Heatmap

package.json

@@ -7,9 +7,11 @@
     "@testing-library/react": "^10.4.5",
     "@testing-library/react-hooks": "^3.4.2",
     "@testing-library/user-event": "^12.0.11",
-    "eslint-plugin-styled-components-a11y": "^0.0.16",
+    "eslint-plugin-styled-components-a11y": "^0.0.17",
     "history": "^5.0.0",
+    "jest-axe": "^4.0.0",
     "jest-fetch-mock": "^3.0.3",
+    "jest-styled-components": "^7.0.3",
     "msw": "^0.21.2",
     "prop-types": "^15.7.2",
     "react": "^16.13.0",
@@ -23,7 +25,7 @@
   "scripts": {
     "start": "react-scripts start",
     "build": "react-scripts build",
-    "test": "react-scripts test --env=jest-environment-jsdom-sixteen",
+    "test": "TZ=Europe/Berlin react-scripts test --env=jest-environment-jsdom-sixteen",
     "eject": "react-scripts eject",
     "lint": "eslint .",
     "format": "eslint --fix .",

src/__tests__/SearchPage.js

@@ -1,16 +1,20 @@
 import React from 'react';
 import { MemoryRouter, Route } from 'react-router-dom';
-import { render, screen, within } from '@testing-library/react';
+import {
+  render, screen, within, waitFor,
+} from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import '@testing-library/jest-dom/extend-expect';
+import { axe } from 'jest-axe';
+import 'jest-styled-components';
 
 import App from '../app';
 import { defaultSubReddit } from '../config';
 
 const setup = (initialPath = '/') => {
   let history;
 
-  render(
+  const view = render(
     <MemoryRouter initialEntries={[initialPath]}>
       <App />
       <Route
@@ -22,19 +26,46 @@ const setup = (initialPath = '/') => {
       />
     </MemoryRouter>,
   );
-  return { history };
+  return { ...view, history };
 };
 
-describe('search page', () => {
+describe('heatmap', () => {
   it('loads top post for subreddit in URL', async () => {
     setup('/search/reactjs');
 
     screen.getByText('loading-spinner.svg');
 
     // this is just a placeholder assertion that tests if the result
     // was rendered correctly
-    expect(await screen.findByText('500')).toBeInTheDocument();
-    expect(screen.queryByText('loading-spinner.svg')).not.toBeInTheDocument();
+    // expect(await screen.findByText('500')).toBeInTheDocument();
+
+    expect(await screen.findByTestId('heatmap')).toBeInTheDocument();
+    await waitFor(() => expect(screen.queryByText('loading-spinner.svg')).not.toBeInTheDocument());
+
+    const heatmap = screen.getByTestId('heatmap');
+    const cells = await within(heatmap).findAllByRole('button');
+    expect(cells.length).toEqual(7 * 24);
+
+    const numberOfPostsPerCell = cells.map((cell) => cell.innerHTML);
+    expect(numberOfPostsPerCell).toMatchSnapshot();
+
+    const timezone = screen.getByText('All times are shown in your timezone:');
+    expect(within(timezone).getByText('Europe/Berlin')).toBeInTheDocument();
+  });
+
+  it('highlights cell on click', async () => {
+    setup('/search/reactjs');
+
+    const heatmap = await screen.findByTestId('heatmap');
+    const cells = await within(heatmap).findAllByRole('button');
+
+    const cellToClick = cells[1];
+    // expect(cellToClick).toHaveStyle('border: none');
+    expect(cellToClick).toHaveStyleRule('border: none');
+
+    userEvent.click(cellToClick);
+    // expect(cellToClick).toHaveStyle('border: 1px solid #1e2537');
+    expect(cellToClick).toHaveStyleRule('border: 1px solid #1e2537');
   });
 
   test('renders error message', async () => {
@@ -45,7 +76,7 @@ describe('search page', () => {
 });
 
 describe('subreddit form', () => {
-  it('updates the URL when submitting the form', () => {
+  it('updates the URL when submitting the form', async () => {
     const { history } = setup('/search/python');
     const searchInput = screen.getByLabelText('r /');
 
@@ -62,7 +93,7 @@ describe('subreddit form', () => {
     expect(history.location.pathname).toEqual('/search/Gatsbyjs');
   });
 
