467/add cypress testing

.eslintignore

@@ -1,2 +1,4 @@
 node_modules/
 !.storybook/
+cypress/e2e/1-getting-started/
+cypress/e2e/2-advanced-examples/

.eslintrc.json

@@ -1,16 +1,22 @@
 {
-  "extends": ["react-app", "plugin:prettier/recommended"],
+  "extends": [
+    "react-app",
+    "plugin:prettier/recommended",
+    "plugin:cypress/recommended"
+  ],
   "rules": {
     "no-unused-vars": ["error", { "varsIgnorePattern": "^_" }]
   },
   "overrides": [
     {
-      "files": [
-        "**/*.stories.*"
-      ],
+      "files": ["**/*.stories.*"],
       "rules": {
         "import/no-anonymous-default-export": "off"
       }
     }
-  ]
+  ],
+  "globals": {
+    "cy": true
+  },
+  "plugins": ["cypress"]
 }

.gitignore

@@ -21,3 +21,9 @@
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+
+# cypress testing
+/cypress/videos
+/cypress/screenshots
+/cypress/reports
+/cypress/fixtures

cypress.config.js

@@ -0,0 +1,26 @@
+const { defineConfig } = require("cypress");
+// const customViteConfig = require("./vite.config");
+
+module.exports = defineConfig({
+  e2e: {
+    // eslint-disable-next-line no-unused-vars
+    setupNodeEvents(on, config) {
+      // implement node event listeners here
+    },
+  },
+  component: {
+    devServer: {
+      framework: "react",
+      bundler: "vite",
+      // optionally pass in vite config
+      // viteConfig: customViteConfig,
+      // or a function - the result is merged with
+      // any `vite.config` file that is detected
+      // viteConfig: async () => {
+      //   // ... do things ...
+      //   const modifiedConfig = await injectCustomConfig(baseConfig);
+      //   return modifiedConfig;
+      // },
+    },
+  },
+});

cypress/e2e/1-getting-started/todo.cy.js

@@ -0,0 +1,144 @@
+/* eslint-disable prettier/prettier */
+/// <reference types="cypress" />
+
+// Welcome to Cypress!
+//
+// This spec file contains a variety of sample tests
+// for a todo list app that are designed to demonstrate
+// the power of writing tests in Cypress.
+//
+// To learn more about how Cypress works and
+// what makes it such an awesome testing tool,
+// please read our getting started guide:
+// https://on.cypress.io/introduction-to-cypress
+
+describe("example to-do app", () => {
+  beforeEach(() => {
+    // Cypress starts out with a blank slate for each test
+    // so we must tell it to visit our website with the `cy.visit()` command.
+    // Since we want to visit the same URL at the start of all our tests,
+    // we include it in our beforeEach function so that it runs before each test
+    cy.visit("https://example.cypress.io/todo");
+  });
+
+  it("displays two todo items by default", () => {
+    // We use the `cy.get()` command to get all elements that match the selector.
+    // Then, we use `should` to assert that there are two matched items,
+    // which are the two default items.
+    cy.get(".todo-list li").should("have.length", 2);
+
+    // We can go even further and check that the default todos each contain
+    // the correct text. We use the `first` and `last` functions
+    // to get just the first and last matched elements individually,
+    // and then perform an assertion with `should`.
+    cy.get(".todo-list li").first().should("have.text", "Pay electric bill");
+    cy.get(".todo-list li").last().should("have.text", "Walk the dog");
+  });
+
+  it("can add new todo items", () => {
+    // We'll store our item text in a variable so we can reuse it
+    const newItem = "Feed the cat";
+
+    // Let's get the input element and use the `type` command to
+    // input our new list item. After typing the content of our item,
+    // we need to type the enter key as well in order to submit the input.
+    // This input has a data-test attribute so we'll use that to select the
+    // element in accordance with best practices:
+    // https://on.cypress.io/selecting-elements
+    cy.get("[data-test=new-todo]").type(`${newItem}{enter}`);
+
+    // Now that we've typed our new item, let's check that it actually was added to the list.
+    // Since it's the newest item, it should exist as the last element in the list.
+    // In addition, with the two default items, we should have a total of 3 elements in the list.
+    // Since assertions yield the element that was asserted on,
+    // we can chain both of these assertions together into a single statement.
+    cy.get(".todo-list li")
+      .should("have.length", 3)
+      .last()
+      .should("have.text", newItem);
+  });
+
+  it("can check off an item as completed", () => {
+    // In addition to using the `get` command to get an element by selector,
+    // we can also use the `contains` command to get an element by its contents.
+    // However, this will yield the <label>, which is lowest-level element that contains the text.
+    // In order to check the item, we'll find the <input> element for this <label>
+    // by traversing up the dom to the parent element. From there, we can `find`
+    // the child checkbox <input> element and use the `check` command to check it.
+    cy.contains("Pay electric bill")
+      .parent()
+      .find("input[type=checkbox]")
+      .check();
+
+    // Now that we've checked the button, we can go ahead and make sure
+    // that the list element is now marked as completed.
+    // Again we'll use `contains` to find the <label> element and then use the `parents` command
+    // to traverse multiple levels up the dom until we find the corresponding <li> element.
+    // Once we get that element, we can assert that it has the completed class.
+    cy.contains("Pay electric bill")
+      .parents("li")
+      .should("have.class", "completed");
+  });
+
+  context("with a checked task", () => {
+    beforeEach(() => {
+      // We'll take the command we used above to check off an element
+      // Since we want to perform multiple tests that start with checking
+      // one element, we put it in the beforeEach hook
+      // so that it runs at the start of every test.
+      cy.contains("Pay electric bill")
+        .parent()
+        .find("input[type=checkbox]")
+        .check();
+    });
+
+    it("can filter for uncompleted tasks", () => {
+      // We'll click on the "active" button in order to
+      // display only incomplete items
+      cy.contains("Active").click();
+
+      // After filtering, we can assert that there is only the one
+      // incomplete item in the list.
+      cy.get(".todo-list li")
+        .should("have.length", 1)
+        .first()
+        .should("have.text", "Walk the dog");
+
+      // For good measure, let's also assert that the task we checked off
+      // does not exist on the page.
+      cy.contains("Pay electric bill").should("not.exist");
+    });
+
+    it("can filter for completed tasks", () => {
+      // We can perform similar steps as the test above to ensure
+      // that only completed tasks are shown
+      cy.contains("Completed").click();
+
+      cy.get(".todo-list li")
+        .should("have.length", 1)
+        .first()
+        .should("have.text", "Pay electric bill");
+
+      cy.contains("Walk the dog").should("not.exist");
+    });
+
+    it("can delete all completed tasks", () => {
+      // First, let's click the "Clear completed" button
+      // `contains` is actually serving two purposes here.
+      // First, it's ensuring that the button exists within the dom.
+      // This button only appears when at least one task is checked
+      // so this command is implicitly verifying that it does exist.
+      // Second, it selects the button so we can click it.
+      cy.contains("Clear completed").click();
+
+      // Then we can make sure that there is only one element
+      // in the list and our element does not exist
+      cy.get(".todo-list li")
+        .should("have.length", 1)
+        .should("not.have.text", "Pay electric bill");
+
+      // Finally, make sure that the clear button no longer exists.
+      cy.contains("Clear completed").should("not.exist");
+    });
+  });
+});