test

type-is/index.js

@@ -0,0 +1,266 @@
+/*!
+ * type-is
+ * Copyright(c) 2014 Jonathan Ong
+ * Copyright(c) 2014-2015 Douglas Christopher Wilson
+ * MIT Licensed
+ */
+
+'use strict'
+
+/**
+ * Module dependencies.
+ * @private
+ */
+
+var typer = require('media-typer')
+var mime = require('mime-types')
+
+/**
+ * Module exports.
+ * @public
+ */
+
+module.exports = typeofrequest
+module.exports.is = typeis
+module.exports.hasBody = hasbody
+module.exports.normalize = normalize
+module.exports.match = mimeMatch
+
+/**
+ * Compare a `value` content-type with `types`.
+ * Each `type` can be an extension like `html`,
+ * a special shortcut like `multipart` or `urlencoded`,
+ * or a mime type.
+ *
+ * If no types match, `false` is returned.
+ * Otherwise, the first `type` that matches is returned.
+ *
+ * @param {String} value
+ * @param {Array} types
+ * @public
+ */
+
+function typeis (value, types_) {
+  var i
+  var types = types_
+
+  // remove parameters and normalize
+  var val = tryNormalizeType(value)
+
+  // no type or invalid
+  if (!val) {
+    return false
+  }
+
+  // support flattened arguments
+  if (types && !Array.isArray(types)) {
+    types = new Array(arguments.length - 1)
+    for (i = 0; i < types.length; i++) {
+      types[i] = arguments[i + 1]
+    }
+  }
+
+  // no types, return the content type
+  if (!types || !types.length) {
+    return val
+  }
+
+  var type
+  for (i = 0; i < types.length; i++) {
+    if (mimeMatch(normalize(type = types[i]), val)) {
+      return type[0] === '+' || type.indexOf('*') !== -1
+        ? val
+        : type
+    }
+  }
+
+  // no matches
+  return false
+}
+
+/**
+ * Check if a request has a request body.
+ * A request with a body __must__ either have `transfer-encoding`
+ * or `content-length` headers set.
+ * http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.3
+ *
+ * @param {Object} request
+ * @return {Boolean}
+ * @public
+ */
+
+function hasbody (req) {
+  return req.headers['transfer-encoding'] !== undefined ||
+    !isNaN(req.headers['content-length'])
+}
+
+/**
+ * Check if the incoming request contains the "Content-Type"
+ * header field, and it contains any of the give mime `type`s.
+ * If there is no request body, `null` is returned.
+ * If there is no content type, `false` is returned.
+ * Otherwise, it returns the first `type` that matches.
+ *
+ * Examples:
+ *
+ *     // With Content-Type: text/html; charset=utf-8
+ *     this.is('html'); // => 'html'
+ *     this.is('text/html'); // => 'text/html'
+ *     this.is('text/*', 'application/json'); // => 'text/html'
+ *
+ *     // When Content-Type is application/json
+ *     this.is('json', 'urlencoded'); // => 'json'
+ *     this.is('application/json'); // => 'application/json'
+ *     this.is('html', 'application/*'); // => 'application/json'
+ *
+ *     this.is('html'); // => false
+ *
+ * @param {String|Array} types...
+ * @return {String|false|null}
+ * @public
+ */
+
+function typeofrequest (req, types_) {
+  var types = types_
+
+  // no body
+  if (!hasbody(req)) {
+    return null
+  }
+
+  // support flattened arguments
+  if (arguments.length > 2) {
+    types = new Array(arguments.length - 1)
+    for (var i = 0; i < types.length; i++) {
+      types[i] = arguments[i + 1]
+    }
+  }
+
+  // request content type
+  var value = req.headers['content-type']
+
+  return typeis(value, types)
+}
+
+/**
+ * Normalize a mime type.
+ * If it's a shorthand, expand it to a valid mime type.
+ *
+ * In general, you probably want:
+ *
+ *   var type = is(req, ['urlencoded', 'json', 'multipart']);
+ *
+ * Then use the appropriate body parsers.
+ * These three are the most common request body types
+ * and are thus ensured to work.
+ *
+ * @param {String} type
+ * @private
+ */
+
+function normalize (type) {
+  if (typeof type !== 'string') {
+    // invalid type
+    return false
+  }
+
+  switch (type) {
+    case 'urlencoded':
+      return 'application/x-www-form-urlencoded'
+    case 'multipart':
+      return 'multipart/*'
+  }
+
+  if (type[0] === '+') {
+    // "+json" -> "*/*+json" expando
+    return '*/*' + type
+  }
+
+  return type.indexOf('/') === -1
+    ? mime.lookup(type)
+    : type
+}
+
+/**
+ * Check if `expected` mime type
+ * matches `actual` mime type with
+ * wildcard and +suffix support.
+ *
+ * @param {String} expected
+ * @param {String} actual
+ * @return {Boolean}
+ * @private
+ */
+
+function mimeMatch (expected, actual) {
+  // invalid type
+  if (expected === false) {
+    return false
+  }
+
+  // split types
+  var actualParts = actual.split('/')
+  var expectedParts = expected.split('/')
+
+  // invalid format
+  if (actualParts.length !== 2 || expectedParts.length !== 2) {
+    return false
+  }
+
+  // validate type
+  if (expectedParts[0] !== '*' && expectedParts[0] !== actualParts[0]) {
+    return false
+  }
+
+  // validate suffix wildcard
+  if (expectedParts[1].substr(0, 2) === '*+') {
+    return expectedParts[1].length <= actualParts[1].length + 1 &&
+      expectedParts[1].substr(1) === actualParts[1].substr(1 - expectedParts[1].length)
+  }
+
+  // validate subtype
+  if (expectedParts[1] !== '*' && expectedParts[1] !== actualParts[1]) {
+    return false
+  }
+
+  return true
+}
+
+/**
+ * Normalize a type and remove parameters.
+ *
+ * @param {string} value
+ * @return {string}
+ * @private
+ */
+
+function normalizeType (value) {
+  // parse the type
+  var type = typer.parse(value)
+
+  // remove the parameters
+  type.parameters = undefined
+
+  // reformat it
+  return typer.format(type)
+}
+
+/**
+ * Try to normalize a type and remove parameters.
+ *
+ * @param {string} value
+ * @return {string}
+ * @private
+ */
+
+function tryNormalizeType (value) {
+  if (!value) {
+    return null
+  }
+
+  try {
+    return normalizeType(value)
+  } catch (err) {
+    return null
+  }
+}