koa
Version:
631 lines (537 loc) • 12.9 kB
JavaScript
/**
* Module dependencies.
*/
const contentDisposition = require('content-disposition')
const getType = require('cache-content-type')
const onFinish = require('on-finished')
const escape = require('escape-html')
const typeis = require('type-is').is
const statuses = require('statuses')
const destroy = require('destroy')
const assert = require('assert')
const extname = require('path').extname
const vary = require('vary')
const isStream = require('./is-stream.js')
const only = require('./only.js')
const util = require('util')
const encodeUrl = require('encodeurl')
/**
* Prototype.
*/
module.exports = {
/**
* Return the request socket.
*
* @return {Connection}
* @api public
*/
get socket () {
return this.res.socket
},
/**
* Return response header.
*
* @return {Object}
* @api public
*/
get header () {
const { res } = this
return typeof res.getHeaders === 'function'
? res.getHeaders()
: res._headers || {} // Node < 7.7
},
/**
* Return response header, alias as response.header
*
* @return {Object}
* @api public
*/
get headers () {
return this.header
},
/**
* Get response status code.
*
* @return {Number}
* @api public
*/
get status () {
return this.res.statusCode
},
/**
* Set response status code.
*
* @param {Number} code
* @api public
*/
set status (code) {
if (this.headerSent) return
assert(Number.isInteger(code), 'status code must be a number')
assert(code >= 100 && code <= 999, `invalid status code: ${code}`)
this._explicitStatus = true
this.res.statusCode = code
if (this.req.httpVersionMajor < 2) this.res.statusMessage = statuses.message[code]
if (this.body && statuses.empty[code]) this.body = null
},
/**
* Get response status message
*
* @return {String}
* @api public
*/
get message () {
return this.res.statusMessage || statuses.message[this.status]
},
/**
* Set response status message
*
* @param {String} msg
* @api public
*/
set message (msg) {
this.res.statusMessage = msg
},
/**
* Get response body.
*
* @return {Mixed}
* @api public
*/
get body () {
return this._body
},
/**
* Set response body.
*
* @param {String|Buffer|Object|Stream|ReadableStream|Blob|Response} val
* @api public
*/
set body (val) {
const original = this._body
this._body = val
// no content
if (val == null) {
if (!statuses.empty[this.status]) {
if (this.type === 'application/json') {
this._body = 'null'
return
}
this.status = 204
}
if (val === null) this._explicitNullBody = true
this.remove('Content-Type')
this.remove('Content-Length')
this.remove('Transfer-Encoding')
return
}
// set the status
if (!this._explicitStatus) this.status = 200
// set the content-type only if not yet set
const setType = !this.has('Content-Type')
// string
if (typeof val === 'string') {
if (setType) this.type = /^\s*</.test(val) ? 'html' : 'text'
this.length = Buffer.byteLength(val)
return
}
// buffer
if (Buffer.isBuffer(val)) {
if (setType) this.type = 'bin'
this.length = val.length
return
}
// stream
if (isStream(val)) {
onFinish(this.res, destroy.bind(null, val))
if (original !== val) {
val.once('error', err => this.ctx.onerror(err))
// overwriting
if (original != null) this.remove('Content-Length')
}
if (setType) this.type = 'bin'
return
}
// ReadableStream
if (val instanceof ReadableStream) {
if (setType) this.type = 'bin'
return
}
// blob
if (val instanceof Blob) {
if (setType) this.type = 'bin'
this.length = val.size
return
}
// Response
if (val instanceof Response) {
this.status = val.status
if (setType) this.type = 'bin'
const headers = val.headers
for (const key of headers.keys()) {
this.set(key, headers.get(key))
}
return
}
// json
this.remove('Content-Length')
if (!this.type || !/\bjson\b/i.test(this.type)) this.type = 'json'
},
/**
* Set Content-Length field to `n`.
