Repository: delvedor/find-my-way (js)

Issue:
Decoding URL Components
There is how decoding URL components is working right now. If URL contains "%" symbol - URL will be decoded by standard js decodeURI function and if URL contains one of this symbols "# $ & + , / : ; = ? @", URL params will be parsed from the original (non-decoded) url and will be decoded either by fastDecode or customDecode function. There is a problem here. If one part of a URL has one of this symbols "# $ & + , / : ; = ? @", all url params will be parsed by fastDecode function and not parsed with decodeURI function. 

```js
test('Decode url components', t => {
  t.plan(3)

  const findMyWay = FindMyWay()

  findMyWay.on('GET', '/:param1/:param2', () => {})

  t.same(findMyWay.find('GET', '/foo%23bar/foo%23bar').params, { param1: 'foo#bar', param2: 'foo#bar' })
  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/%F0%9F%8D%8C').params, { param1: '🍌', param2: '🍌' })
  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/foo%23bar'), null) // shouldn't be true
  // t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/foo%23bar'), { param1: '🍌', param2: 'foo#bar' }) // should be true
})
```

Pull request description:
Fix parameters decoding
Fix #234 and a bunch of optimization to make it work as fast as possible. 

Patch:
diff --git a/index.js b/index.js
index 910c451..d78eb59 100644
--- a/index.js
+++ b/index.js
@@ -32,7 +32,7 @@ const deepEqual = require('fast-deep-equal')
 const { flattenNode, compressFlattenedNode, prettyPrintFlattenedNode, prettyPrintRoutesArray } = require('./lib/pretty-print')
 const { StaticNode, NODE_TYPES } = require('./custom_node')
 const Constrainer = require('./lib/constrainer')
-const sanitizeUrl = require('./lib/url-sanitizer')
+const { safeDecodeURI, safeDecodeURIComponent } = require('./lib/url-sanitizer')
 
 const httpMethods = http.METHODS
 const FULL_PATH_REGEXP = /^https?:\/\/.*?\//
@@ -85,6 +85,7 @@ function Router (opts) {
   this.routes = []
   this.trees = {}
 
+  this.decodeURIComponent = opts.decodeUriParameters || safeDecodeURIComponent
   this.constrainer = new Constrainer(opts.constraints)
 }
 
@@ -167,6 +168,12 @@ Router.prototype._on = function _on (method, path, opts, handler, store) {
       continue
     }
 
+    if (path.charCodeAt(i) === 37) {
+      // We need to encode % char to prevent double decoding
+      path = path.slice(0, i + 1) + '25' + path.slice(i + 1)
+      continue
+    }
+
     const isParametricNode = path.charCodeAt(i) === 58
     const isWildcardNode = path.charCodeAt(i) === 42
 
@@ -329,10 +336,8 @@ Router.prototype.find = function find (method, path, derivedConstraints) {
     path = path.replace(FULL_PATH_REGEXP, '/')
   }
 
-  let sanitizedUrl
   try {
-    sanitizedUrl = sanitizeUrl(path, this.decodeUriParameters)
-    path = sanitizedUrl.path
+    path = safeDecodeURI(path)
   } catch (error) {
     return this._onBadUrl(path)
   }
@@ -341,6 +346,8 @@ Router.prototype.find = function find (method, path, derivedConstraints) {
     path = trimLastSlash(path)
   }
 
+  const originPath = path
+
   if (this.caseSensitive === false) {
     path = path.toLowerCase()
   }
@@ -429,49 +436,55 @@ Router.prototype.find = function find (method, path, derivedConstraints) {
     }
 
     if (currentNode.kind === NODE_TYPES.WILDCARD) {
-      const decoded = sanitizedUrl.sliceParameter(pathIndex)
-      if (decoded === null) {
-        return this._onBadUrl(path.slice(pathIndex))
+      let param = originPath.slice(pathIndex)
+
+      const firstPercentIndex = param.indexOf('%')
+      if (firstPercentIndex !== -1) {
+        param = this.decodeURIComponent(param, firstPercentIndex)
       }
 
-      if (decoded.length > maxParamLength) {
+      if (param.length > maxParamLength) {
         return null
       }
 
-      params.push(decoded)
+      params.push(param)
       pathIndex = pathLen
       continue
     }
 
     if (currentNode.kind === NODE_TYPES.PARAMETRIC) {
       let paramEndIndex = pathIndex
+      let firstPercentIndex = -1
       for (; paramEndIndex < pathLen; paramEndIndex++) {
-        if (path.charCodeAt(paramEndIndex) === 47) {
+        const charCode = path.charCodeAt(paramEndIndex)
+        if (charCode === 47) {
           break
+        } else if (firstPercentIndex === -1 && charCode === 37) {
+          firstPercentIndex = paramEndIndex - pathIndex
         }
       }
 
