find-my-way
A crazy fast HTTP router, internally uses an highly performant Radix Tree (aka compact Prefix Tree), supports route params, wildcards, and it's framework independent.
If you want to see a benchmark comparison with the most commonly used routers, see here.
Do you need a real-world example that uses this router? Check out Fastify or Restify.
Install
npm i find-my-way --save
Usage
const http = require('http')
const router = require('find-my-way')()
router.on('GET', '/', (req, res, params) => {
res.end('{"message":"hello world"}')
})
const server = http.createServer((req, res) => {
router.lookup(req, res)
})
server.listen(3000, err => {
if (err) throw err
console.log('Server listening on: http://localhost:3000')
})
API
FindMyWay([options])
Instance a new router.
You can pass a default route with the option defaultRoute
.
const router = require('find-my-way')({
defaultRoute: (req, res) => {
res.statusCode = 404
res.end()
}
})
In case of a badly formatted url (eg: /hello/%world
), by default find-my-way
will invoke the defaultRoute
, unless you specify the onBadUrl
option:
const router = require('find-my-way')({
onBadUrl: (path, req, res) => {
res.statusCode = 400
res.end(`Bad path: ${path}`)
}
})
Trailing slashes can be ignored by supplying the ignoreTrailingSlash
option:
const router = require('find-my-way')({
ignoreTrailingSlash: true
})
function handler (req, res, params) {
res.end('foo')
}
router.on('GET', '/foo/', handler)
You can set a custom length for parameters in parametric (standard, regex and multi) routes by using maxParamLength
option, the default value is 100 characters.
If the maximum length limit is reached, the default route will be invoked.
const router = require('find-my-way')({
maxParamLength: 500
})
If you are using a regex based route, find-my-way
will throw an error if detects potentially catastrophic exponential-time regular expressions (internally uses safe-regex2
).
If you want to disable this behavior, pass the option allowUnsafeRegex
.
const router = require('find-my-way')({
allowUnsafeRegex: true
})
According to RFC3986, find-my-way is case sensitive by default.
You can disable this by setting the caseSensitive
option to false
:
in that case, all paths will be matched as lowercase, but the route parameters or wildcards will maintain their original letter casing. You can turn off case sensitivity with:
const router = require('find-my-way')({
caseSensitive: false
})
You can assign a buildPrettyMeta
function to sanitize a route's store
object to use with the prettyPrint
functions. This function should accept a single object and return an object.
const privateKey = new Symbol('private key')
const store = { token: '12345', [privateKey]: 'private value' }
const router = require('find-my-way')({
buildPrettyMeta: route => {
const cleanMeta = Object.assign({}, route.store)
Object.keys(cleanMeta).forEach(k => {
if (typeof k === 'symbol') delete cleanMeta[k]
})
return cleanMeta
}
})
store[privateKey] = 'private value'
router.on('GET', '/hello_world', (req, res) => {}, store)
router.prettyPrint()
Constraints
find-my-way
supports restricting handlers to only match certain requests for the same path. This can be used to support different versions of the same route that conform to a semver based versioning strategy, or restricting some routes to only be available on hosts. find-my-way
has the semver based versioning strategy and a regex based hostname constraint strategy built in.
To constrain a route to only match sometimes, pass constraints
to the route options when registering the route:
findMyWay.on('GET', '/', { constraints: { version: '1.0.2' } }, (req, res) => {
})
findMyWay.on('GET', '/', { constraints: { host: 'example.com' } }, (req, res) => {
})
Constraints can be combined, and route handlers will only match if all of the constraints for the handler match the request. find-my-way
does a boolean AND with each route constraint, not an OR.
find-my-way
will try to match the most constrained handlers first before handler with fewer or no constraints.
Custom Constraint Strategies
Custom constraining strategies can be added and are matched against incoming requests while trying to maintain find-my-way
's high performance. To register a new type of constraint, you must add a new constraint strategy that knows how to match values to handlers, and that knows how to get the constraint value from a request. Register strategies when constructing a router:
const customResponseTypeStrategy = {
name: 'accept',
storage: function () {
let handlers = {}
return {
get: (type) => { return handlers[type] || null },
set: (type, store) => { handlers[type] = store }
}
},
deriveConstraint: (req, ctx) => {
return req.headers['accept']
},
mustMatchWhenDerived: true
}
const router = FindMyWay({ constraints: { accept: customResponseTypeStrategy } });
Once a custom constraint strategy is registered, routes can be added that are constrained using it:
findMyWay.on('GET', '/', { constraints: { accept: 'application/fancy+json' } }, (req, res) => {
})
findMyWay.on('GET', '/', { constraints: { accept: 'application/fancy+xml' } }, (req, res) => {
})
Constraint strategies should be careful to make the deriveConstraint
function performant as it is run for every request matched by the router. See the lib/strategies
directory for examples of the built in constraint strategies.
