Modernize ES5 to ES6 with lebab (#607)

* Add lebab and a script to run it

* lebab transform: arrow

* lebab transform: arg-rest

* lebab transform: arg-spread

* lebab transform: obj-method

* lebab transform: obj-shorthand

* lebab transform: let

* lebab transform: template

* lebab transform: default-param

* lebab transform: destruct-param

* lebab transform: includes

* Revert "Add lebab and a script to run it"

This reverts commit 70fd492.

* Revert "lebab transform: destruct-param" because its changes didn't seem good.

This  reverts commit b56f52d.

* Revert "lebab transform: default-param" because it seems dangerous / backwards-incompatible.

This reverts commit 7eba992.

* Unrelated: mark 8.1 as minimum 8-series version

* Add mocha-only script

* Use arrows in more places

* Loosen some eslint rules I don't love

.eslintrc.js

@@ -7,7 +7,6 @@ module.exports = {
     'accessor-pairs': 'error',
     'array-bracket-spacing': ['error', 'never'],
     'array-callback-return': 'off',
-    'arrow-body-style': 'error',
     'arrow-parens': 'error',
     'arrow-spacing': 'error',
     'block-scoped-var': 'off',
@@ -43,7 +42,7 @@ module.exports = {
     'func-call-spacing': 'error',
     'func-name-matching': 'error',
     'func-names': 'off',
-    'func-style': ['error', 'declaration'],
+    'func-style': ['error', 'declaration', {allowArrowFunctions: true}],
     'generator-star-spacing': 'error',
     'global-require': 'off',
     'guard-for-in': 'off',

.travis.yml

@@ -1,8 +1,11 @@
 language: node_js
+cache:
+  yarn: true
+  directories:
+    - node_modules
 node_js:
-  - "6"
-  - "8"
-  - "9"
-  - "10"
+  - '6'
+  - '8'
+  - '10'
 sudo: false
-after_success: npm run report && npm run coveralls
+after_success: yarn report && yarn coveralls

examples/webhook-signing/express.js

@@ -37,6 +37,6 @@ app.post(
   }
 );
 
-app.listen(3000, function() {
+app.listen(3000, () => {
   console.log('Example app listening on port 3000!');
 });

lib/Error.js

@@ -1,14 +1,14 @@
 'use strict';
 
-var utils = require('./utils');
+const utils = require('./utils');
 
 module.exports = _Error;
 
 /**
  * Generic Error klass to wrap any errors returned by stripe-node
  */
 function _Error(raw) {
-  this.populate.apply(this, arguments);
+  this.populate(...arguments);
   this.stack = new Error(this.message).stack;
 }
 
@@ -27,9 +27,9 @@ _Error.extend = utils.protoExtend;
  * Create subclass of internal Error klass
  * (Specifically for errors returned from Stripe's REST API)
  */
-var StripeError = (_Error.StripeError = _Error.extend({
+const StripeError = (_Error.StripeError = _Error.extend({
   type: 'StripeError',
-  populate: function(raw) {
+  populate(raw) {
     // Move from prototype def (so it appears in stringified obj)
     this.type = this.type;
 
@@ -49,7 +49,7 @@ var StripeError = (_Error.StripeError = _Error.extend({
 /**
  * Helper factory which takes raw stripe errors and outputs wrapping instances
  */
-StripeError.generate = function(rawStripeError) {
+StripeError.generate = (rawStripeError) => {
   switch (rawStripeError.type) {
     case 'card_error':
       return new _Error.StripeCardError(rawStripeError);

lib/MultipartDataGenerator.js

@@ -1,51 +1,50 @@
 'use strict';
 
-var Buffer = require('safe-buffer').Buffer;
-var utils = require('./utils');
+const Buffer = require('safe-buffer').Buffer;
+const utils = require('./utils');
 
