From 5ca5e232dd8854decf66bca70c42ddea5b8475d3 Mon Sep 17 00:00:00 2001
From: rayangler <27821750+rayangler@users.noreply.github.com>
Date: Tue, 17 Sep 2024 14:55:29 -0400
Subject: [PATCH] DOP-4941: Allow fonts for hidden languages to work without
 feature flag (#1239)

---
 gatsby-ssr.js                                 |  7 +-
 src/components/DocumentBody.js                | 14 +--
 src/components/Footer.js                      |  4 +-
 src/components/Header/index.js                |  4 +-
 src/components/Sidenav/Sidenav.js             | 14 +--
 src/constants.js                              |  4 +
 src/layouts/index.js                          |  3 +
 .../head-scripts/redirect-based-on-lang.js    |  1 +
 src/utils/locale.js                           | 85 ++++++++++++++-----
 tests/unit/Head.test.js                       |  4 +-
 tests/unit/utils/locale.test.js               | 15 +++-
 11 files changed, 100 insertions(+), 55 deletions(-)

diff --git a/gatsby-ssr.js b/gatsby-ssr.js
index c9533d8a3..0ff7d91a4 100644
--- a/gatsby-ssr.js
+++ b/gatsby-ssr.js
@@ -5,8 +5,9 @@ import { renderToString } from 'react-dom/server';
 import { theme } from './src/theme/docsTheme';
 import EuclidCircularASemiBold from './src/styles/fonts/EuclidCircularA-Semibold-WebXL.woff';
 import redirectBasedOnLang from './src/utils/head-scripts/redirect-based-on-lang';
+import { getHtmlLangFormat } from './src/utils/locale';
 
-export const onRenderBody = ({ setHeadComponents }) => {
+export const onRenderBody = ({ setHeadComponents, setHtmlAttributes }) => {
   const headComponents = [
     // GTM Pathway
     <script
@@ -84,6 +85,10 @@ export const onRenderBody = ({ setHeadComponents }) => {
       />
     );
   }
+  setHtmlAttributes({
+    // Help work with translated content locally; Smartling should handle rewriting the lang
+    lang: process.env.GATSBY_LOCALE ? getHtmlLangFormat(process.env.GATSBY_LOCALE) : 'en',
+  });
   setHeadComponents(headComponents);
 };
 
diff --git a/src/components/DocumentBody.js b/src/components/DocumentBody.js
index b50009310..5eaa18311 100644
--- a/src/components/DocumentBody.js
+++ b/src/components/DocumentBody.js
@@ -1,7 +1,6 @@
 import React, { useState, lazy } from 'react';
 import PropTypes from 'prop-types';
 import { graphql } from 'gatsby';
-import { Global, css } from '@emotion/react';
 import { ImageContextProvider } from '../context/image-context';
 import { usePresentationMode } from '../hooks/use-presentation-mode';
 import { useCanonicalUrl } from '../hooks/use-canonical-url';
@@ -11,11 +10,11 @@ import { getMetaFromDirective } from '../utils/get-meta-from-directive';
 import { getPlaintext } from '../utils/get-plaintext';
 import { getTemplate } from '../utils/get-template';
 import useSnootyMetadata from '../utils/use-snooty-metadata';
-import { getCurrentLocaleFontFamilyValue } from '../utils/locale';
 import { getSiteTitle } from '../utils/get-site-title';
 import { PageContext } from '../context/page-context';
 import { useBreadcrumbs } from '../hooks/use-breadcrumbs';
 import { isBrowser } from '../utils/is-browser';
+import { TEMPLATE_CONTAINER_ID } from '../constants';
 import Widgets from './Widgets';
 import SEO from './SEO';
 import FootnoteContext from './Footnote/footnote-context';
@@ -80,8 +79,6 @@ const getAnonymousFootnoteReferences = (index, numAnonRefs) => {
   return index > numAnonRefs ? [] : [`id${index + 1}`];
 };
 
