From 535e6fcca62d76c32e345e71a3060f2a458800f3 Mon Sep 17 00:00:00 2001
From: Mike Reinstein <reinstein.mike@gmail.com>
Date: Fri, 4 May 2018 09:27:16 -0700
Subject: [PATCH] return a Promise when no callback function is specified. #35

---
 README.md     | 15 ++++++++++++++-
 index.js      | 18 ++++++++++++++++--
 test/index.js | 43 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 73 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index 61e31e1..552a848 100644
--- a/README.md
+++ b/README.md
@@ -22,13 +22,26 @@ This module provides a function to handle this validation.
 
 ### usage
 
+You may include a callback function, in the standard node error argument-first format:
+
+```javascript
+const verifier = require('alexa-verifier')
+
+
+verifier(cert_url, signature, requestRawBody, function callbackFn(er) {
+  // if er, something went wrong
+})
+```
+
+Ommiting a callback function returns a promise:
 ```javascript
 const verifier = require('alexa-verifier')
 
 
-verifier(cert_url, signature, requestRawBody, callback)
+const verifyPromise = verifier(cert_url, signature, requestRawBody, callback)
 ```
 
+
 * `cert_url`  full url of the certificate to verify (from HTTP request header named `signaturecertchainurl`)
 * `signature` signature of the request (from HTTP request header named `signature`)
 * `requestRawBody`  full body string from POST request
diff --git a/index.js b/index.js
index 7f8c6c1..8eac4d2 100644
--- a/index.js
+++ b/index.js
@@ -61,8 +61,7 @@ function validateTimestamp (requestBody) {
 }
 
 
-// certificate validator express middleware for amazon echo
-module.exports = function verifier (cert_url, signature, requestBody, callback) {
+function verifier (cert_url, signature, requestBody, callback) {
   var er
 
   if(!cert_url)
@@ -92,3 +91,18 @@ module.exports = function verifier (cert_url, signature, requestBody, callback)
     callback()
   })
 }
+
+
+// certificate validator for amazon echo
+module.exports = function (cert_url, signature, requestBody, cb) {
+  if(cb)
+    return verifier(cert_url, signature, requestBody, cb)
+
+  return new Promise(function( resolve, reject) {
+     verifier(cert_url, signature, requestBody, function(er) {
+        if(er)
+          return reject(er)
+        resolve()
+     })
+  })
+}
diff --git a/test/index.js b/test/index.js
index aadcc5b..7fe50c5 100644
--- a/test/index.js
+++ b/test/index.js
@@ -197,3 +197,46 @@ test('handle valid signature with double byte utf8 encodings', function (t) {
     t.end()
   })
 })
+
+
+test('invocation', function (t) {
+  var ts = '2017-04-05T12:02:36Z'
+  var now = new Date(ts)
+  var clock = sinon.useFakeTimers(now.getTime())
+  var cert_url = 'https://s3.amazonaws.com/echo.api/echo-api-cert-4.pem'
+  var signature = 'Qc8OuaGEHWeL/39XTEDYFbOCufYWpwi45rqmM2R4WaSEYcSXq+hUko/88wv48+6SPUiEddWSEEINJFAFV5auYZsnBzqCK+SO8mGNOGHmLYpcFuSEHI3eA3nDIEARrXTivqqbH/LCPJHc0tqNYr3yPZRIR2mYFndJOxgDNSOooZX+tp2GafHHsjjShCjmePaLxJiGG1DmrL6fyOJoLrzc0olUxLmnJviS6Q5wBir899TMEZ/zX+aiBTt/khVvwIh+hI/PZsRq/pQw4WAvQz1bcnGNamvMA/TKSJtR0elJP+TgCqbVoYisDgQXkhi8/wonkLhs68pN+TurbR7GyC1vxw=='
+  var body = {
+    "version": "1.0",
+    "session": {
+      "new": true,
+      "sessionId": "SessionId.7745e45d-3042-45eb-8e86-cab2cf285daf",
+      "application": {
+        "applicationId": "amzn1.ask.skill.75c997b8-610f-4eb4-bf2e-95810e15fba2"
+      },
+      "attributes": {},
+      "user": {
+        "userId": "amzn1.ask.account.AF6Z7574YHBQCNNTJK45QROUSCUJEHIYAHZRP35FVU673VDGDKV4PH2M52PX4XWGCSYDM66B6SKEEFJN6RYWN7EME3FKASDIG7DPNGFFFNTN4ZT6B64IIZKSNTXQXEMVBXMA7J3FN3ERT2A4EDYFUYMGM4NSQU4RTAQOZWDD2J7JH6P2ROP2A6QEGLNLZDXNZU2DL7BKGCVLMNA"
+      }
+    },
+    "request": {
+      "type": "IntentRequest",
+      "requestId": "EdwRequestId.fa7428b7-75d0-44c8-aebb-4c222ed48ebe",
+      "timestamp": ts,
+      "locale": "en-US",
+      "intent": {
+        "name": "HelloWorld"
+      },
+      "inDialog": false
+    }
+  }
+
+  var result = verifier(cert_url, signature, JSON.stringify(body))
+  result.catch(function(er) { })
+  t.assert(result instanceof Promise, 'omitting callback returns a promise')
+
+  var callbackResult = verifier(cert_url, signature, JSON.stringify(body), function(er) { })
+
+  t.equal(callbackResult, undefined, 'including callback does not return a promise')
+
+  t.end()
+})