diff --git a/views/ngXosViews/diagnostic/spec/rackHelper.test.js b/views/ngXosViews/diagnostic/spec/rackHelper.test.js
new file mode 100644
index 0000000..932b17f
--- /dev/null
+++ b/views/ngXosViews/diagnostic/spec/rackHelper.test.js
@@ -0,0 +1,117 @@
+(function () {
+  'use strict';
+
+  const computeNodes = [
+    {
+      humanReadableName: 'cp-1.teone.xos-pg0.clemson.cloudlab.us',
+      instances: [
+        {
+          instance_name: 'mysite_clients-3'
+        },
+        {
+          instance_name: 'mysite_clients-4'
+        },
+        {
+          instance_name: 'mysite_clients-5'
+        }
+      ]
+    },
+    {
+      humanReadableName: 'cp-2.teone.xos-pg0.clemson.cloudlab.us',
+      instances: [
+        {
+          instance_name: 'mysite_clients-1'
+        },
+        {
+          instance_name: 'mysite_clients-2'
+        }
+      ]
+    },
+    {
+      humanReadableName: 'cp-2.teone.xos-pg0.clemson.cloudlab.us',
+      instances: [
+        {
+          instance_name: 'mysite_clients-1'
+        },
+        {
+          instance_name: 'mysite_clients-2'
+        }
+      ]
+    }
+  ];
+
+  describe('The Rack Helper Service', () => {
+    
+    var Service;
+
+    beforeEach(module('xos.serviceTopology'));
+
+    // inject the rackHelper service
+    beforeEach(inject(function (_RackHelper_) {
+      // The injector unwraps the underscores (_) from around the parameter names when matching
+      Service = _RackHelper_;
+    }));
+
+    describe('Given a list of instances', () => {
+      it('should calculate the Compute Node Size', () => {
+        const [width, height] = Service.getComputeNodeSize(computeNodes[0].instances);
+        expect(width).toBe(95);
+        expect(height).toBe(67);
+      });
+    });
+
+    describe('Given a list of Compute Nodes', () => {
+      it('should return rack size', () => {
+        const [width, height] = Service.getRackSize(computeNodes);
+        expect(width).toBe(105);
+        expect(height).toBe(179);
+      });
+    });
+
+    describe('Given an instance index', () => {
+      it('should return the position for first instance', () => {
+        const [x, y] = Service.getInstancePosition(0);
+        expect(x).toBe(5);
+        expect(y).toBe(25);
+      });
+
+      it('should return the position for second instance', () => {
+        const [x, y] = Service.getInstancePosition(1);
+        expect(x).toBe(50);
+        expect(y).toBe(25);
+      });
+
+      it('should return the position for third instance', () => {
+        const [x, y] = Service.getInstancePosition(2);
+        expect(x).toBe(5);
+        expect(y).toBe(46);
+      });
+
+      it('should return the position for 4th instance', () => {
+        const [x, y] = Service.getInstancePosition(3);
+        expect(x).toBe(50);
+        expect(y).toBe(46);
+      });
+    });
+
+    describe('Given an ComputeNode index', () => {
+      it('should return the position for 1st node', () => {
+        const [x, y] = Service.getComputeNodePosition(computeNodes, 0);
+        expect(x).toBe(5);
+        expect(y).toBe(5);
+      });
+
+      it('should return the position for 2st node', () => {
+        const [x, y] = Service.getComputeNodePosition(computeNodes, 1);
+        expect(x).toBe(5);
+        expect(y).toBe(77);
+      });
+
+      it('should return the position for 2st node', () => {
+        const [x, y] = Service.getComputeNodePosition(computeNodes, 2);
+        expect(x).toBe(5);
+        expect(y).toBe(128);
+      });
+    });
+  });
+})();