By default, find-my-way
uses a built in strategies for the version constraint that uses semantic version based matching logic, which is detailed below. It is possible to define an alternative strategy:
const customVersioning = {
name: 'version',
storage: function () {
let versions = {}
return {
get: (version) => { return versions[version] || null },
set: (version, store) => { versions[version] = store }
}
},
deriveConstraint: (req, ctx) => {
return req.headers['accept']
},
mustMatchWhenDerived: true
}
const router = FindMyWay({ constraints: { version: customVersioning } });
The custom strategy object should contain next properties:
storage
- a factory function to store lists of handlers for each possible constraint value. The storage object can use domain-specific storage mechanisms to store handlers in a way that makes sense for the constraint at hand. See lib/strategies
for examples, like the version
constraint strategy that matches using semantic versions, or the host
strategy that allows both exact and regex host constraints.deriveConstraint
- the function to determine the value of this constraint given a request
The signature of the functions and objects must match the one from the example above.
Please, be aware, if you use your own constraining strategy - you use it on your own risk. This can lead both to the performance degradation and bugs which are not related to find-my-way
itself!
on(method, path, [opts], handler, [store])
Register a new route.
router.on('GET', '/example', (req, res, params) => {
})
Last argument, store
is used to pass an object that you can access later inside the handler function. If needed, store
can be updated.
router.on('GET', '/example', (req, res, params, store) => {
assert.equal(store, { message: 'hello world' })
}, { message: 'hello world' })
Versioned routes
If needed, you can provide a version
route constraint, which will allow you to declare multiple versions of the same route that are used selectively when requests ask for different version using the Accept-Version
header. This is useful if you want to support several different behaviours for a given route and different clients select among them.
If you never configure a versioned route, the 'Accept-Version'
header will be ignored. Remember to set a Vary header in your responses with the value you are using for defining the versioning (e.g.: 'Accept-Version'), to prevent cache poisoning attacks. You can also configure this as part your Proxy/CDN.
default
The default versioning strategy follows the semver specification. When using lookup
, find-my-way
will automatically detect the Accept-Version
header and route the request accordingly. Internally find-my-way
uses the semver-store
to get the correct version of the route; advanced ranges and pre-releases currently are not supported.
Be aware that using this feature will cause a degradation of the overall performances of the router.
router.on('GET', '/example', { constraints: { version: '1.2.0' }}, (req, res, params) => {
res.end('Hello from 1.2.0!')
})
router.on('GET', '/example', { constraints: { version: '2.4.0' }}, (req, res, params) => {
res.end('Hello from 2.4.0!')
})
If you declare multiple versions with the same major or minor find-my-way
will always choose the highest compatible with the Accept-Version
header value.
custom
It's also possible to define a custom versioning strategy during the find-my-way
initialization. In this case the logic of matching the request to the specific handler depends on the versioning strategy you use.
on(methods[], path, [opts], handler, [store])
Register a new route for each method specified in the methods
array.
It comes handy when you need to declare multiple routes with the same handler but different methods.
router.on(['GET', 'POST'], '/example', (req, res, params) => {
})
Supported path formats
To register a parametric path, use the colon before the parameter name. For wildcard use the star.
Remember that static routes are always inserted before parametric and wildcard.
router.on('GET', '/example/:userId', (req, res, params) => {}))
router.on('GET', '/example/:userId/:secretToken', (req, res, params) => {}))
router.on('GET', '/example/*', (req, res, params) => {}))
Regular expression routes are supported as well, but pay attention, RegExp are very expensive in term of performance!
If you want to declare a regular expression route, you must put the regular expression inside round parenthesis after the parameter name.
router.on('GET', '/example/:file(^\\d+).png', () => {}))
It's possible to define more than one parameter within the same couple of slash ("/"). Such as:
router.on('GET', '/example/near/:lat-:lng/radius/:r', (req, res, params) => {}))
Remember in this case to use the dash ("-") as parameters separator.
Finally it's possible to have multiple parameters with RegExp.
router.on('GET', '/example/at/:hour(^\\d{2})h:minute(^\\d{2})m', (req, res, params) => {}))
In this case as parameter separator it's possible to use whatever character is not matched by the regular expression.
The last parameter can be made optional if you add a question mark ("?") at the end of the parameters name.
router.on('GET', '/example/posts/:id?', (req, res, params) => {}))
In this case you can request /example/posts
as well as /example/posts/1
. The optional param will be undefined if not specified.
Having a route with multiple parameters may affect negatively the performance, so prefer single parameter approach whenever possible, especially on routes which are on the hot path of your application.
Note that you must encode the parameters containing reserved characters.
If your routes' parameters are not Basic Latin charaters, you may face a performance drop. To avoid it, you can customize the way the parameters are parsed by passing a custom decoding function. Read more about it here.
The parsing function is called when the request URL contains one or more encoded special characters: # $ & + , / : ; = ? @
.
const router = require('find-my-way')({
decodeUriParameters: (stringToDecode) => {
return decodeURIComponent(stringToDecode)
}
})
By default, this module relies on fast-decode-uri-component` to parse the encoded path parameters.
Match order
The routing algorithm matches one chunk at a time (where the chunk is a string between two slashes),
this means that it cannot know if a route is static or dynamic until it finishes to match the URL.
