Thomas Dillard - Frontend Challenge

frontend/.eslintrc.js

@@ -7,6 +7,8 @@ const ruleOverrides = {
   'canonical/export-specifier-newline': 0,
   'canonical/filename-match-regex': 0,
   'canonical/import-specifier-newline': 0,
+  // The `allowLineSeparatedGroups` option doesn't exist for canonical/sort-keys: https://github.com/gajus/eslint-plugin-canonical/issues/20
+  'canonical/sort-keys': 1,
   'default-case': 0,
   'default-case-last': 0,
   'import/extensions': 0,

frontend/.gitignore

@@ -0,0 +1,130 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+lerna-debug.log*
+.pnpm-debug.log*
+
+# Diagnostic reports (https://nodejs.org/api/report.html)
+report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
+
+# Runtime data
+pids
+*.pid
+*.seed
+*.pid.lock
+
+# Directory for instrumented libs generated by jscoverage/JSCover
+lib-cov
+
+# Coverage directory used by tools like istanbul
+coverage
+*.lcov
+
+# nyc test coverage
+.nyc_output
+
+# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
+.grunt
+
+# Bower dependency directory (https://bower.io/)
+bower_components
+
+# node-waf configuration
+.lock-wscript
+
+# Compiled binary addons (https://nodejs.org/api/addons.html)
+build/Release
+
+# Dependency directories
+node_modules/
+jspm_packages/
+
+# Snowpack dependency directory (https://snowpack.dev/)
+web_modules/
+
+# TypeScript cache
+*.tsbuildinfo
+
+# Optional npm cache directory
+.npm
+
+# Optional eslint cache
+.eslintcache
+
+# Optional stylelint cache
+.stylelintcache
+
+# Microbundle cache
+.rpt2_cache/
+.rts2_cache_cjs/
+.rts2_cache_es/
+.rts2_cache_umd/
+
+# Optional REPL history
+.node_repl_history
+
+# Output of 'npm pack'
+*.tgz
+
+# Yarn Integrity file
+.yarn-integrity
+
+# dotenv environment variable files
+.env
+.env.development.local
+.env.test.local
+.env.production.local
+.env.local
+
+# parcel-bundler cache (https://parceljs.org/)
+.cache
+.parcel-cache
+
+# Next.js build output
+.next
+out
+
+# Nuxt.js build / generate output
+.nuxt
+dist
+
+# Gatsby files
+.cache/
+# Comment in the public line in if your project uses Gatsby and not Next.js
+# https://nextjs.org/blog/next-9-1#public-directory-support
+# public
+
+# vuepress build output
+.vuepress/dist
+
+# vuepress v2.x temp and cache directory
+.temp
+.cache
+
+# Docusaurus cache and generated files
+.docusaurus
+
+# Serverless directories
+.serverless/
+
+# FuseBox cache
+.fusebox/
+
+# DynamoDB Local files
+.dynamodb/
+
+# TernJS port file
+.tern-port
+
+# Stores VSCode versions used for testing VSCode extensions
+.vscode-test
+
+# yarn v2
+.yarn/cache
+.yarn/unplugged
+.yarn/build-state.yml
+.yarn/install-state.gz
+.pnp.*

frontend/.yarnrc.yml

@@ -0,0 +1 @@
+nodeLinker: node-modules

frontend/jest.config.js

@@ -11,8 +11,11 @@ const customJestConfig = {
   // Add more setup options before each test is run
   // setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
   // if using TypeScript with a baseUrl set to the root directory then you need the below for alias' to work
-  moduleDirectories: ['node_modules', '<rootDir>/'],
+  moduleDirectories: ['node_modules', 'src'],
   testEnvironment: 'jest-environment-jsdom',
+  moduleNameMapper: {
+   "^@/(.*)": "<rootDir>/src/$1"
+  }
 };
 
 // createJestConfig is exported this way to ensure that next/jest can load the Next.js config which is async

frontend/package.json

@@ -9,15 +9,19 @@
     "lint": "yarn lint:eslint && yarn lint:prettier",
     "lint:eslint": "eslint './src/**/*.{js,ts,tsx}' --cache",
     "lint:prettier": "prettier --ignore-path .gitignore --check './**/*.{js,ts,tsx}'",
-    "test": "NODE_ENV=test jest --watch",
+    "test": "NODE_ENV=test jest -c jest.config.js --watch",
     "test:ci": "NODE_ENV=test jest --ci --reporters jest-silent-reporter"
   },
   "dependencies": {
+    "@stitches/react": "^1.2.8",
+    "@testing-library/user-event": "^14.4.3",
     "next": "12.1.6",
     "react": "18.2.0",
     "react-dom": "18.2.0"
   },
   "devDependencies": {
+    "@testing-library/jest-dom": "^5.16.5",
+    "@testing-library/react": "^14.0.0",
     "@types/jest": "28.1.3",
     "@types/node": "18.0.0",
     "@types/react": "18.0.14",
@@ -26,7 +30,8 @@
     "eslint-config-canonical": "35.0.1",
     "eslint-config-next": "12.1.6",
     "eslint-config-prettier": "8.5.0",
-    "jest": "28.1.1",
+    "jest": "^29.5.0",
+    "jest-environment-jsdom": "^29.5.0",
     "lint-staged": "13.0.3",
     "prettier": "2.7.1",
     "typescript": "4.7.4"