*
* @param {Number} n
* @api public
*/
set length (n) {
if (!this.has('Transfer-Encoding')) {
this.set('Content-Length', n)
}
},
/**
* Return parsed response Content-Length when present.
*
* @return {Number}
* @api public
*/
get length () {
if (this.has('Content-Length')) {
return parseInt(this.get('Content-Length'), 10) || 0
}
const { body } = this
if (!body || isStream(body)) return undefined
if (typeof body === 'string') return Buffer.byteLength(body)
if (Buffer.isBuffer(body)) return body.length
return Buffer.byteLength(JSON.stringify(body))
},
/**
* Check if a header has been written to the socket.
*
* @return {Boolean}
* @api public
*/
get headerSent () {
return this.res.headersSent
},
/**
* Vary on `field`.
*
* @param {String|String[]} field
* @api public
*/
vary (field) {
if (this.headerSent) return
vary(this.res, field)
},
/**
* Perform a 302 redirect to `url`.
*
* Examples:
*
* this.redirect('/login');
* this.redirect('http://google.com');
*
* @param {String} url
* @api public
*/
redirect (url) {
if (/^https?:\/\//i.test(url)) {
// formatting url again avoid security escapes
url = new URL(url).toString()
}
this.set('Location', encodeUrl(url))
// status
if (!statuses.redirect[this.status]) this.status = 302
// html
if (this.ctx.accepts('html')) {
url = escape(url)
this.type = 'text/html; charset=utf-8'
this.body = `Redirecting to ${url}.`
return
}
// text
this.type = 'text/plain; charset=utf-8'
this.body = `Redirecting to ${url}.`
},
/**
* Perform a special-cased "back" to provide Referrer support.
* When Referrer is not present, `alt` or "/" is used.
*
* Examples:
*
* ctx.back()
* ctx.back('/index.html')
*
* @param {String} [alt]
* @api public
*/
back (alt) {
const url = this.ctx.get('Referrer') || alt || '/'
this.redirect(url)
},
/**
* Set Content-Disposition header to "attachment" with optional `filename`.
*
* @param {String} [filename]
* @param {object} [options]
* @param {string} [options.type=attachment]
* @param {string|boolean} [options.fallback=true]
* @api public
*/
attachment (filename, options) {
if (filename) this.type = extname(filename)
this.set('Content-Disposition', contentDisposition(filename, options))
},
/**
* Set Content-Type response header with `type` through `mime.lookup()`
* when it does not contain a charset.
*
* Examples:
*
* this.type = '.html';
* this.type = 'html';
* this.type = 'json';
* this.type = 'application/json';
* this.type = 'png';
*
* @param {String} type
* @api public
*/
set type (type) {
type = getType(type)
if (type) {
this.set('Content-Type', type)
} else {
this.remove('Content-Type')
}
},
/**
* Set the Last-Modified date using a string or a Date.
*
* this.response.lastModified = new Date();
* this.response.lastModified = '2013-09-13';
*
* @param {String|Date} val
* @api public
*/
set lastModified (val) {
if (typeof val === 'string') val = new Date(val)
this.set('Last-Modified', val.toUTCString())
},
/**
* Get the Last-Modified date in Date form, if it exists.
*
* @return {Date}
* @api public
*/
get lastModified () {
const date = this.get('last-modified')
if (date) return new Date(date)
},
/**
* Set the ETag of a response.
* This will normalize the quotes if necessary.
*
* this.response.etag = 'md5hashsum';
* this.response.etag = '"md5hashsum"';
* this.response.etag = 'W/"123456789"';
*
* @param {String} val
* @api public
*/
set etag (val) {
if (!/^(W\/)?"/.test(val)) val = `"${val}"`
this.set('ETag', val)
},
/**
* Get the ETag of a response.
*
* @return {String}
* @api public
*/
get etag () {
return this.get('ETag')
},
/**
* Return the response mime type void of
* parameters such as "charset".