 // Method for formatting HTTP body for the multipart/form-data specification
 // Mostly taken from Fermata.js
 // https://github.com/natevw/fermata/blob/5d9732a33d776ce925013a265935facd1626cc88/fermata.js#L315-L343
 function multipartDataGenerator(method, data, headers) {
-  var segno = (
+  const segno = (
     Math.round(Math.random() * 1e16) + Math.round(Math.random() * 1e16)
   ).toString();
-  headers['Content-Type'] = 'multipart/form-data; boundary=' + segno;
-  var buffer = Buffer.alloc(0);
+  headers['Content-Type'] = `multipart/form-data; boundary=${segno}`;
+  let buffer = Buffer.alloc(0);
 
   function push(l) {
-    var prevBuffer = buffer;
-    var newBuffer = l instanceof Buffer ? l : Buffer.from(l);
+    const prevBuffer = buffer;
+    const newBuffer = l instanceof Buffer ? l : Buffer.from(l);
     buffer = Buffer.alloc(prevBuffer.length + newBuffer.length + 2);
     prevBuffer.copy(buffer);
     newBuffer.copy(buffer, prevBuffer.length);
     buffer.write('\r\n', buffer.length - 2);
   }
 
   function q(s) {
-    return '"' + s.replace(/"|"/g, '%22').replace(/\r\n|\r|\n/g, ' ') + '"';
+    return `"${s.replace(/"|"/g, '%22').replace(/\r\n|\r|\n/g, ' ')}"`;
   }
 
-  for (var k in utils.flattenAndStringify(data)) {
-    var v = data[k];
-    push('--' + segno);
+  for (const k in utils.flattenAndStringify(data)) {
+    const v = data[k];
+    push(`--${segno}`);
     if (v.hasOwnProperty('data')) {
       push(
-        'Content-Disposition: form-data; name=' +
-          q(k) +
-          '; filename=' +
-          q(v.name || 'blob')
+        `Content-Disposition: form-data; name=${q(k)}; filename=${q(
+          v.name || 'blob'
+        )}`
       );
-      push('Content-Type: ' + (v.type || 'application/octet-stream'));
+      push(`Content-Type: ${v.type || 'application/octet-stream'}`);
       push('');
       push(v.data);
     } else {
-      push('Content-Disposition: form-data; name=' + q(k));
+      push(`Content-Disposition: form-data; name=${q(k)}`);
       push('');
       push(v);
     }
   }
-  push('--' + segno + '--');
+  push(`--${segno}--`);
 
   return buffer;
 }

lib/ResourceNamespace.js

@@ -4,10 +4,10 @@
 // It also works recursively, so you could do i.e. `stripe.billing.invoicing.pay`.
 
 function ResourceNamespace(stripe, resources) {
-  for (var name in resources) {
-    var camelCaseName = name[0].toLowerCase() + name.substring(1);
+  for (const name in resources) {
+    const camelCaseName = name[0].toLowerCase() + name.substring(1);
 
-    var resource = new resources[name](stripe);
+    const resource = new resources[name](stripe);
 
     this[camelCaseName] = resource;
   }

lib/StripeMethod.basic.js

@@ -1,8 +1,8 @@
 'use strict';
 
-var isPlainObject = require('lodash.isplainobject');
-var stripeMethod = require('./StripeMethod');
-var utils = require('./utils');
+const isPlainObject = require('lodash.isplainobject');
+const stripeMethod = require('./StripeMethod');
+const utils = require('./utils');
 
 module.exports = {
   create: stripeMethod({
@@ -33,12 +33,12 @@ module.exports = {
     urlParams: ['id'],
   }),
 
-  setMetadata: function(id, key, value, auth, cb) {
-    var self = this;
-    var data = key;
-    var isObject = isPlainObject(key);
+  setMetadata(id, key, value, auth, cb) {
+    const self = this;
+    const data = key;
+    const isObject = isPlainObject(key);
     // We assume null for an empty object
-    var isNull = data === null || (isObject && !Object.keys(data).length);
+    const isNull = data === null || (isObject && !Object.keys(data).length);
 
     // Allow optional passing of auth & cb:
     if ((isNull || isObject) && typeof value == 'string') {
@@ -50,85 +50,78 @@ module.exports = {
       auth = null;
     }
 