frontend/src/__tests__/Modal.spec.tsx

@@ -0,0 +1,65 @@
+import { render, screen, waitFor } from '@testing-library/react';
+import userEvent from '@testing-library/user-event';
+import React from 'react';
+import { Modal } from '@/components/Modal';
+
+const renderModal = (open: boolean, onClose = () => {}) => {
+  return render(
+    <Modal data-testId="modal" onClose={onClose} open={open}>
+      <input data-testid="input1" />
+      <input data-testid="input2" />
+      <button data-testid="button" type="button">
+        Close
+      </button>
+    </Modal>
+  );
+};
+
+describe('Modal', () => {
+  it('focuses on the first element when opened', async () => {
+    renderModal(true);
+    const firstElement = screen.getByTestId('input1');
+    await waitFor(() => expect(document.activeElement).not.toBe(document));
+
+    expect(document.activeElement).toBe(firstElement);
+  });
+
+  it('focuses on the next element when tab is pressed', async () => {
+    renderModal(true);
+    const secondElement = screen.getByTestId('input2');
+
+    await userEvent.keyboard('{Tab}');
+
+    expect(document.activeElement).toBe(secondElement);
+  });
+
+  it('focuses on the first element when tab is pressed on the last element', async () => {
+    renderModal(true);
+    const firstElement = screen.getByTestId('input1');
+    const lastElement = screen.getByTestId('button');
+
+    lastElement.focus();
+    await userEvent.keyboard('{Tab}');
+
+    expect(document.activeElement).toBe(firstElement);
+  });
+
+  it('focuses on the last element when shift + tab is pressed on first element', async () => {
+    renderModal(true);
+    const firstElement = screen.getByTestId('input1');
+    const lastElement = screen.getByTestId('button');
+
+    firstElement.focus();
+    await userEvent.keyboard('{Shift>}{Tab}');
+
+    expect(document.activeElement).toBe(lastElement);
+  });
+
+  it('closes the modal when escape key is pressed', async () => {
+    const handleClose = jest.fn();
+    renderModal(true, handleClose);
+    await userEvent.keyboard('{Escape}');
+
+    expect(handleClose).toHaveBeenCalled();
+  });
+});

frontend/src/components/Modal.tsx

@@ -0,0 +1,67 @@
+import { type PropsWithChildren, type HTMLAttributes } from 'react';
+import { styled } from '@/utils/styles';
+import { useEscapeKeyListener } from '@/utils/use-escape-trap';
+import { useFocusTrap } from '@/utils/use-focus-trap';
+import { useScrollLock } from '@/utils/use-scroll-lock';
+import { ReactPortal } from './ReactPortal';
+
+const ModalBackground = styled('div', {
+  backgroundColor: 'rgba(0,0,0,0.7)',
+  bottom: 0,
+  left: 0,
+  position: 'fixed',
+  right: 0,
+  top: 0,
+  zIndex: 10,
+});
+
+const ModalContainer = styled('div', {
+  backgroundColor: '#fefefe',
+  border: '1px solid #888',
+  boxShadow: '0 4px 8px 0 rgba(0, 0, 0, 0.2), 0 6px 20px 0 rgba(0, 0, 0, 0.19)',
+  display: 'flex',
+  flexDirection: 'column',
+  height: '100%',
+  margin: 0,
+  padding: '20px',
+  width: '100%',
+
+  // eslint-disable-next-line canonical/sort-keys
+  '@md': {
+    borderRadius: '4px',
+    height: 'auto',
+    margin: '10% auto',
+    width: '50%',
+  },
+});
+
+type ModalProps = HTMLAttributes<HTMLDivElement> &
+  PropsWithChildren<{
+    onClose: () => void;
+    open: boolean;
+  }>;
+
+// event.relatedTarget might be worth researching in the future
+export const Modal = ({ children, open, onClose, ...props }: ModalProps) => {
+  const ref = useFocusTrap<HTMLDivElement>();
+  useScrollLock(open);
+  useEscapeKeyListener(onClose);
+
+  if (!open) return null;
+
+  return (
+    <ReactPortal>
+      <ModalBackground>
+        <ModalContainer
+          aria-hidden={!open}
+          aria-modal
+          ref={ref}
+          role="dialog"
+          {...props}
+        >
+          {children}
+        </ModalContainer>
+      </ModalBackground>
+    </ReactPortal>
+  );
+};

frontend/src/components/ReactPortal.ts

@@ -0,0 +1,37 @@
+import { type PropsWithChildren, useState } from 'react';
+import { createPortal } from 'react-dom';
+import { useIsomorphicLayoutEffect } from '@/utils/use-isomorphic-layout';
+
+type WrapperId = string;
+
+const createRootElement = (wrapperId: WrapperId) => {
+  const wrapperElement = document.createElement('div');
+  wrapperElement.setAttribute('id', wrapperId);
+  document.body.appendChild(wrapperElement);
+  return wrapperElement;
+};
+
+export const ReactPortal = ({
+  children,
+  wrapperId = 'contra-frontend-modal',
+}: PropsWithChildren<{ wrapperId?: WrapperId }>) => {
+  const [domNode, setDomNode] = useState<HTMLDivElement | null>(null);
+
+  useIsomorphicLayoutEffect(() => {
+    let element = document.querySelector<HTMLDivElement>(wrapperId);
+    if (!element) {
+      element = createRootElement(wrapperId);
+    }
+
+    setDomNode(element);
+
+    return () => {
+      if (element?.parentNode) {
+        element.parentNode.removeChild(element);
+      }
+    };
+  }, [wrapperId]);
+
+  if (domNode === null) return null;
+  return createPortal(children, domNode);
+};