chore(website): add copy button the code blocks

.eslintignore

@@ -10,4 +10,5 @@ website/build
 website/node_modules
 website/i18n/*.js
 website/translated_docs
+website/static
 !.eslintrc.js

package.json

@@ -95,8 +95,8 @@
     "jest-coverage": "yarn jest --coverage",
     "lint": "eslint . --cache --ext js,jsx,ts,tsx,md",
     "lint-es5-build": "eslint --no-eslintrc --no-ignore --env=browser packages/*/build-es5",
-    "lint:prettier": "prettier '**/*.{md,yml,yaml}' --write --ignore-path .gitignore",
-    "lint:prettier:ci": "prettier '**/*.{md,yml,yaml}' --check --ignore-path .gitignore",
+    "lint:prettier": "prettier '**/*.{md,yml,yaml}' 'website/static/**/*.{css,js}' --write --ignore-path .gitignore",
+    "lint:prettier:ci": "prettier '**/*.{md,yml,yaml}' 'website/static/**/*.{css,js}' --check --ignore-path .gitignore",
     "postinstall": "opencollective postinstall && yarn build",
     "install-no-ts-build": "node ./scripts/remove-postinstall && yarn --no-progress --frozen-lockfile && node ./scripts/build",
     "remove-prettier-dep": "node ./scripts/remove-prettier-dep",

scripts/checkCopyrightHeaders.js

@@ -102,6 +102,8 @@ const CUSTOM_IGNORED_PATTERNS = [
   '^packages/expect/src/jasmineUtils\\.ts$',
   '^packages/jest-config/src/vendor/jsonlint\\.js$',
   '^packages/jest-diff/src/cleanupSemantic\\.ts$',
+  '^website/static/css/code-block-buttons\\.css$',
+  '^website/static/js/code-block-buttons\\.js',
 ].map(createRegExp);
 
 const IGNORED_PATTERNS = [

website/siteConfig.js

@@ -121,7 +121,12 @@ const siteConfig = {
     secondaryColor: '#095708',
     prismColor: 'rgba(153, 66, 79, 0.03)',
   },
-  scripts: ['https://buttons.github.io/buttons.js'],
+  scripts: [
+    'https://buttons.github.io/buttons.js',
+    'https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.0/clipboard.min.js',
+    '/js/code-block-buttons.js',
+  ],
+  stylesheets: ['/css/code-block-buttons.css'],
   repoUrl,
   siteConfigUrl:
     'https://github.com/facebook/jest/edit/master/website/siteConfig.js',

website/static/css/code-block-buttons.css

@@ -0,0 +1,39 @@
+/* "Copy" code block button */
+pre {
+  position: relative;
+}
+
+pre .btnIcon {
+  position: absolute;
+  top: 4px;
+  z-index: 2;
+  cursor: pointer;
+  border: 1px solid transparent;
+  padding: 0;
+  color: var(--green);
+  background-color: transparent;
+  height: 30px;
+  transition: all 0.25s ease-out;
+}
+
+pre .btnIcon:hover {
+  text-decoration: none;
+}
+
+.btnIcon__body {
+  align-items: center;
+  display: flex;
+}
+
+.btnIcon svg {
+  fill: currentColor;
+  margin-right: 0.4em;
+}
+
+.btnIcon__label {
+  font-size: 11px;
+}
+
+.btnClipboard {
+  right: 10px;
+}

website/static/js/code-block-buttons.js

@@ -0,0 +1,45 @@
+window.addEventListener('load', function () {
+  function button(label, ariaLabel, icon, className) {
+    const btn = document.createElement('button');
+    btn.classList.add('btnIcon', className);
+    btn.setAttribute('type', 'button');
+    btn.setAttribute('aria-label', ariaLabel);
+    btn.innerHTML =
+      '<div class="btnIcon__body">' +
+      icon +
+      '<strong class="btnIcon__label">' +
+      label +
+      '</strong>' +
+      '</div>';
+    return btn;
+  }
+
+  function addButtons(codeBlockSelector, btn) {
+    document.querySelectorAll(codeBlockSelector).forEach(function (code) {
+      code.parentNode.appendChild(btn.cloneNode(true));
+    });
+  }
+
+  const copyIcon =
+    '<svg width="12" height="12" viewBox="340 364 14 15" xmlns="http://www.w3.org/2000/svg"><path fill="currentColor" d="M342 375.974h4v.998h-4v-.998zm5-5.987h-5v.998h5v-.998zm2 2.994v-1.995l-3 2.993 3 2.994v-1.996h5v-1.995h-5zm-4.5-.997H342v.998h2.5v-.997zm-2.5 2.993h2.5v-.998H342v.998zm9 .998h1v1.996c-.016.28-.11.514-.297.702-.187.187-.422.28-.703.296h-10c-.547 0-1-.452-1-.998v-10.976c0-.546.453-.998 1-.998h3c0-1.107.89-1.996 2-1.996 1.11 0 2 .89 2 1.996h3c.547 0 1 .452 1 .998v4.99h-1v-2.995h-10v8.98h10v-1.996zm-9-7.983h8c0-.544-.453-.996-1-.996h-1c-.547 0-1-.453-1-.998 0-.546-.453-.998-1-.998-.547 0-1 .452-1 .998 0 .545-.453.998-1 .998h-1c-.547 0-1 .452-1 .997z" fill-rule="evenodd"/></svg>';
+
+  addButtons(
+    '.hljs',
+    button('Copy', 'Copy code to clipboard', copyIcon, 'btnClipboard')
+  );
+
+  const clipboard = new ClipboardJS('.btnClipboard', {
+    target: function (trigger) {
+      return trigger.parentNode.querySelector('code');
+    },
+  });
+
+  clipboard.on('success', function (event) {
+    event.clearSelection();
+    const textEl = event.trigger.querySelector('.btnIcon__label');
+    textEl.textContent = 'Copied';
+    setTimeout(function () {
+      textEl.textContent = 'Copy';
+    }, 2000);
+  });
+});