Promise API and consistent callback function signature

.eslintignore

@@ -0,0 +1,3 @@
+node_modules
+examples
+test

.eslintrc.yaml

@@ -0,0 +1,136 @@
+root: true
+extends: eslint:recommended
+parserOptions:
+  ecmaVersion: 6
+  ecmaFeatures:
+    impliedStrict: true
+  sourceType: module
+env:
+  es6: true
+  node: true
+  mocha: true
+  jasmine: true
+rules:
+  linebreak-style:
+    - error
+    - unix
+  max-len:
+    - warn
+    - code: 80
+      tabWidth: 2
+      ignoreComments: true
+      ignoreUrls: true
+  indent:
+    - error
+    - 2
+    - SwitchCase: 1
+      VariableDeclarator:
+        let: 2
+        const: 3
+  semi:
+    - error
+    - always
+  consistent-this:
+    - error
+    - self
+    - $ctrl
+  quotes:
+    - error
+    - single
+    - allowTemplateLiterals: true
+  curly:
+    - error
+    - all
+  comma-dangle:
+    - error
+    - always-multiline
+  new-cap:
+    - error
+    - newIsCap: true
+      capIsNew: true
+      properties: false
+  array-bracket-spacing:
+    - error
+    - never
+  arrow-spacing:
+    - error
+    - before: true
+      after: true
+  block-spacing:
+    - error
+    - always
+  comma-spacing:
+    - error
+    - before: false
+      after: true
+  computed-property-spacing:
+    - error
+    - never
+  generator-star-spacing:
+    - error
+    - before: true
+      after: false
+  key-spacing:
+    - error
+    - beforeColon: false
+      afterColon: true
+      mode: minimum
+  keyword-spacing:
+    - error
+    - before: true
+  semi-spacing:
+    - error
+    - before: false
+      after: true
+  space-in-parens:
+    - error
+    - never
+  space-unary-ops:
+    - error
+    - words: true
+      nonwords: false
+  space-before-function-paren:
+    - error
+    - never
+  space-before-blocks:
+    - error
+    - always
+  yoda:
+    - error
+    - never
+  wrap-iife:
+    - error
+    - outside
+  eqeqeq:
+    - error
+    - always
+  newline-per-chained-call:
+    - error
+    - ignoreChainWithDepth: 3
+  one-var-declaration-per-line:
+    - error
+    - initializations
+  brace-style:
+    - error
+    - stroustrup
+  no-implicit-coercion:
+    - error
+    - boolean: false
+  no-multiple-empty-lines:
+    - error
+    - max: 1
+  eol-last: error
+  dot-notation: error
+  space-infix-ops: error
+  no-with: error
+  no-unreachable: error
+  no-redeclare: error
+  no-unexpected-multiline: error
+  no-multi-spaces: error
+  no-multi-str: error
+  no-trailing-spaces: error
+  no-mixed-spaces-and-tabs: error
+  no-spaced-func: error
+  no-whitespace-before-property: error
+  no-lonely-if: error
+  no-console: off

README.md

@@ -71,19 +71,20 @@ The following is the minimum needed code to send an email with the [/mail/send H
 
 ```javascript
   var helper = require('sendgrid').mail
-  from_email = new helper.Email("[email protected]")
-  to_email = new helper.Email("[email protected]")
-  subject = "Hello World from the SendGrid Node.js Library!"
-  content = new helper.Content("text/plain", "Hello, Email!")
+  from_email = new helper.Email('[email protected]')
+  to_email = new helper.Email('[email protected]')
+  subject = 'Hello World from the SendGrid Node.js Library!'
+  content = new helper.Content('text/plain', 'Hello, Email!')
   mail = new helper.Mail(from_email, subject, to_email, content)
 
-  var sg = require('sendgrid').SendGrid(process.env.SENDGRID_API_KEY)
-  var requestBody = mail.toJSON()
-  var request = sg.emptyRequest()
-  request.method = 'POST'
-  request.path = '/v3/mail/send'
-  request.body = requestBody
-  sg.API(request, function (response) {
+  var sg = require('sendgrid')(process.env.SENDGRID_API_KEY);
+  var request = sg.emptyRequest({
+    method: 'POST',
+    path: '/v3/mail/send',
+    body: mail.toJSON()
+  });
+
+  sg.API(request, function(error, response) {
     console.log(response.statusCode)
     console.log(response.body)
     console.log(response.headers)
@@ -97,48 +98,86 @@ The `Mail` constructor creates a [personalization object](https://sendgrid.com/d
 The following is the minimum needed code to send an email without the /mail/send Helper ([here](https://github.com/sendgrid/sendgrid-nodejs/blob/master/examples/mail/mail.js#L31) is a full example):
 
