chore: add e2e tests using Cypress

Author: bahmutov

.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 .DS_Store
 npm-debug.log
+cypress/videos

cypress.json

@@ -0,0 +1,4 @@
+{
+  "baseUrl": "http://localhost:3000",
+  "videoRecording": false
+}

cypress/fixtures/data.json

@@ -0,0 +1,3 @@
+{
+  "todos": []
+}

cypress/fixtures/example.json

@@ -0,0 +1,5 @@
+{
+  "name": "Using fixtures to represent data",
+  "email": "hello@cypress.io",
+  "body": "Fixtures are a great way to mock data for responses to routes"
+}

cypress/integration/spec.js

@@ -0,0 +1,41 @@
+/* eslint-env mocha */
+/* global cy */
+describe('json-server-reset', () => {
+  const reset = () => {
+    cy.request({
+      method: 'POST',
+      url: '/reset',
+      body: {
+        todos: []
+      }
+    })
+  }
+  beforeEach(reset)
+
+  const getTodos = () => cy.request('/todos').its('body')
+
+  const addTodo = () =>
+    cy.request({
+      method: 'POST',
+      url: '/todos',
+      body: {
+        id: 1,
+        title: 'do something'
+      }
+    })
+
+  it('starts with empty list of todos', () => {
+    getTodos().should('deep.equal', [])
+  })
+
+  it('can add a todo', () => {
+    addTodo()
+    getTodos().should('deep.equal', [{ id: 1, title: 'do something' }])
+  })
+
+  it('can reset todos', () => {
+    addTodo()
+    reset()
+    getTodos().should('deep.equal', [])
+  })
+})

cypress/plugins/index.js

@@ -0,0 +1,17 @@
+// ***********************************************************
+// This example plugins/index.js can be used to load plugins
+//
+// You can change the location of this file or turn off loading
+// the plugins file with the 'pluginsFile' configuration option.
+//
+// You can read more here:
+// https://on.cypress.io/plugins-guide
+// ***********************************************************
+
+// This function is called when a project is opened or re-opened (e.g. due to
+// the project's config changing)
+
+module.exports = (on, config) => {
+  // `on` is used to hook into various events Cypress emits
+  // `config` is the resolved Cypress config
+}

cypress/support/commands.js

@@ -0,0 +1,25 @@
+// ***********************************************
+// This example commands.js shows you how to
+// create various custom commands and overwrite
+// existing commands.
+//
+// For more comprehensive examples of custom
+// commands please read more here:
+// https://on.cypress.io/custom-commands
+// ***********************************************
+//
+//
+// -- This is a parent command --
+// Cypress.Commands.add("login", (email, password) => { ... })
+//
+//
+// -- This is a child command --
+// Cypress.Commands.add("drag", { prevSubject: 'element'}, (subject, options) => { ... })
+//
+//
+// -- This is a dual command --
+// Cypress.Commands.add("dismiss", { prevSubject: 'optional'}, (subject, options) => { ... })
+//
+//
+// -- This is will overwrite an existing command --
+// Cypress.Commands.overwrite("visit", (originalFn, url, options) => { ... })

cypress/support/index.js

@@ -0,0 +1,20 @@
+// ***********************************************************
+// This example support/index.js is processed and
+// loaded automatically before your test files.
+//
+// This is a great place to put global configuration and
+// behavior that modifies Cypress.
+//
+// You can change the location of this file or turn off
+// automatically serving support files with the
+// 'supportFile' configuration option.
+//
+// You can read more here:
+// https://on.cypress.io/configuration
+// ***********************************************************
+
+// Import commands.js using ES2015 syntax:
+import './commands'
+
+// Alternatively you can use CommonJS syntax:
+// require('./commands')

package.json

@@ -61,7 +61,11 @@
     "size": "t=\"$(npm pack .)\"; wc -c \"${t}\"; tar tvf \"${t}\"; rm \"${t}\";",
     "test": "npm run unit",
     "unit": "mocha src/*-spec.js",
-    "unused-deps": "dependency-check --unused --no-dev ."
+    "unused-deps": "dependency-check --unused --no-dev .",
+    "cy:open": "cypress open",
+    "cy:run": "cypress run",
+    "start": "json-server cypress/fixtures/data.json --middlewares ./src/index.js",
+    "e2e": "start-server-and-test start http://localhost:3000 cy:run"
   },
   "release": {
     "analyzeCommits": "simple-commit-message"
@@ -73,12 +77,14 @@
     "dependency-check": "2.9.1",
     "deps-ok": "1.2.1",
     "git-issues": "1.3.1",
+    "json-server": "0.12.1",
     "lazy-ass": "1.6.0",
     "license-checker": "15.0.0",
     "mocha": "4.0.1",
     "nsp": "3.1.0",
     "pre-git": "3.16.0",
     "prettier-standard": "7.0.3",
-    "standard": "10.0.3"
+    "standard": "10.0.3",
+    "start-server-and-test": "1.0.0"
   }
 }