feat: Adding implementation of startWithEncryptionKey api call

src/vm.js

@@ -985,6 +985,58 @@ class VM extends common.ServiceObject {
       callback || common.util.noop
     );
   }
+  /**
+   * Start an instance with customer encrypted disks.
+   *
+   * @see [Instances: start API Documentation]{@link https://cloud.google.com/compute/docs/reference/rest/v1/instances/startWithEncryptionKey}
+   *
+   * @param {object[]} disks - An array of the encrypted disks and their keys.
+   * @param {function=} callback - The callback function.
+   * @param {?error} callback.err - An error returned while making this request.
+   * @param {Operation} callback.operation - An operation object
+   *     that can be used to check the status of the request.
+   * @param {object} callback.apiResponse - The full API response.
+   *
+   * @example
+   * const Compute = require('@google-cloud/compute');
+   * const compute = new Compute();
+   * const zone = compute.zone('zone-name');
+   * const vm = zone.vm('vm-name');
+   *
+   * var disks = [
+   *  {
+   *    source: 'disk_name',
+   *    diskEncryptionKey: {
+   *      rawKey: '...'
+   *    }
+   *  }
+   * ]
+   *
+   * vm.startWithEncryptionKey(disks, function(err, operation, apiResponse) {
+   *   // `operation` is an Operation object that can be used to check the status
+   *   // of the request.
+   * });
+   *
+   * //-
+   * // If the callback is omitted, we'll return a Promise.
+   * //-
+   * vm.startWithEncryptionKey(disks).then(function(data) {
+   *   const operation = data[0];
+   *   const apiResponse = data[1];
+   * });
+   */
+  startWithEncryptionKey(disks, callback) {
+    this.request(
+      {
+        method: 'POST',
+        uri: '/startWithEncryptionKey',
+        json: {
+          disks,
+        },
+      },
+      callback || common.util.noop
+    );
+  }
   /**
    * Stop the instance.
    *

test/vm.js

@@ -941,6 +941,33 @@ describe('VM', () => {
     });
   });
 
+  describe('startWithEncryptionKey', () => {
+    const DISKS = [];
+
+    it('should make the correct API request', done => {
+      vm.request = function (reqOpts, callback) {
+        assert.strictEqual(reqOpts.method, 'POST');
+        assert.strictEqual(reqOpts.uri, '/startWithEncryptionKey');
+        assert.strictEqual(reqOpts.json.disks, DISKS);
+
+        callback();
+      };
+
+      vm.startWithEncryptionKey(DISKS, done);
+    });
+
+    it('should not require a callback', done => {
+      vm.request = function (reqOpts, callback) {
+        assert.doesNotThrow(() => {
+          callback();
+          done();
+        });
+      };
+
+      vm.start();
+    });
+  });
+
   describe('stop', () => {
     it('should make the correct API request', done => {
       vm.request = function (reqOpts, callback) {