*
* @return {String}
* @api public
*/
get type () {
const type = this.get('Content-Type')
if (!type) return ''
return type.split(';', 1)[0]
},
/**
* Check whether the response is one of the listed types.
* Pretty much the same as `this.request.is()`.
*
* @param {String|String[]} [type]
* @param {String[]} [types]
* @return {String|false}
* @api public
*/
is (type, ...types) {
return typeis(this.type, type, ...types)
},
/**
* Return response header.
*
* Examples:
*
* this.get('Content-Type');
* // => "text/plain"
*
* this.get('content-type');
* // => "text/plain"
*
* @param {String} field
* @return {any}
* @api public
*/
get (field) {
return this.res.getHeader(field)
},
/**
* Returns true if the header identified by name is currently set in the outgoing headers.
* The header name matching is case-insensitive.
*
* Examples:
*
* this.has('Content-Type');
* // => true
*
* this.get('content-type');
* // => true
*
* @param {String} field
* @return {boolean}
* @api public
*/
has (field) {
return typeof this.res.hasHeader === 'function'
? this.res.hasHeader(field)
// Node < 7.7
: field.toLowerCase() in this.headers
},
/**
* Set header `field` to `val` or pass
* an object of header fields.
*
* Examples:
*
* this.set('Foo', ['bar', 'baz']);
* this.set('Accept', 'application/json');
* this.set({ Accept: 'text/plain', 'X-API-Key': 'tobi' });
*
* @param {String|{ [k: string]: any }} field
* @param {any} [val]
* @api public
*/
set (field, val) {
if (this.headerSent || !field) return
if (typeof field === 'string') {
this.res.setHeader(field, val)
} else {
Object.keys(field).forEach(header => this.res.setHeader(header, field[header]))
}
},
/**
* Append additional header `field` with value `val`.
*
* Examples:
*
* ```
* this.append('Link', ['<http://localhost/>', '<http://localhost:3000/>']);
* this.append('Set-Cookie', 'foo=bar; Path=/; HttpOnly');
* this.append('Warning', '199 Miscellaneous warning');
* ```
*
* @param {String} field
* @param {*} val
* @api public
*/
append (field, val) {
const prev = this.get(field)
if (prev) {
val = Array.isArray(prev)
? prev.concat(val)
: [prev].concat(val)
}
return this.set(field, val)
},
/**
* Remove header `field`.
*
* @param {String} field
* @api public
*/
remove (field) {
if (this.headerSent) return
this.res.removeHeader(field)
},
/**
* Checks if the request is writable.
* Tests for the existence of the socket
* as node sometimes does not set it.
*
* @return {Boolean}
* @api private
*/
get writable () {
// can't write any more after response finished
// response.writableEnded is available since Node > 12.9
// https://nodejs.org/api/http.html#http_response_writableended
// response.finished is undocumented feature of previous Node versions
// https://stackoverflow.com/questions/16254385/undocumented-response-finished-in-node-js
if (this.res.writableEnded || this.res.finished) return false
const socket = this.res.socket
// There are already pending outgoing res, but still writable
// https://github.com/nodejs/node/blob/v4.4.7/lib/_http_server.js#L486
if (!socket) return true
return socket.writable
},
/**
* Inspect implementation.
*
* @return {Object}
* @api public
*/
inspect () {
if (!this.res) return
const o = this.toJSON()
o.body = this.body
return o
},
/**
* Return JSON representation.
*
* @return {Object}
* @api public
*/
toJSON () {
return only(this, [
'status',
'message',
'header'
])
},
/**
* Flush any set headers and begin the body
*/
flushHeaders () {
this.res.flushHeaders()
}
}
/**
* Custom inspection implementation for node 6+.
*
* @return {Object}
* @api public
*/
/* istanbul ignore else */
if (util.inspect.custom) {
module.exports[util.inspect.custom] = module.exports.inspect
}