Make it work with Async Hooks

HISTORY.md

@@ -8,6 +8,7 @@ unreleased
     - deps: http-errors@1.7.3
   * deps: safe-buffer@5.2.0
   * deps: type-is@~1.6.18
+  * Make it work with Async Hooks
 
 1.19.0 / 2019-04-25
 ===================

lib/read.js

@@ -73,30 +73,35 @@ function read (req, res, next, parse, debug, options) {
   }
 
   // read body
-  debug('read body')
-  getBody(stream, opts, function (error, body) {
-    if (error) {
-      var _error
-
-      if (error.type === 'encoding.unsupported') {
-        // echo back charset
-        _error = createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
-          charset: encoding.toLowerCase(),
-          type: 'charset.unsupported'
-        })
-      } else {
-        // set status code on error
-        _error = createError(400, error)
-      }
+  function readErrorHandler (error) {
+    var _error
+    if (error.type === 'encoding.unsupported') {
+      // echo back charset
+      _error = createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
+        charset: encoding.toLowerCase(),
+        type: 'charset.unsupported'
+      })
+    } else {
+      // set status code on error
+      _error = createError(400, error)
+    }
 
-      // read off entire request
-      stream.resume()
-      onFinished(req, function onfinished () {
+    // read off entire request
+    stream.resume()
+    if (isPromiseAvailable()) {
+      new Promise(function (resolve) {
+        onFinished(req, resolve)
+      }).then(function () {
+        next(createError(400, _error))
+      })
+    } else {
+      onFinished(req, function () {
         next(createError(400, _error))
       })
-      return
     }
+  }
 
+  function readSuccessHandler (body) {
     // verify
     if (verify) {
       try {
@@ -128,7 +133,20 @@ function read (req, res, next, parse, debug, options) {
     }
 
     next()
-  })
+  }
+
+  debug('read body')
+  if (isPromiseAvailable()) {
+    getBody(stream, opts)
+      .then(readSuccessHandler, readErrorHandler)
+  } else {
+    getBody(stream, opts, function (error, body) {
+      if (error) {
+        return readErrorHandler(error)
+      }
+      readSuccessHandler(body)
+    })
+  }
 }
 
 /**
@@ -179,3 +197,14 @@ function contentstream (req, debug, inflate) {
 
   return stream
 }
+
+/**
+ * Check whether Promise is available.
+ *
+ * @return {boolean}
+ * @private
+ */
+
+function isPromiseAvailable () {
+  return typeof global.Promise === 'function'
+}

test/body-parser.js

@@ -3,6 +3,13 @@ var http = require('http')
 var methods = require('methods')
 var request = require('supertest')
 
+var describeWhenAsyncHooksAreSupported = describe.skip
+try {
+  var asyncHooks = require('async_hooks')
+  describeWhenAsyncHooksAreSupported = typeof asyncHooks.AsyncLocalStorage === 'function' ? describe : describe.skip
+} catch (ignored) {
+}
+
 var bodyParser = require('..')
 
 describe('bodyParser()', function () {
@@ -51,6 +58,57 @@ describe('bodyParser()', function () {
       .expect(200, '{"user":"tobi"}', done)
   })
 
+  describeWhenAsyncHooksAreSupported('used with async hooks', function () {
+    it('should maintain context when parsing was successful', function (done) {
+      var _bodyParser = bodyParser()
+      var asyncLocalStorage = new asyncHooks.AsyncLocalStorage()
+
+      var server = http.createServer(function (req, res) {
+        const store = {
+          contextMaintained: true
+        }
+        asyncLocalStorage.run(store, function () {
+          _bodyParser(req, res, function (err) {
+            res.statusCode = err ? (err.status || 500) : 200
+            res.end(err ? err.message : JSON.stringify(asyncLocalStorage.getStore()))
+          })
+        })
+      })
+
+      request(server)
+        .post('/')
+        .set('Content-Type', 'application/json')
+        .send('{"user":"tobi"}')
+        .expect(200, '{"contextMaintained":true}', done)
+    })
+
+    it('should maintain context when parsing has failed', function (done) {
+      var _bodyParser = bodyParser.text()
+      var asyncLocalStorage = new asyncHooks.AsyncLocalStorage()
+
+      var server = http.createServer(function (req, res) {
+        const store = {
+          contextMaintained: true
+        }
+        asyncLocalStorage.run(store, function () {
+          _bodyParser(req, res, function (err) {
+            if (!err) {
+              res.statusCode = 500
+              res.end('parsing was expeced to fail, but it succeeded')
+            }
+            res.end(JSON.stringify(asyncLocalStorage.getStore()))
+          })
+        })
+      })
+
+      request(server)
+        .post('/')
+        .set('Content-Type', 'text/plain; charset=x-fake')
+        .send('user is tobi')
+        .expect(200, '{"contextMaintained":true}', done)
+    })
+  })
+
   describe('http methods', function () {
     before(function () {
       var _bodyParser = bodyParser()