test: add Service test

priv/frontend/src/components/__tests__/Service.js

@@ -0,0 +1,49 @@
+import React from 'react'
+import { shallow } from 'enzyme'
+
+import Service, { getServiceState } from '../Service'
+
+const graph = [
+  [1000, 50],
+  [2000, 30],
+  [3000, 60],
+]
+
+const props = {
+  name: 'sample service',
+  description: 'a cool service',
+  latency: 50.5,
+}
+
+describe('<Service/>', () => {
+  it('renders without crashing', () => {
+    shallow(<Service graph={null} status {...props}/>)
+  })
+
+  it('omits information', () => {
+    const comp = shallow(<Service graph={null} status {...props} latency={null}/>)
+    expect(comp.find('h2.title').text()).toEqual('sample service ')
+  })
+
+  it('renders proper information', () => {
+    const comp = shallow(<Service graph={graph} status {...props}/>)
+    expect(comp.prop('className')).toEqual('service service-alive')
+    expect(comp.find('h2.title').text()).toEqual('sample service 51ms')
+    expect(comp.contains(<p className="description">a cool service</p>)).toEqual(true)
+    expect(comp.contains(<span className="latency">51ms</span>)).toEqual(true)
+  })
+})
+
+describe('getServiceState', () => {
+  it('returns alive', () => {
+    expect(getServiceState(true, 10, 5000)).toEqual('alive')
+  })
+
+  it('returns slow', () => {
+    expect(getServiceState(true, 8000, 5000)).toEqual('slow')
+  })
+
+  it('returns dead', () => {
+    expect(getServiceState(false, 0, 5000)).toEqual('dead')
+  })
+})