-  it('input value changes to default subredit when seach link in header is clicked', () => {
+  it('input value changes to default subredit when seach link in header is clicked', async () => {
     setup('/search/reactjs');
     const searchInput = screen.getByRole('textbox');
     const header = screen.getByRole('banner');
@@ -71,5 +102,13 @@ describe('subreddit form', () => {
     userEvent.click(searchLink);
 
     expect(searchInput.value).toBe(defaultSubReddit);
+    await waitFor(() => expect(screen.queryByText('loading-spinner.svg')).not.toBeInTheDocument());
+  });
+
+  it('no accessibility violation', async () => {
+    const { container } = setup('/search/reactjs');
+
+    expect(await screen.findByTestId('heatmap')).toBeInTheDocument();
+    expect(await axe(container)).toHaveNoViolations();
   });
 });

src/__tests__/_Heatmap.js_

@@ -0,0 +1,115 @@
+import React from 'react';
+import { MemoryRouter, Route } from 'react-router-dom';
+import {
+  render, screen, waitForElementToBeRemoved, within,
+} from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import '@testing-library/jest-dom/extend-expect';
+import 'jest-styled-components';
+
+import {
+  cellBackgroundColorMap, mapWeekday, postsTimeSlots, getUserTimeZone,
+} from '../config';
+
+import App from '../app';
+
+const weekdays = Object.values(mapWeekday);
+const cellBackgroundColor = Object.values(cellBackgroundColorMap);
+
+const setup = (initialPath = '/') => {
+  let history;
+
+  render(
+    <MemoryRouter initialEntries={[initialPath]}>
+      <App />
+      <Route
+        path="*"
+        render={(props) => {
+          history = props.history;
+          return null;
+        }}
+      />
+    </MemoryRouter>,
+  );
+  return { history };
+};
+
+describe('heatmap', () => {
+  it.each(weekdays)(
+    'weekdays are shown from Sunday to Saturday', async (weekday) => {
+      setup('/search/less-than-500-posts');
+      // find weekday container element tr.weekday
+      // assert that it contains Sunday, Monday, Tuesday, Wednesday
+      // Thursday, Friday, Saturday
+      const spinner = screen.getByText('loading-spinner.svg');
+
+      await waitForElementToBeRemoved(spinner);
+
+      screen.getByRole('table');
+      // weekday
+      screen.getByRole('cell', { name: weekday });
+    },
+  );
+
+  it.each(postsTimeSlots)(
+    'hours are shown from 12:00am to 10:00pm', async (postsTimeSlot) => {
+      setup('/search/reactjs');
+      // find hours container element th.timeline
+      // assert that it contains 12:00am, 2:00am..
+      const spinner = screen.getByText('loading-spinner.svg');
+
+      await waitForElementToBeRemoved(spinner);
+
+      screen.getByRole('table');
+
+      const timeSlots = screen.getAllByRole('columnheader');
+      // screen.debug(timeSlot);
+      within(timeSlots[1]).getByText(postsTimeSlot);
+    },
+  );
+
+  it('each combination of weekday and hour is represented by a square box', async () => {
+    setup('/search/less-than-500-posts');
+
+    const spinner = screen.getByText('loading-spinner.svg');
+    await waitForElementToBeRemoved(spinner);
+    screen.getByRole('table');
+
+    const cells = await document.querySelector('td.cell');
+    // select cells td.cell
+    const el = within(cells).getByText(cells.textContent);
+    const numPosts = Number(el.textContent);
+
+    expect(el).toHaveStyle({ border: 'unset', backgroundColor: '#a0ce93' });
+    // assert that background-color correspond to numeric innerText value
+    expect(el).toHaveStyle({ backgroundColor: `${cellBackgroundColor[numPosts]}` });
+
+    // assert that each has width === height
+    expect(el).toHaveStyleRule('width', '40px');
+    expect(el).toHaveStyleRule('height', '40px');
+
+    // assert that innerText.value is a number
+    // expect(el).toHaveValue(numPosts);
+
+    // assert that element is highlighted when hovered
+    userEvent.hover(el);
+    expect(el).toHaveStyle({ border: '1px solid red' });
+    userEvent.unhover(el);
+    expect(el).toHaveStyle({ border: 'unset' });
+
+    // assert that element is highlighted when clicked
+    userEvent.click(el);
+    expect(el).toHaveStyle({ border: '1px solid red' });
+  });
+
+  it("the user' timezone is shown below the heatmap", async () => {
+    setup('/search/less-than-500-posts');
+    // select div.timezone
+    // assert that the element contains "America/Chicago - Central Saving Time"
+    const spinner = screen.getByText('loading-spinner.svg');
+
+    await waitForElementToBeRemoved(spinner);
+    screen.getByRole('table');
+    screen.getByText(getUserTimeZone());
+  });
+});