diff --git a/__tests__/spec/data-storage.js b/__tests__/spec/data-storage.js
new file mode 100644
index 0000000000..e140e385f2
--- /dev/null
+++ b/__tests__/spec/data-storage.js
@@ -0,0 +1,76 @@
+/* eslint-env jest */
+const request = require('supertest')
+const app = require('../../server.js')
+const path = require('path')
+const fs = require('fs')
+const utils = require('../../lib/utils.js')
+
+jest.setTimeout(30000)
+
+function readFile (pathFromRoot) {
+  return fs.readFileSync(path.join(__dirname, '../../' + pathFromRoot), 'utf8')
+}
+/**
+ *
+ */
+describe('The data storage', () => {
+  // check session-data defaults file exists
+
+  it.skip('file should exist', (done) => {
+    const sessionDataDefaultsFile = readFile('app/data/session-data-defaults.js')
+
+    request(app)
+      .get(sessionDataDefaultsFile)
+      .expect('Content-Type', /application\/javascript; charset=UTF-8/)
+      // .expect(200)
+      .end(function (err, res) {
+        if (err) {
+          done(err)
+        } else {
+          done()
+        }
+      })
+  })
+
+  describe('storeData function', () => {
+    it('should add input data into session data', async () => {
+      let initialSessionData = {
+        'driver-name': 'Dr Emmett Brown'
+      }
+
+      const inputData = {
+        'vehicle-registration': 'OUTATIME'
+      }
+
+      utils.storeData(inputData, initialSessionData)
+
+      expect(initialSessionData).toEqual({
+        'driver-name': 'Dr Emmett Brown',
+        'vehicle-registration': 'OUTATIME'
+      })
+    })
+
+    it('should merge object into object', async () => {
+      let initialSessionData = {
+        vehicle: {
+          'driver-name': 'Dr Emmett Brown'
+        }
+      }
+
+      const inputData = {
+        vehicle: {
+          registration: 'OUTATIME'
+        }
+      }
+
+      utils.storeData(inputData, initialSessionData)
+
+      expect(initialSessionData).toEqual({
+        vehicle: {
+          'driver-name': 'Dr Emmett Brown',
+          registration: 'OUTATIME'
+        }
+      })
+    })
+  })
+})
diff --git a/lib/utils.js b/lib/utils.js
index 068fddf2c4..ac76bd25a0 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -220,7 +220,7 @@ exports.matchMdRoutes = function (req, res) {
 }
 
 // Store data from POST body or GET query in session
-var storeData = function (input, data) {
+function storeData (input, data) {
   // Value we store to indicate unchecked checkboxes. See `auto-store-data.js`
   var uncheckedValue = '_unchecked'
 
@@ -257,6 +257,8 @@ var storeData = function (input, data) {
   }
 }
 
+exports.storeData = storeData
+
 // Get session default data from file
 let sessionDataDefaults = {}