-const fontFamily = getCurrentLocaleFontFamilyValue();
-
 const DocumentBody = (props) => {
   const { location, data, pageContext } = props;
   const page = data?.page?.ast;
@@ -152,7 +149,7 @@ const DocumentBody = (props) => {
             <ImageContextProvider images={props.data?.pageImage?.images ?? []}>
               <FootnoteContext.Provider value={{ footnotes }}>
                 <PageContext.Provider value={{ page, template, slug, options: page?.options, tabsMainColumn }}>
-                  <div id="template-container">
+                  <div id={TEMPLATE_CONTAINER_ID}>
                     <Template {...props} useChatbot={useChatbot}>
                       {pageNodes.map((child, index) => (
                         <ComponentFactory
@@ -179,13 +176,6 @@ const DocumentBody = (props) => {
           </SuspenseHelper>
         </div>
       )}
-      <Global
-        styles={css`
-          #template-container *:not(:is(code, code *)) {
-            font-family: ${fontFamily};
-          }
-        `}
-      />
     </>
   );
 };
diff --git a/src/components/Footer.js b/src/components/Footer.js
index 079208dc3..77e884dc4 100644
--- a/src/components/Footer.js
+++ b/src/components/Footer.js
@@ -1,9 +1,9 @@
 import React from 'react';
 import { UnifiedFooter } from '@mdb/consistent-nav';
-import { AVAILABLE_LANGUAGES, getCurrLocale, onSelectLocale } from '../utils/locale';
+import { getAvailableLanguages, getCurrLocale, onSelectLocale } from '../utils/locale';
 
 const Footer = () => {
-  const enabledLocales = AVAILABLE_LANGUAGES.map((language) => language.localeCode);
+  const enabledLocales = getAvailableLanguages().map((language) => language.localeCode);
   return <UnifiedFooter onSelectLocale={onSelectLocale} locale={getCurrLocale()} enabledLocales={enabledLocales} />;
 };
 
diff --git a/src/components/Header/index.js b/src/components/Header/index.js
index 9bbed804e..7363f0e1a 100644
--- a/src/components/Header/index.js
+++ b/src/components/Header/index.js
@@ -5,7 +5,7 @@ import { UnifiedNav } from '@mdb/consistent-nav';
 import { SidenavMobileMenuDropdown } from '../Sidenav';
 import SiteBanner from '../Banner/SiteBanner';
 import { theme } from '../../theme/docsTheme';
-import { AVAILABLE_LANGUAGES, getCurrLocale, onSelectLocale } from '../../utils/locale';
+import { getAvailableLanguages, getCurrLocale, onSelectLocale } from '../../utils/locale';
 import { HeaderContext } from './header-context';
 
 const StyledHeaderContainer = styled.header(
@@ -21,7 +21,7 @@ const StyledHeaderContainer = styled.header(
 const Header = ({ sidenav, eol, template }) => {
   const unifiedNavProperty = 'DOCS';
 
-  const enabledLocales = AVAILABLE_LANGUAGES.map((language) => language.localeCode);
+  const enabledLocales = getAvailableLanguages().map((language) => language.localeCode);
   const { bannerContent } = useContext(HeaderContext);
 
   return (
diff --git a/src/components/Sidenav/Sidenav.js b/src/components/Sidenav/Sidenav.js
index e03c763f4..6b141503e 100644
--- a/src/components/Sidenav/Sidenav.js
+++ b/src/components/Sidenav/Sidenav.js
@@ -16,7 +16,7 @@ import { formatText } from '../../utils/format-text';
 import { TocContext } from '../../context/toc-context';
 import { VersionContext } from '../../context/version-context';
 import useSnootyMetadata from '../../utils/use-snooty-metadata';
-import { getCurrentLocaleFontFamilyValue } from '../../utils/locale';
+import { SIDE_NAV_CONTAINER_ID } from '../../constants';
 import GuidesLandingTree from './GuidesLandingTree';
 import GuidesTOCTree from './GuidesTOCTree';
 import IA from './IA';
@@ -30,8 +30,6 @@ import DocsHomeButton from './DocsHomeButton';
 
 const SIDENAV_WIDTH = 268;
 
-const fontFamily = getCurrentLocaleFontFamilyValue();
-
 // Use LG's css here to style the component without passing props
 const sideNavStyling = ({ hideMobile, isCollapsed }) => LeafyCSS`
   height: 100%;
@@ -76,12 +74,6 @@ const disableScroll = (shouldDisableScroll) => css`
   }
 `;
 
