Add apiVersion to client config (#18)

* Add apiVersion to client config

* Add YYYY-MM-DD format to docstring

Author: Will Myers

CHANGELOG.md

@@ -1,18 +1,21 @@
+Current Version
+  - Add apiVersion to client config
+
 2.4.0 June 12, 2017
- - Request errors now include the `response` object.
+  - Request errors now include the `response` object.
 
 2.3.0 January 6, 2017
- - Add `merchants` resource
-     + `merchants#all`
+  - Add `merchants` resource
+    + `merchants#all`
 
 2.2.0 January 4, 2017
- - Add `client.utils.isWebhookAuthentic` function
+  - Add `client.utils.isWebhookAuthentic` function
 
 2.1.1 October 12, 2016
- - Renamed package to `@button/button-client-node`
+  - Renamed package to `@button/button-client-node`
 
 2.1.0 September 12, 2016
- - Added config.hostname, config.port, and config.secure
+  - Added config.hostname, config.port, and config.secure
 
 2.0.0 August 24, 2016
   - Added `accounts` resource

index.js

@@ -13,6 +13,16 @@ var configDefaults = {
   timeout: false
 };
 
+function headers(apiVersion) {
+  const nodeVersion = process.versions.node;
+  const userAgent = 'button-client-node/' + version + ' node/' + nodeVersion;
+
+  return merge(compact({ 'X-Button-API-Version': apiVersion }), {
+    'Content-Type': 'application/json',
+    'User-Agent': userAgent
+  });
+}
+
 function client(apiKey, config) {
   //
   // #client provides the top-level interface to making API requests to Button.
@@ -26,6 +36,8 @@ function client(apiKey, config) {
   // @param {bool=} config.secure will use HTTPS if true and HTTP if false
   // @param {number=} config.timeout a timeout in ms to abort API calls
   // @param {Func=} config.promise a function which should return a promise
+  // @param {string=} config.apiVersion a string pinning your API version for
+  //   the request (YYYY-MM-DD)
   // @returns {Object} a client
   //
   if (!apiKey) {
@@ -44,10 +56,7 @@ function client(apiKey, config) {
 
   var requestOptions = merge(requestConfig, {
     auth: apiKey + ':',
-    headers: {
-      'Content-Type': 'application/json',
-      'User-Agent': 'button-client-node/' + version + ' node/' + process.versions.node
-    }
+    headers: headers(config.apiVersion)
   });
 
   var maybePromiseRequest = maybePromise(

test/index-test.js

@@ -37,8 +37,9 @@ describe('client', function() {
     it('defaults config options', function(done) {
       var c = client('sk-XXX').orders;
       var orderId = 'btnorder-XXX';
-      var scope = nock('https://api.usebutton.com:443')
-        .get('/v1/order/' + orderId)
+      var scope = nock('https://api.usebutton.com:443', {
+        badheaders: ['x-button-api-version']
+      }).get('/v1/order/' + orderId)
         .reply(200, { meta: { status: 'ok' }, 'object': {} });
 
       c.get(orderId, function(err) {
@@ -90,6 +91,23 @@ describe('client', function() {
       }.bind(this));
     });
 
+    it('sets the API Version', function(done) {
+      var c = client('sk-XXX', { apiVersion: '2017-01-01' }).orders;
+      var orderId = 'btnorder-XXX';
+      var scope = nock('https://api.usebutton.com', {
+        reqheaders: {
+          'x-button-api-version': '2017-01-01'
+        }
+      }).get('/v1/order/' + orderId)
+        .reply(200, { meta: { status: 'ok' }, 'object': {} });
+
+      c.get(orderId, function(err) {
+        expect(err).to.be(null);
+        scope.done();
+        done();
+      }.bind(this));
+    });
+
   });
 
 });