fastify@fastify/send
Send is a library for streaming files from the file system as an HTTP response supporting partial responses (Ranges), conditional-GET negotiation (If-Match, If-Unmodified-Since, If-None-Match, If-Modified-Since), high test coverage, and granular events which may be leveraged to take appropriate actions in your application or framework.
Installation
This is a Node.js module available through the
npm registry. Installation is done using the
npm install command:
$ npm install @fastify/send
TypeScript
@types/mime@3 must be used if wanting to use TypeScript;
@types/mime@4 removed the mime types.
$ npm install -D @types/mime@3
API
const send = require('@fastify/send')
send(req, path, [options])
Provide statusCode, headers, and stream for the given path to send to a
res. The req is the Node.js HTTP request and the pathis a urlencoded path
to send (urlencoded, not the actual file-system path).
Options
acceptRanges
Enable or disable accepting ranged requests, defaults to true.
Disabling this will not send Accept-Ranges and ignore the contents
of the Range request header.
cacheControl
Enable or disable setting Cache-Control response header, defaults to
true. Disabling this will ignore the immutable and maxAge options.
contentType
By default, this library uses the mime module to set the Content-Type
of the response based on the file extension of the requested file.
To disable this functionality, set contentType to false.
The Content-Type header will need to be set manually if disabled.
dotfiles
Set how "dotfiles" are treated when encountered. A dotfile is a file
or directory that begins with a dot ("."). Note this check is done on
the path itself without checking if the path exists on the
disk. If root is specified, only the dotfiles above the root are
checked (i.e. the root itself can be within a dotfile when set
to "deny").
'allow'No special treatment for dotfiles.'deny'Send a 403 for any request for a dotfile.'ignore'Pretend like the dotfile does not exist and 404.
The default value is similar to 'ignore', with the exception that
this default will not ignore the files within a directory that begins
with a dot, for backward-compatibility.
end
Byte offset at which the stream ends, defaults to the length of the file
minus 1. The end is inclusive in the stream, meaning end: 3 will include
the 4th byte in the stream.
etag
Enable or disable etag generation, defaults to true.
extensions
If a given file doesn't exist, try appending one of the given extensions,
in the given order. By default, this is disabled (set to false). An
example value that will serve extension-less HTML files: ['html', 'htm'].
This is skipped if the requested file already has an extension.
immutable
Enable or disable the immutable directive in the Cache-Control response
header, defaults to false. If set to true, the maxAge option should
also be specified to enable caching. The immutable directive will prevent
supported clients from making conditional requests during the life of the
maxAge option to check if the file has changed.
index
By default send supports "index.html" files, to disable this
set false or to supply a new index pass a string or an array
in preferred order.
lastModified
Enable or disable Last-Modified header, defaults to true. Uses the file
system's last modified value.
maxAge
Provide a max-age in milliseconds for HTTP caching, defaults to 0. This can also be a string accepted by the ms module.
maxContentRangeChunkSize
Specify the maximum response content size, defaults to the entire file size.
This will be used when acceptRanges is true.
root
Serve files relative to path.
start
Byte offset at which the stream starts, defaults to 0. The start is inclusive,
meaning start: 2 will include the 3rd byte in the stream.
highWaterMark
When provided, this option sets the maximum number of bytes that the internal buffer will hold before pausing reads from the underlying resource. If you omit this option (or pass undefined), Node.js falls back to its built-in default for readable binary streams.
.mime
The mime export is the global instance of the
mime npm module.
This is used to configure the MIME types that are associated with file extensions as well as other options for how to resolve the MIME type of a file (like the default type to use for an unknown file extension).
Caching
It does not perform internal caching, you should use a reverse proxy cache such as Varnish for this, or those fancy things called CDNs. If your application is small enough that it would benefit from single-node memory caching, it's small enough that it does not need caching at all ;).
Debugging
To enable debug() instrumentation output export NODE_DEBUG:
$ NODE_DEBUG=send node app
Running tests
$ npm install
$ npm test
Examples
Serve a specific file
This simple example will send a specific file to all requests.
const http = require('node:http')
const send = require('send')
const server = http.createServer(async function onRequest (req, res) {
const { statusCode, headers, stream } = await send(req, '/path/to/index.html')
res.writeHead(statusCode, headers)
stream.pipe(res)
})
server.listen(3000)
Serve all files from a directory
This simple example will just serve up all the files in a
given directory as the top-level. For example, a request
GET /foo.txt will send back /www/public/foo.txt.
const http = require('node:http')
const parseUrl = require('parseurl')
const send = require('@fastify/send')
const server = http.createServer(async function onRequest (req, res) {
const { statusCode, headers, stream } = await send(req, parseUrl(req).pathname, { root: '/www/public' })
res.writeHead(statusCode, headers)
stream.pipe(res)
})
server.listen(3000)
Custom file types
const http = require('node:http')
const parseUrl = require('parseurl')
const send = require('@fastify/send')
// Default unknown types to text/plain
send.mime.default_type = 'text/plain'
// Add a custom type
send.mime.define({
'application/x-my-type': ['x-mt', 'x-mtt']
})
const server = http.createServer(function onRequest (req, res) {
const { statusCode, headers, stream } = await send(req, parseUrl(req).pathname, { root: '/www/public' })
res.writeHead(statusCode, headers)
stream.pipe(res)
})
server.listen(3000)
Custom directory index view
This is an example of serving up a structure of directories with a custom function to render a listing of a directory.
const http = require('node:http')
const fs = require('node:fs')
const parseUrl = require('parseurl')
const send = require('@fastify/send')
// Transfer arbitrary files from within /www/example.com/public/*
// with a custom handler for directory listing
const server = http.createServer(async function onRequest (req, res) {
const { statusCode, headers, stream, type, metadata } = await send(req, parseUrl(req).pathname, { index: false, root: '/www/public' })
if(type === 'directory') {
// get directory list
const list = await readdir(metadata.path)
// render an index for the directory
res.writeHead(200, { 'Content-Type': 'text/plain; charset=utf-8' })
res.end(list.join('\n') + '\n')
} else {
res.writeHead(statusCode, headers)
stream.pipe(res)
}
})
server.listen(3000)
Serving from a root directory with custom error-handling
const http = require('node:http')
const parseUrl = require('parseurl')
const send = require('@fastify/send')
const server = http.createServer(async function onRequest (req, res) {
// transfer arbitrary files from within
// /www/example.com/public/*
const { statusCode, headers, stream, type, metadata } = await send(req, parseUrl(req).pathname, { root: '/www/public' })
switch (type) {
case 'directory': {
// your custom directory handling logic:
res.writeHead(301, {
'Location': metadata.requestPath + '/'
})
res.end('Redirecting to ' + metadata.requestPath + '/')
break
}
case 'error': {
// your custom error-handling logic:
res.writeHead(metadata.error.status ?? 500, {})
res.end(metadata.error.message)
break
}
default: {
// your custom headers
// serve all files for download
res.setHeader('Content-Disposition', 'attachment')
res.writeHead(statusCode, headers)
stream.pipe(res)
}
}
})
server.listen(3000)
License
Licensed under MIT.