 ```javascript
-var sg = require('sendgrid').SendGrid(process.env.SENDGRID_API_KEY)
-var request = sg.emptyRequest()
-request.body = {
-  "personalizations": [
-    {
-      "to": [
-        {
-          "email": "[email protected]"
-        }
-      ],
-      "subject": "Hello World from the SendGrid Node.js Library!"
-    }
-  ],
-  "from": {
-    "email": "[email protected]"
-  },
-  "content": [
-    {
-      "type": "text/plain",
-      "value": "Hello, Email!"
-    }
-  ]
-};
-request.method = 'POST'
-request.path = '/v3/mail/send'
-sg.API(request, function (response) {
-  console.log(response.statusCode)
-  console.log(response.body)
-  console.log(response.headers)
-})
+var sg = require('sendgrid')(process.env.SENDGRID_API_KEY);
+var request = sg.emptyRequest({
+  method: 'POST',
+  path: '/v3/mail/send',
+  body: {
+    personalizations: [
+      {
+        to: [
+          {
+            email: '[email protected]'
+          }
+        ],
+        subject: 'Hello World from the SendGrid Node.js Library!'
+      }
+    ],
+    from: {
+      email: '[email protected]'
+    },
+    content: [
+      {
+        type: 'text/plain',
+        value: 'Hello, Email!'
+      }
+    ]
+  };
+});
+
+//With promise
+sg.API(request)
+  .then(response => {
+    console.log(response.statusCode);
+    console.log(response.body);
+    console.log(response.headers);
+  })
+  .catch(error => {
+    //error is an instance of SendGridError
+    //The full response is attached to error.response
+    console.log(error.response.statusCode);
+  });
+
+//With callback
+sg.API(request, function(error, response) {
+  if (error) {
+    console.log('Error response received');
+  }
+  console.log(response.statusCode);
+  console.log(response.body);
+  console.log(response.headers);
+});
 ```
 
 ## General v3 Web API Usage
 
 ```javascript
-var sg = require('sendgrid').SendGrid(process.env.SENDGRID_API_KEY)
+var sg = require('sendgrid')(process.env.SENDGRID_API_KEY)
 
 // GET Collection
-var request = sg.emptyRequest()
-request.method = 'GET'
-request.path = '/v3/api_keys'
-sg.API(request, function (response) {
+var request = sg.emptyRequest({
+  method: 'GET',
+  path: '/v3/api_keys'
+});
+
+//With promise
+sg.API(request)
+  .then(response => {
+    console.log(response.statusCode)
+    console.log(response.body)
+    console.log(response.headers)
+  })
+  .catch(error => {
+    //error is an instance of SendGridError
+    //The full response is attached to error.response
+    console.log(error.response.statusCode);
+  });
+
+//With callback
+sg.API(request, function(error, response) {
+  if (error) {
+    console.log('Error response received');
+  }
   console.log(response.statusCode)
   console.log(response.body)
   console.log(response.headers)

TROUBLESHOOTING.md

@@ -73,13 +73,13 @@ To read the error message returned by SendGrid's API:
   content = new helper.Content("text/plain", "Hello, Email!")
   mail = new helper.Mail(from_email, subject, to_email, content)
 
-  var sg = require('sendgrid').SendGrid(process.env.SENDGRID_API_KEY)
+  var sg = require('sendgrid')(process.env.SENDGRID_API_KEY)
   var requestBody = mail.toJSON()
   var request = sg.emptyRequest()
   request.method = 'POST'
   request.path = '/v3/mail/send'
   request.body = requestBody
-  sg.API(request, function (response) {
+  sg.API(request, function (error, response) {
     console.log(response.statusCode)
     console.log(response.body)
     console.log(response.headers)