-      const decoded = sanitizedUrl.sliceParameter(pathIndex, paramEndIndex)
-      if (decoded === null) {
-        return this._onBadUrl(path.slice(pathIndex, paramEndIndex))
+      let param = originPath.slice(pathIndex, paramEndIndex)
+      if (firstPercentIndex !== -1) {
+        param = this.decodeURIComponent(param, firstPercentIndex)
       }
 
       if (currentNode.isRegex) {
-        const matchedParameters = currentNode.regex.exec(decoded)
+        const matchedParameters = currentNode.regex.exec(param)
         if (matchedParameters === null) continue
 
         for (let i = 1; i < matchedParameters.length; i++) {
-          const param = matchedParameters[i]
-          if (param.length > maxParamLength) {
+          const matchedParam = matchedParameters[i]
+          if (matchedParam.length > maxParamLength) {
             return null
           }
-          params.push(param)
+          params.push(matchedParam)
         }
       } else {
-        if (decoded.length > maxParamLength) {
+        if (param.length > maxParamLength) {
           return null
         }
-        params.push(decoded)
+        params.push(param)
       }
 
       pathIndex = paramEndIndex
diff --git a/lib/url-sanitizer.js b/lib/url-sanitizer.js
index a0ef94c..368ba72 100644
--- a/lib/url-sanitizer.js
+++ b/lib/url-sanitizer.js
@@ -1,83 +1,87 @@
 'use strict'
 
-const fastDecode = require('fast-decode-uri-component')
-
 // It must spot all the chars where decodeURIComponent(x) !== decodeURI(x)
 // The chars are: # $ & + , / : ; = ? @
-const uriComponentsCharMap = new Array(53).fill(0x00)
-uriComponentsCharMap[50] = new Array(103).fill(0x00)
-uriComponentsCharMap[50][51] = true // # '%23'
-uriComponentsCharMap[50][52] = true // $ '%24'
-uriComponentsCharMap[50][54] = true // & '%26'
-uriComponentsCharMap[50][66] = true // + '%2B'
-uriComponentsCharMap[50][98] = true // + '%2b'
-uriComponentsCharMap[50][67] = true // , '%2C'
-uriComponentsCharMap[50][99] = true // , '%2c'
-uriComponentsCharMap[50][70] = true // / '%2F'
-uriComponentsCharMap[50][102] = true // / '%2f'
-
-uriComponentsCharMap[51] = new Array(103).fill(0x00)
-uriComponentsCharMap[51][65] = true // : '%3A'
-uriComponentsCharMap[51][97] = true // : '%3a'
-uriComponentsCharMap[51][66] = true // ; '%3B'
-uriComponentsCharMap[51][98] = true // ; '%3b'
-uriComponentsCharMap[51][68] = true // = '%3D'
-uriComponentsCharMap[51][100] = true // = '%3d'
-uriComponentsCharMap[51][70] = true // ? '%3F'
-uriComponentsCharMap[51][102] = true // ? '%3f'
+function decodeComponentChar (highCharCode, lowCharCode) {
+  if (highCharCode === 50) {
+    if (lowCharCode === 53) return '%'
 
-uriComponentsCharMap[52] = new Array(49).fill(0x00)
-uriComponentsCharMap[52][48] = true // @ '%40'
+    if (lowCharCode === 51) return '#'
+    if (lowCharCode === 52) return '$'
+    if (lowCharCode === 54) return '&'
+    if (lowCharCode === 66) return '+'
+    if (lowCharCode === 98) return '+'
+    if (lowCharCode === 67) return ','
+    if (lowCharCode === 99) return ','
+    if (lowCharCode === 70) return '/'
+    if (lowCharCode === 102) return '/'
+    return null
+  }
+  if (highCharCode === 51) {
+    if (lowCharCode === 65) return ':'
+    if (lowCharCode === 97) return ':'
+    if (lowCharCode === 66) return ';'
+    if (lowCharCode === 98) return ';'
+    if (lowCharCode === 68) return '='
+    if (lowCharCode === 100) return '='
+    if (lowCharCode === 70) return '?'
+    if (lowCharCode === 102) return '?'
+    return null
+  }
+  if (highCharCode === 52 && lowCharCode === 48) {
+    return '@'
+  }
+  return null
+}
 