The chunks are matched in the following order:
- static
- parametric
- wildcards
- parametric(regex)
- multi parametric(regex)
So if you declare the following routes
/:userId/foo/bar
/33/:a(^.*$)/:b
and the URL of the incoming request is /33/foo/bar,
the second route will be matched because the first chunk (33) matches the static chunk.
If the URL would have been /32/foo/bar, the first route would have been matched.
Once a url has been matched, find-my-way
will figure out which handler registered for that path matches the request if there are any constraints.
find-my-way
will check the most constrained handlers first, which means the handlers with the most keys in the constraints
object.
If you just want a path containing a colon without declaring a parameter, use a double colon.
For example, /name::customVerb
will be interpreted as /name:customVerb
Supported methods
The router is able to route all HTTP methods defined by http
core module.
off(method, path)
Deregister a route.
router.off('GET', '/example')
off(methods[], path, handler, [store])
Deregister a route for each method specified in the methods
array.
It comes handy when you need to deregister multiple routes with the same path but different methods.
router.off(['GET', 'POST'], '/example')
reset()
Empty router.
router.reset()
Caveats
- It's not possible to register two routes which differs only for their parameters, because internally they would be seen as the same route. In a such case you'll get an early error during the route registration phase. An example is worth thousand words:
const findMyWay = FindMyWay({
defaultRoute: (req, res) => {}
})
findMyWay.on('GET', '/user/:userId(^\\d+)', (req, res, params) => {})
findMyWay.on('GET', '/user/:username(^[a-z]+)', (req, res, params) => {})
Shorthand methods
If you want an even nicer api, you can also use the shorthand methods to declare your routes.
For each HTTP supported method, there's the shorthand method. For example:
router.get(path, handler [, store])
router.delete(path, handler [, store])
router.head(path, handler [, store])
router.patch(path, handler [, store])
router.post(path, handler [, store])
router.put(path, handler [, store])
router.options(path, handler [, store])
If you need a route that supports all methods you can use the all
api.
router.all(path, handler [, store])
lookup(request, response, [context])
Start a new search, request
and response
are the server req/res objects.
If a route is found it will automatically call the handler, otherwise the default route will be called.
The url is sanitized internally, all the parameters and wildcards are decoded automatically.
router.lookup(req, res)
lookup
accepts an optional context which will be the value of this
when executing a handler
router.on('GET', '*', function(req, res) {
res.end(this.greeting);
})
router.lookup(req, res, { greeting: 'Hello, World!' })
find(method, path, [constraints])
Return (if present) the route registered in method:path.
The path must be sanitized, all the parameters and wildcards are decoded automatically.
An object with routing constraints should usually be passed as constraints
, containing keys like the host
for the request, the version
for the route to be matched, or other custom constraint values. If the router is using the default versioning strategy, the version value should be conform to the semver specification. If you want to use the existing constraint strategies to derive the constraint values from an incoming request, use lookup
instead of find
. If no value is passed for constraints
, the router won't match any constrained routes. If using constrained routes, passing undefined
for the constraints leads to undefined behavior and should be avoided.
router.find('GET', '/example', { host: 'fastify.io' })
router.find('GET', '/example', { host: 'fastify.io', version: '1.x' })
prettyPrint([{ commonPrefix: false, includeMeta: true || [] }])
Prints the representation of the internal radix tree, useful for debugging.
findMyWay.on('GET', '/test', () => {})
findMyWay.on('GET', '/test/hello', () => {})
findMyWay.on('GET', '/testing', () => {})
findMyWay.on('GET', '/testing/:param', () => {})
findMyWay.on('PUT', '/update', () => {})
console.log(findMyWay.prettyPrint())
prettyPrint
accepts an optional setting to use the internal routes array
to render the tree.
console.log(findMyWay.prettyPrint({ commonPrefix: false }))
To include a display of the store
data passed to individual routes, the
option includeMeta
may be passed. If set to true
all items will be
displayed, this can also be set to an array specifying which keys (if
present) should be displayed. This information can be further sanitized
by specifying a buildPrettyMeta
function which consumes and returns
an object.
findMyWay.on('GET', '/test', () => {}, { onRequest: () => {}, authIDs => [1,2,3] })
findMyWay.on('GET', '/test/hello', () => {}, { token: 'df123-4567' })
findMyWay.on('GET', '/testing', () => {})
findMyWay.on('GET', '/testing/:param', () => {})
findMyWay.on('PUT', '/update', () => {})
console.log(findMyWay.prettyPrint({ commonPrefix: false, includeMeta: ['onRequest'] }))
console.log(findMyWay.prettyPrint({ commonPrefix: true, includeMeta: true }))
routes
Return the all routes registered at moment, useful for debugging.
const findMyWay = require('find-my-way')()
findMyWay.on('GET', '/test', () => {})
findMyWay.on('GET', '/test/hello', () => {})
console.log(findMyWay.routes)
Acknowledgements
It is inspired by the echo router, some parts have been extracted from trekjs router.
License
find-my-way - MIT
trekjs/router - MIT
Copyright © 2017-2019 Tomas Della Vedova