-const translatedFontFamilyStyles = css`
-  #side-nav-1 * {
-    font-family: ${fontFamily};
-  }
-`;
-
 // use eol status to determine side nav styling
 const getTopAndHeight = (topValue, template) => css`
   ${template === 'landing'
@@ -248,10 +240,10 @@ const Sidenav = ({ chapters, guides, page, pageTitle, repoBranches, slug, eol })
     <>
       <Global
         styles={css`
-          ${disableScroll(!hideMobile)} ${translatedFontFamilyStyles}
+          ${disableScroll(!hideMobile)}
         `}
       />
-      <SidenavContainer {...topValues} template={template}>
+      <SidenavContainer {...topValues} template={template} id={SIDE_NAV_CONTAINER_ID}>
         <SidenavMobileTransition hideMobile={hideMobile} isMobile={isMobile}>
           <LeafygreenSideNav
             aria-label="Side navigation"
diff --git a/src/constants.js b/src/constants.js
index 90ddb2e55..25d981dd0 100644
--- a/src/constants.js
+++ b/src/constants.js
@@ -1,3 +1,7 @@
+// Append "docs" to the beginning of SIDE_NAV_CONTAINER_ID due to differentiate from LG's internal side-nav-container testid
+export const SIDE_NAV_CONTAINER_ID = 'docs-side-nav-container';
+export const TEMPLATE_CONTAINER_ID = 'template-container';
+
 export const REF_TARGETS = {
   'compass-index': 'https://www.mongodb.com/docs/compass/current/#compass-index',
   'document-dot-notation': 'https://www.mongodb.com/docs/manual/core/document/#document-dot-notation',
diff --git a/src/layouts/index.js b/src/layouts/index.js
index 71f5e4cdc..b87662f06 100644
--- a/src/layouts/index.js
+++ b/src/layouts/index.js
@@ -11,6 +11,7 @@ import { usePresentationMode } from '../hooks/use-presentation-mode';
 import { theme } from '../theme/docsTheme';
 import useSnootyMetadata from '../utils/use-snooty-metadata';
 import { useRemoteMetadata } from '../hooks/use-remote-metadata';
+import { getAllLocaleCssStrings } from '../utils/locale';
 
 // TODO: Delete this as a part of the css cleanup
 // Currently used to preserve behavior and stop legacy css
@@ -24,6 +25,8 @@ const footerOverrides = css`
 `;
 
 const globalCSS = css`
+  ${getAllLocaleCssStrings()}
+
   body {
     font-size: 16px;
     line-height: 24px;
diff --git a/src/utils/head-scripts/redirect-based-on-lang.js b/src/utils/head-scripts/redirect-based-on-lang.js
index 4af642e73..7e3fa5b2a 100644
--- a/src/utils/head-scripts/redirect-based-on-lang.js
+++ b/src/utils/head-scripts/redirect-based-on-lang.js
@@ -9,6 +9,7 @@ function redirectBasedOnLang() {
     const storedPrefLocale = JSON.parse(localStorage.getItem('mongodb-docs'))?.['preferredLocale'];
 
     // Based on locale utils; couldn't figure out how to use imports due to how webpack attempts to resolve them
+    // PLEASE make sure this matches the AVAILABLE_LANGUAGES object, excluding English and other hidden languages
     const supportedLocaleCodes = ['zh-cn', 'ko-kr', 'pt-br'];
     const isEnglishSite = !supportedLocaleCodes.find((localeCode) =>
       window.location.pathname.startsWith('/' + localeCode)
diff --git a/src/utils/locale.js b/src/utils/locale.js
index 1a45a95a6..af5dad21d 100644
--- a/src/utils/locale.js
+++ b/src/utils/locale.js
@@ -1,4 +1,5 @@
 import { withPrefix } from 'gatsby';
+import { SIDE_NAV_CONTAINER_ID, TEMPLATE_CONTAINER_ID } from '../constants';
 import { assertTrailingSlash } from './assert-trailing-slash';
 import { isBrowser } from './is-browser';
 import { normalizePath } from './normalize-path';
@@ -17,19 +18,32 @@ export const STORAGE_KEY_PREF_LOCALE = 'preferredLocale';
 // Update this as more languages are introduced
 // Because the client-side redirect script cannot use an import, PLEASE remember to update the list of supported languages
 // in redirect-based-on-lang.js
-export const AVAILABLE_LANGUAGES = [
+const AVAILABLE_LANGUAGES = [
   { language: 'English', localeCode: 'en-us' },
-  { language: '简体中文', localeCode: 'zh-cn' },
-  { language: '한국어', localeCode: 'ko-kr' },
+  { language: '简体中文', localeCode: 'zh-cn', fontFamily: 'Noto Sans SC' },
+  { language: '한국어', localeCode: 'ko-kr', fontFamily: 'Noto Sans KR' },
   { language: 'Português', localeCode: 'pt-br' },
 ];
 