-function sanitizeUrl (url, customDecoder) {
-  let originPath = url
+function safeDecodeURI (path) {
   let shouldDecode = false
-  let containsEncodedComponents = false
-  let highChar
-  let lowChar
-  for (var i = 0, len = url.length; i < len; i++) {
-    var charCode = url.charCodeAt(i)
 
-    if (shouldDecode && !containsEncodedComponents) {
-      if (highChar === 0 && uriComponentsCharMap[charCode]) {
-        highChar = charCode
-        lowChar = 0x00
-      } else if (highChar && lowChar === 0 && uriComponentsCharMap[highChar][charCode]) {
-        containsEncodedComponents = true
+  for (let i = 1; i < path.length; i++) {
+    const charCode = path.charCodeAt(i)
+
+    if (charCode === 37) {
+      const highCharCode = path.charCodeAt(i + 1)
+      const lowCharCode = path.charCodeAt(i + 2)
+
+      if (decodeComponentChar(highCharCode, lowCharCode) === null) {
+        shouldDecode = true
       } else {
-        highChar = undefined
-        lowChar = undefined
+        // %25 - encoded % char. We need to encode one more time to prevent double decoding
+        if (highCharCode === 50 && lowCharCode === 53) {
+          shouldDecode = true
+          path = path.slice(0, i + 1) + '25' + path.slice(i + 1)
+          i += 2
+        }
+        i += 2
       }
-    }
-
     // Some systems do not follow RFC and separate the path and query
     // string with a `;` character (code 59), e.g. `/foo;jsessionid=123456`.
     // Thus, we need to split on `;` as well as `?` and `#`.
-    if (charCode === 63 || charCode === 59 || charCode === 35) {
-      originPath = url.slice(0, i)
+    } else if (charCode === 63 || charCode === 59 || charCode === 35) {
+      path = path.slice(0, i)
       break
-    } else if (charCode === 37) {
-      shouldDecode = true
-      highChar = 0x00
     }
   }
-  const decoded = shouldDecode ? decodeURI(originPath) : originPath
+  return shouldDecode ? decodeURI(path) : path
+}
 
-  return {
-    path: decoded,
-    originPath,
-    sliceParameter: containsEncodedComponents
-      ? sliceAndDecode
-      : slicePath
-  }
+function safeDecodeURIComponent (uriComponent, startIndex = 0) {
+  let decoded = ''
+  let lastIndex = startIndex
 
-  function sliceAndDecode (from, to) {
-    return (customDecoder || fastDecode)(this.originPath.slice(from, to))
-  }
-}
+  for (let i = startIndex; i < uriComponent.length; i++) {
+    if (uriComponent.charCodeAt(i) === 37) {
+      const highCharCode = uriComponent.charCodeAt(i + 1)
+      const lowCharCode = uriComponent.charCodeAt(i + 2)
 
-module.exports = sanitizeUrl
+      const decodedChar = decodeComponentChar(highCharCode, lowCharCode)
+      decoded += uriComponent.slice(lastIndex, i) + decodedChar
 
-function slicePath (from, to) {
-  return this.path.slice(from, to)
+      lastIndex = i + 3
+    }
+  }
+  return uriComponent.slice(0, startIndex) + decoded + uriComponent.slice(lastIndex)
 }
+
+module.exports = { safeDecodeURI, safeDecodeURIComponent }
diff --git a/package.json b/package.json
index 65bc053..45410af 100644
--- a/package.json
+++ b/package.json
@@ -47,7 +47,6 @@
     "tsd": "^0.13.1"
   },
   "dependencies": {
-    "fast-decode-uri-component": "^1.0.1",
     "fast-deep-equal": "^3.1.3",
     "safe-regex2": "^2.0.0"
   },