-    var urlData = this.createUrlData();
-    var path = this.createFullPath('/' + id, urlData);
+    const urlData = this.createUrlData();
+    const path = this.createFullPath(`/${id}`, urlData);
 
     return utils.callbackifyPromiseWithTimeout(
-      new Promise(
-        function(resolve, reject) {
-          if (isNull) {
-            // Reset metadata:
-            sendMetadata(null, auth);
-          } else if (!isObject) {
-            // Set individual metadata property:
-            var metadata = {};
-            metadata[key] = value;
-            sendMetadata(metadata, auth);
-          } else {
-            // Set entire metadata object after resetting it:
-            this._request(
-              'POST',
-              null,
-              path,
-              {metadata: null},
-              auth,
-              {},
-              function(err, response) {
-                if (err) {
-                  return reject(err);
-                }
-                sendMetadata(data, auth);
+      new Promise((resolve, reject) => {
+        if (isNull) {
+          // Reset metadata:
+          sendMetadata(null, auth);
+        } else if (!isObject) {
+          // Set individual metadata property:
+          const metadata = {};
+          metadata[key] = value;
+          sendMetadata(metadata, auth);
+        } else {
+          // Set entire metadata object after resetting it:
+          this._request(
+            'POST',
+            null,
+            path,
+            {metadata: null},
+            auth,
+            {},
+            (err, response) => {
+              if (err) {
+                return reject(err);
               }
-            );
-          }
+              sendMetadata(data, auth);
+            }
+          );
+        }
 
-          function sendMetadata(metadata, auth) {
-            self._request(
-              'POST',
-              null,
-              path,
-              {metadata: metadata},
-              auth,
-              {},
-              function(err, response) {
-                if (err) {
-                  reject(err);
-                } else {
-                  resolve(response.metadata);
-                }
+        function sendMetadata(metadata, auth) {
+          self._request(
+            'POST',
+            null,
+            path,
+            {metadata},
+            auth,
+            {},
+            (err, response) => {
+              if (err) {
+                reject(err);
+              } else {
+                resolve(response.metadata);
               }
-            );
-          }
-        }.bind(this)
-      ),
+            }
+          );
+        }
+      }),
       cb
     );
   },
 
-  getMetadata: function(id, auth, cb) {
+  getMetadata(id, auth, cb) {
     if (!cb && typeof auth == 'function') {
       cb = auth;
       auth = null;
     }
 
-    var urlData = this.createUrlData();
-    var path = this.createFullPath('/' + id, urlData);
+    const urlData = this.createUrlData();
+    const path = this.createFullPath(`/${id}`, urlData);
 
     return utils.callbackifyPromiseWithTimeout(
-      new Promise(
-        function(resolve, reject) {
-          this._request('GET', null, path, {}, auth, {}, function(
-            err,
-            response
-          ) {
-            if (err) {
-              reject(err);
-            } else {
-              resolve(response.metadata);
-            }
-          });
-        }.bind(this)
-      ),
+      new Promise((resolve, reject) => {
+        this._request('GET', null, path, {}, auth, {}, (err, response) => {
+          if (err) {
+            reject(err);
+          } else {
+            resolve(response.metadata);
+          }
+        });
+      }),
       cb
     );
   },

lib/StripeMethod.js

@@ -1,8 +1,8 @@
 'use strict';
 
-var utils = require('./utils');
-var makeRequest = require('./makeRequest');
-var makeAutoPaginationMethods = require('./autoPagination')
+const utils = require('./utils');
+const makeRequest = require('./makeRequest');
+const makeAutoPaginationMethods = require('./autoPagination')
   .makeAutoPaginationMethods;
 
 /**
@@ -21,18 +21,18 @@ var makeAutoPaginationMethods = require('./autoPagination')
  */
 function stripeMethod(spec) {
   return function() {
-    var self = this;
-    var args = [].slice.call(arguments);
+    const self = this;
+    const args = [].slice.call(arguments);
 
-    var callback = typeof args[args.length - 1] == 'function' && args.pop();
+    const callback = typeof args[args.length - 1] == 'function' && args.pop();
 
-    var requestPromise = utils.callbackifyPromiseWithTimeout(
+    const requestPromise = utils.callbackifyPromiseWithTimeout(
       makeRequest(self, args, spec, {}),
       callback
     );
 
     if (spec.methodType === 'list') {
-      var autoPaginationMethods = makeAutoPaginationMethods(
+      const autoPaginationMethods = makeAutoPaginationMethods(
         self,
         args,
         spec,