-if (process.env.GATSBY_FEATURE_SHOW_HIDDEN_LOCALES === 'true') {
-  AVAILABLE_LANGUAGES.push({ language: '日本語', localeCode: 'ja-jp' });
-}
+// Languages in current development that we do not want displayed publicly yet
+const HIDDEN_LANGUAGES = [{ language: '日本語', localeCode: 'ja-jp', fontFamily: 'Noto Sans JP' }];
+
+/**
+ * @param {boolean} forceAll - Bypasses feature flag requirements if necessary
+ * @returns An array of languages supported for translation
+ */
+export const getAvailableLanguages = (forceAll = false) => {
+  const langs = [...AVAILABLE_LANGUAGES];
+
+  if (forceAll || process.env.GATSBY_FEATURE_SHOW_HIDDEN_LOCALES === 'true') {
+    langs.push(...HIDDEN_LANGUAGES);
+  }
+
+  return langs;
+};
 
 const validateLocaleCode = (potentialCode) =>
-  !!AVAILABLE_LANGUAGES.find(({ localeCode }) => potentialCode === localeCode);
+  !!getAvailableLanguages().find(({ localeCode }) => potentialCode === localeCode);
 
 /**
  * Strips the first locale code found in the slug. This function should be used to determine the original un-localized path of a page.
@@ -60,21 +74,30 @@ const stripLocale = (slug) => {
   }
 };
 
-/**
- * Returns the font-family name or undefined as a value based on the locale code
- * returned from getCurrentLocale, undefined to tell CSS to ignore this and work as
- * normal and use LG's styles.
- *
- * This is currently for overriding font-family from LG.
- */
-export const getCurrentLocaleFontFamilyValue = () => {
-  const fontFamilyMap = {
-    'zh-cn': 'Noto Sans SC',
-    'ko-kr': 'Noto Sans KR',
-    'ja-jp': 'Noto Sans JP',
-  };
-  const locale = getCurrLocale();
-  return fontFamilyMap[locale] ? `${fontFamilyMap[locale]}` : undefined;
+export const getAllLocaleCssStrings = () => {
+  const strings = [];
+  // We want to bypass feature flag requirements to ensure fonts for hidden languages are always included
+  const allLangs = getAvailableLanguages(true);
+
+  allLangs.forEach(({ localeCode, fontFamily }) => {
+    if (!fontFamily) {
+      return;
+    }
+    const [languageCode] = localeCode.split('-');
+    // Only check that languageCode is in the beginning to be flexible when region code is capitalized
+    // For example: zh-cn and zh-CN will be treated the same.
+    // We want to target everything except for inline code, code blocks, and the consistent-nav components
+    strings.push(`
+      html[lang^=${languageCode}] {
+        #${TEMPLATE_CONTAINER_ID} *:not(:is(code, code *)),
+        #${SIDE_NAV_CONTAINER_ID} * {
+          font-family: ${fontFamily};
+        }
+      }
+    `);
+  });
+
+  return strings;
 };
 
 /**
@@ -136,7 +159,7 @@ export const getLocaleMapping = (siteUrl, slug) => {
   const normalizedSiteUrl = siteUrl?.endsWith('/') ? siteUrl.slice(0, -1) : siteUrl;
   const localeHrefMap = {};
 