Test patch:
diff --git a/test/custom-decode-uri.test.js b/test/custom-decode-uri.test.js
index b00b6da..14c12ec 100644
--- a/test/custom-decode-uri.test.js
+++ b/test/custom-decode-uri.test.js
@@ -38,7 +38,7 @@ test('decodeUriParameters called when needed 2', t => {
   const results = [
     'ci%40o',
     'foo%23bar',
-    '%23%F'
+    '%23🍌'
   ]
   const findMyWay = FindMyWay({
     decodeUriParameters: (stringToDecode) => {
diff --git a/test/issue-234.test.js b/test/issue-234.test.js
new file mode 100644
index 0000000..29cafbc
--- /dev/null
+++ b/test/issue-234.test.js
@@ -0,0 +1,95 @@
+'use strict'
+
+const t = require('tap')
+const test = t.test
+const FindMyWay = require('..')
+
+test('Match static url without encoding option', t => {
+  t.plan(2)
+
+  const findMyWay = FindMyWay()
+
+  const handler = () => {}
+
+  findMyWay.on('GET', '/🍌', handler)
+
+  t.same(findMyWay.find('GET', '/🍌').handler, handler)
+  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C').handler, handler)
+})
+
+test('Match parametric url with encoding option', t => {
+  t.plan(2)
+
+  const findMyWay = FindMyWay()
+
+  findMyWay.on('GET', '/🍌/:param', () => {})
+
+  t.same(findMyWay.find('GET', '/🍌/@').params, { param: '@' })
+  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/@').params, { param: '@' })
+})
+
+test('Match encoded parametric url with encoding option', t => {
+  t.plan(2)
+
+  const findMyWay = FindMyWay()
+
+  findMyWay.on('GET', '/🍌/:param', () => {})
+
+  t.same(findMyWay.find('GET', '/🍌/%23').params, { param: '#' })
+  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/%23').params, { param: '#' })
+})
+
+test('Decode url components', t => {
+  t.plan(3)
+
+  const findMyWay = FindMyWay()
+
+  findMyWay.on('GET', '/:param1/:param2', () => {})
+
+  t.same(findMyWay.find('GET', '/foo%23bar/foo%23bar').params, { param1: 'foo#bar', param2: 'foo#bar' })
+  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/%F0%9F%8D%8C').params, { param1: '🍌', param2: '🍌' })
+  t.same(findMyWay.find('GET', '/%F0%9F%8D%8C/foo%23bar').params, { param1: '🍌', param2: 'foo#bar' })
+})
+
+test('Decode url components', t => {
+  t.plan(5)
+
+  const findMyWay = FindMyWay()
+
+  findMyWay.on('GET', '/foo🍌bar/:param1/:param2', () => {})
+  findMyWay.on('GET', '/user/:id', () => {})
+
+  t.same(findMyWay.find('GET', '/foo%F0%9F%8D%8Cbar/foo%23bar/foo%23bar').params, { param1: 'foo#bar', param2: 'foo#bar' })
+  t.same(findMyWay.find('GET', '/user/maintainer+tomas').params, { id: 'maintainer+tomas' })
+  t.same(findMyWay.find('GET', '/user/maintainer%2Btomas').params, { id: 'maintainer+tomas' })
+  t.same(findMyWay.find('GET', '/user/maintainer%20tomas').params, { id: 'maintainer tomas' })
+  t.same(findMyWay.find('GET', '/user/maintainer%252Btomas').params, { id: 'maintainer%2Btomas' })
+})
+
+test('Decode url components', t => {
+  t.plan(18)
+
+  const findMyWay = FindMyWay()
+
+  findMyWay.on('GET', '/:param1', () => {})
+  t.same(findMyWay.find('GET', '/foo%23bar').params, { param1: 'foo#bar' })
+  t.same(findMyWay.find('GET', '/foo%24bar').params, { param1: 'foo$bar' })
+  t.same(findMyWay.find('GET', '/foo%26bar').params, { param1: 'foo&bar' })
+  t.same(findMyWay.find('GET', '/foo%2bbar').params, { param1: 'foo+bar' })
+  t.same(findMyWay.find('GET', '/foo%2Bbar').params, { param1: 'foo+bar' })
+  t.same(findMyWay.find('GET', '/foo%2cbar').params, { param1: 'foo,bar' })
+  t.same(findMyWay.find('GET', '/foo%2Cbar').params, { param1: 'foo,bar' })
+  t.same(findMyWay.find('GET', '/foo%2fbar').params, { param1: 'foo/bar' })
+  t.same(findMyWay.find('GET', '/foo%2Fbar').params, { param1: 'foo/bar' })
+
+  t.same(findMyWay.find('GET', '/foo%3abar').params, { param1: 'foo:bar' })
+  t.same(findMyWay.find('GET', '/foo%3Abar').params, { param1: 'foo:bar' })
+  t.same(findMyWay.find('GET', '/foo%3bbar').params, { param1: 'foo;bar' })
+  t.same(findMyWay.find('GET', '/foo%3Bbar').params, { param1: 'foo;bar' })
+  t.same(findMyWay.find('GET', '/foo%3dbar').params, { param1: 'foo=bar' })
+  t.same(findMyWay.find('GET', '/foo%3Dbar').params, { param1: 'foo=bar' })
+  t.same(findMyWay.find('GET', '/foo%3fbar').params, { param1: 'foo?bar' })
+  t.same(findMyWay.find('GET', '/foo%3Fbar').params, { param1: 'foo?bar' })
+
+  t.same(findMyWay.find('GET', '/foo%40bar').params, { param1: 'foo@bar' })
+})