Allowed disabling setting of 'UserAgent' header

refs https://github.com/TryGhost/Toolbox/issues/348
refs https://github.com/TryGhost/Toolbox/issues/301

- The behavior is symmetric to the one in Conte API SDK allowing to optionaly disable sending User-Agent header. Gives more control to the client to skip sending the header for whatever reason

Author: naz

packages/admin-api/lib/admin-api.js

@@ -41,6 +41,7 @@ const resolveAPIPrefix = (version) => {
  * @param {String} options.url
  * @param {String} [options.ghostPath]
  * @param {String|Boolean} options.version - a version string like v3.2, v4.1, v5.8 or boolean value identifying presence of Accept-Version header
+ * @param {Boolean} [options.userAgent] - flag controlling if the 'User-Agent' header should be sent with a request
  * @param {Function} [options.makeRequest]
  * @param {Function} [options.generateToken]
  */
@@ -51,6 +52,7 @@ module.exports = function GhostAdminAPI(options) {
 
     const defaultConfig = {
         ghostPath: 'ghost',
+        userAgent: true,
         generateToken: token,
         makeRequest({url, method, data, params = {}, headers = {}}) {
             return axios({
@@ -411,10 +413,13 @@ module.exports = function GhostAdminAPI(options) {
         authorizationHeader = `Ghost ${config.generateToken(key, audience)}`;
 
         const ghostHeaders = {
-            Authorization: authorizationHeader,
-            'User-Agent': `GhostAdminSDK/${packageVersion}`
+            Authorization: authorizationHeader
         };
 
+        if (config.userAgent) {
+            ghostHeaders['User-Agent'] = `GhostAdminSDK/${packageVersion}`;
+        }
+
         if (config.acceptVersionHeader) {
             ghostHeaders['Accept-Version'] = config.acceptVersionHeader;
         }

packages/admin-api/test/lib/admin-api.test.js

@@ -290,5 +290,29 @@ describe('GhostAdminAPI general', function () {
             should.equal(generateTokenSpy.args[0][0], '5c73def7a21ad85eda5d4faa:d9a3e5b2d6c2a4afb094655c4dc543220be60b3561fa9622e3891213cb4357d0');
             should.equal(generateTokenSpy.args[0][1], '/admin/');
         });
+
+        it('does not set  "User-Agent" header when disabled', async function () {
+            const makeRequestStub = sinon.stub().returns(Promise.resolve({
+                config: {}
+            }));
+            const generateTokenSpy = sinon.spy();
+
+            const api = new GhostAdminAPI({
+                version: true,
+                url: `http://ghost.local`,
+                key: '5c73def7a21ad85eda5d4faa:d9a3e5b2d6c2a4afb094655c4dc543220be60b3561fa9622e3891213cb4357d0',
+                makeRequest: makeRequestStub,
+                generateToken: generateTokenSpy,
+                userAgent: false
+            });
+
+            await api.config.read();
+
+            makeRequestStub.calledOnce.should.be.true();
+            should.equal(makeRequestStub.args[0][0].headers['Accept-Version'], 'v5.0');
+            should.equal(makeRequestStub.args[0][0].headers['User-Agent'], undefined);
+            should.equal(generateTokenSpy.args[0][0], '5c73def7a21ad85eda5d4faa:d9a3e5b2d6c2a4afb094655c4dc543220be60b3561fa9622e3891213cb4357d0');
+            should.equal(generateTokenSpy.args[0][1], '/admin/');
+        });
     });
 });