-  AVAILABLE_LANGUAGES.forEach(({ localeCode }) => {
+  getAvailableLanguages().forEach(({ localeCode }) => {
     const localizedPath = localizePath(slugForUrl, localeCode);
     const targetUrl = normalizedSiteUrl + localizedPath;
     localeHrefMap[localeCode] = assertTrailingSlash(targetUrl);
@@ -151,3 +174,19 @@ export const onSelectLocale = (locale) => {
   const localizedPath = localizePath(location.pathname, locale);
   window.location.href = localizedPath;
 };
+
+/**
+ * Ensures that a locale code has an all lowercase language code with an all uppercase region code,
+ * as described in https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/lang#region_subtag.
+ * @param {string} localeCode - A valid locale code with either 1 or 2 parts. Example: `zh-cn` or `zh`
+ * @returns {string | undefined}
+ */
+export const getHtmlLangFormat = (localeCode) => {
+  const parts = localeCode.split('-');
+  if (parts.length < 2) {
+    return localeCode;
+  }
+
+  const [langCode, regionCode] = parts;
+  return `${langCode.toLowerCase()}-${regionCode.toUpperCase()}`;
+};
diff --git a/tests/unit/Head.test.js b/tests/unit/Head.test.js
index 3c5a3ecb2..bd43506c0 100644
--- a/tests/unit/Head.test.js
+++ b/tests/unit/Head.test.js
@@ -4,7 +4,7 @@ import { Head } from '../../src/components/DocumentBody';
 import mockStaticQuery from '../utils/mockStaticQuery';
 import * as siteMetadata from '../../src/hooks/use-site-metadata';
 import useSnootyMetadata from '../../src/utils/use-snooty-metadata';
-import { AVAILABLE_LANGUAGES } from '../../src/utils/locale';
+import { getAvailableLanguages } from '../../src/utils/locale';
 import { DOTCOM_BASE_URL } from '../../src/utils/base-url';
 import mockCompleteEOLPageContext from './data/CompleteEOLPageContext.json';
 import mockEOLSnootyMetadata from './data/EOLSnootyMetadata.json';
@@ -223,7 +223,7 @@ describe('Head', () => {
       const mockData = { ...mockHeadPageContext.data };
       const { container } = render(<Head pageContext={mockPageContext} data={mockData} />);
       const hrefLangLinks = container.querySelectorAll('link.sl_opaque');
-      expect(hrefLangLinks).toHaveLength(AVAILABLE_LANGUAGES.length);
+      expect(hrefLangLinks).toHaveLength(getAvailableLanguages().length);
       expect(hrefLangLinks).toMatchSnapshot();
     });
   });
diff --git a/tests/unit/utils/locale.test.js b/tests/unit/utils/locale.test.js
index 45f52058b..518ec5343 100644
--- a/tests/unit/utils/locale.test.js
+++ b/tests/unit/utils/locale.test.js
@@ -1,4 +1,4 @@
-import { AVAILABLE_LANGUAGES, getLocaleMapping, localizePath } from '../../../src/utils/locale';
+import { getAvailableLanguages, getHtmlLangFormat, getLocaleMapping, localizePath } from '../../../src/utils/locale';
 
 describe('getLocaleMapping', () => {
   it.each([
@@ -7,7 +7,7 @@ describe('getLocaleMapping', () => {
     ['https://www.mongodb.com', 'introduction'],
   ])('returns a valid mapping of URLs', (siteUrl, slug) => {
     const mapping = getLocaleMapping(siteUrl, slug);
-    expect(Object.keys(mapping)).toHaveLength(AVAILABLE_LANGUAGES.length);
+    expect(Object.keys(mapping)).toHaveLength(getAvailableLanguages().length);
     expect(mapping).toMatchSnapshot();
   });
 });
@@ -77,3 +77,14 @@ describe('localizePath', () => {
     expect(res).toEqual(expectedRes);
   });
 });
+
+describe('getHtmlLangFormat', () => {
+  it.each([
+    ['zh-cn', 'zh-CN'],
+    ['zh-CN', 'zh-CN'],
+    ['zh', 'zh'],
+  ])('transforms %s into %s', (input, expectedRes) => {
+    const res = getHtmlLangFormat(input);
+    expect(res).toEqual(expectedRes);
+  });
+});