From 996b1151992592f56e1f48803371442362051e62 Mon Sep 17 00:00:00 2001
From: Yangshun Tay <tay.yang.shun@gmail.com>
Date: Tue, 18 Feb 2020 21:29:23 +0800
Subject: [PATCH] misc(v2): clean up comments in code (#2294)

---
 packages/docusaurus-init/src/index.ts         | 12 +++----
 packages/docusaurus-mdx-loader/src/index.js   |  5 +--
 .../src/remark/rightToc/search.js             |  5 +--
 .../src/blogUtils.ts                          |  5 ++-
 .../src/index.ts                              | 14 +++++---
 .../src/markdownLoader.ts                     |  3 +-
 .../src/index.ts                              | 34 ++++++++++--------
 .../src/lastUpdate.ts                         |  3 +-
 .../src/markdown/linkify.ts                   |  1 +
 .../src/metadata.ts                           | 13 ++++---
 .../src/sidebars.ts                           | 14 ++++----
 .../src/version.ts                            | 17 +++++----
 .../src/analytics.js                          |  3 +-
 .../src/index.js                              |  2 ++
 .../src/index.js                              |  1 +
 .../src/index.ts                              |  1 +
 .../docusaurus-plugin-sitemap/src/index.ts    |  6 ++--
 .../docusaurus-preset-classic/src/index.js    |  5 ++-
 .../src/theme/DocSidebar/index.js             |  2 +-
 .../src/theme/SearchBar.js                    |  2 +-
 .../src/index.js                              |  3 +-
 .../src/index.js                              |  4 +--
 .../src/theme/SearchBar/index.js              |  7 ++--
 packages/docusaurus-utils/src/index.ts        | 36 +++++++++++--------
 packages/docusaurus/src/client/docusaurus.js  | 19 +++++-----
 .../src/client/exports/ComponentCreator.js    | 10 +++---
 .../docusaurus/src/client/exports/Link.js     | 14 ++++----
 .../exports/{utils.js => isInternalUrl.js}    |  0
 .../src/client/exports/useBaseUrl.js          |  2 ++
 packages/docusaurus/src/client/flat.js        |  1 +
 packages/docusaurus/src/client/prefetch.js    | 20 ++++++-----
 packages/docusaurus/src/client/preload.js     |  7 ++--
 packages/docusaurus/src/client/serverEntry.js |  7 ++--
 packages/docusaurus/src/commands/build.ts     | 13 ++++---
 packages/docusaurus/src/commands/deploy.ts    | 26 ++++++++------
 packages/docusaurus/src/commands/external.ts  |  4 ++-
 packages/docusaurus/src/commands/start.ts     | 10 +++---
 packages/docusaurus/src/commands/swizzle.ts   |  2 +-
 packages/docusaurus/src/server/config.ts      |  3 ++
 .../docusaurus/src/server/html-tags/index.ts  |  1 +
 packages/docusaurus/src/server/index.ts       | 14 ++++----
 packages/docusaurus/src/server/loadSetup.ts   |  2 +-
 .../docusaurus/src/server/plugins/index.ts    | 26 ++++++++------
 .../docusaurus/src/server/plugins/init.ts     |  4 ++-
 packages/docusaurus/src/server/routes.ts      |  4 +--
 45 files changed, 233 insertions(+), 154 deletions(-)
 rename packages/docusaurus/src/client/exports/{utils.js => isInternalUrl.js} (100%)

diff --git a/packages/docusaurus-init/src/index.ts b/packages/docusaurus-init/src/index.ts
index 5a761a3baaf8..d3cdc7537f22 100644
--- a/packages/docusaurus-init/src/index.ts
+++ b/packages/docusaurus-init/src/index.ts
@@ -50,7 +50,7 @@ export async function init(
 
   let name = siteName;
 
-  // Prompt if siteName is not passed from CLI
+  // Prompt if siteName is not passed from CLI.
   if (!name) {
     const {name: promptedName} = await inquirer.prompt({
       type: 'input',
@@ -71,7 +71,7 @@ export async function init(
   }
 
   let template = reqTemplate;
-  // Prompt if template is not provided from CLI
+  // Prompt if template is not provided from CLI.
   if (!template) {
     const {template: promptedTemplate} = await inquirer.prompt({
       type: 'list',
@@ -82,7 +82,7 @@ export async function init(
     template = promptedTemplate;
   }
 
