
 *               / DIGIT / ALPHA
 *               ; any VCHAR, except delimiters
 */

var FIELD_NAME_REGEXP = /^[!#$%&'*+\-.^_`|~0-9A-Za-z]+$/

/**
 * Append a field to a vary header.
 *
 * @param {String} header
 * @param {String|Array} field
 * @return {String}
 * @public
 */

function append (header, field) {
  if (typeof header !== 'string') {
    throw new TypeError('header argument is required')
  }

if (!field) {
    throw new TypeError('field argument is required')
  }

// get fields array
  var fields = !Array.isArray(field)
    ? parse(String(field))
    : field

// assert on invalid field names
  for (var j = 0; j < fields.length; j++) {
    if (!FIELD_NAME_REGEXP.test(fields[j])) {
      throw new TypeError('field argument contains an invalid header name')
    }
  }

// existing, unspecified vary
  if (header === '*') {
    return header
  }

// enumerate current values
  var val = header
  var vals = parse(header.toLowerCase())

// unspecified vary
  if (fields.indexOf('*') !== -1 || vals.indexOf('*') !== -1) {
    return '*'
  }

for (var i = 0; i < fields.length; i++) {
    var fld = fields[i].toLowerCase()

// append value (case-preserving)
    if (vals.indexOf(fld) === -1) {
      vals.push(fld)
      val = val
        ? val + ', ' + fields[i]
        : fields[i]
    }
  }

return val
}

/**
 * Parse a vary header into an array.
 *
 * @param {String} header
 * @return {Array}
 * @private
 */

function parse (header) {
  var end = 0
  var list = []
  var start = 0

// gather tokens
  for (var i = 0, len = header.length; i < len; i++) {
    switch (header.charCodeAt(i)) {
      case 0x20: /*   */
        if (start === end) {
          start = end = i + 1
        }
        break
      case 0x2c: /* , */
        list.push(header.substring(start, end))
        start = end = i + 1
        break
      default:
        end = i + 1
        break
    }
  }

// final token
  list.push(header.substring(start, end))

return list
}

/**
 * Mark that a request is varied on a header field.
 *
 * @param {Object} res
 * @param {String|Array} field
 * @public
 */

function vary (res, field) {
  if (!res || !res.getHeader || !res.setHeader) {
    // quack quack
    throw new TypeError('res argument is required')
  }

// get existing header
  var val = res.getHeader('Vary') || ''
  var header = Array.isArray(val)
    ? val.join(', ')
    : String(val)

// set new header
  if ((val = append(header, field))) {
    res.setHeader('Vary', val)
  }
}

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