-  // If user choose Git repository, we'll prompt for the url
+  // If user choose Git repository, we'll prompt for the url.
   if (template === gitChoice) {
     const {gitRepoUrl} = await inquirer.prompt({
       type: 'input',
@@ -112,7 +112,7 @@ export async function init(
       throw new Error(chalk.red(`Cloning Git template: ${template} failed!`));
     }
   } else if (template && templates.includes(template)) {
-    // Docusaurus templates
+    // Docusaurus templates.
     try {
       await fs.copy(path.resolve(templatesDir, template), dest);
     } catch (err) {
@@ -125,7 +125,7 @@ export async function init(
     throw new Error('Invalid template');
   }
 
-  // Update package.json info
+  // Update package.json info.
   try {
     await updatePkg(path.join(dest, 'package.json'), {
       name: kebabCase(name),
@@ -137,7 +137,7 @@ export async function init(
     throw err;
   }
 
-  // We need to Rename the gitignore file to .gitignore
+  // We need to rename the gitignore file to .gitignore
   if (
     !fs.pathExistsSync(path.join(dest, '.gitignore')) &&
     fs.pathExistsSync(path.join(dest, 'gitignore'))
diff --git a/packages/docusaurus-mdx-loader/src/index.js b/packages/docusaurus-mdx-loader/src/index.js
index 50ad93ce9b70..ca774981be31 100644
--- a/packages/docusaurus-mdx-loader/src/index.js
+++ b/packages/docusaurus-mdx-loader/src/index.js
@@ -46,12 +46,13 @@ module.exports = async function(fileString) {
 
   let exportStr = `export const frontMatter = ${stringifyObject(data)};`;
 
-  // Read metadata for this MDX and export it
+  // Read metadata for this MDX and export it.
   if (options.metadataPath && typeof options.metadataPath === 'function') {
     const metadataPath = options.metadataPath(this.resourcePath);
 
     if (metadataPath) {
-      // Add as dependency of this loader result so that we can recompile if metadata is changed
+      // Add as dependency of this loader result so that we can
+      // recompile if metadata is changed.
       this.addDependency(metadataPath);
       const metadata = await readFile(metadataPath, 'utf8');
       exportStr += `\nexport const metadata = ${metadata};`;
diff --git a/packages/docusaurus-mdx-loader/src/remark/rightToc/search.js b/packages/docusaurus-mdx-loader/src/remark/rightToc/search.js
index ad76f1edc447..da94908e138e 100644
--- a/packages/docusaurus-mdx-loader/src/remark/rightToc/search.js
+++ b/packages/docusaurus-mdx-loader/src/remark/rightToc/search.js
@@ -29,12 +29,13 @@ function toValue(node) {
       default:
     }
   }
+
   return toString(node);
 }
 
 // Visit all headings. We `slug` all headings (to account for
 // duplicates), but only take h2 and h3 headings.
-const search = node => {
+function search(node) {
   const headings = [];
   let current = -1;
   let currentDepth = 0;
@@ -65,6 +66,6 @@ const search = node => {
   visit(node, 'heading', onHeading);
 
   return headings;
-};
+}
 
 module.exports = search;
diff --git a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
index 35b4bdbdabbe..132840f1e31e 100644
--- a/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
+++ b/packages/docusaurus-plugin-content-blog/src/blogUtils.ts
@@ -18,7 +18,7 @@ export function truncate(fileString: string, truncateMarker: RegExp) {
 }
 
 // YYYY-MM-DD-{name}.mdx?
-// prefer named capture, but old Node version does not support.
+// Prefer named capture, but older Node versions do not support it.
 const FILENAME_PATTERN = /^(\d{4}-\d{1,2}-\d{1,2})-?(.*?).mdx?$/;
 
 function toUrl({date, link}: DateLink) {
@@ -111,15 +111,18 @@ export async function generateBlogPosts(
       // Extract date and title from filename.
       const match = blogFileName.match(FILENAME_PATTERN);
       let linkName = blogFileName.replace(/\.mdx?$/, '');
+
       if (match) {
         const [, dateString, name] = match;
         date = new Date(dateString);
         linkName = name;
       }
+
       // Prefer user-defined date.
       if (frontMatter.date) {
         date = new Date(frontMatter.date);
       }
+
       // Use file create time for blog.
       date = date || (await fs.stat(source)).birthtime;
       frontMatter.title = frontMatter.title || linkName;
diff --git a/packages/docusaurus-plugin-content-blog/src/index.ts b/packages/docusaurus-plugin-content-blog/src/index.ts
index 1ddfcd738768..1df2597ea063 100644
--- a/packages/docusaurus-plugin-content-blog/src/index.ts
+++ b/packages/docusaurus-plugin-content-blog/src/index.ts
@@ -41,7 +41,7 @@ const DEFAULT_OPTIONS: PluginOptions = {
   blogTagsPostsComponent: '@theme/BlogTagsPostsPage',
   remarkPlugins: [],
   rehypePlugins: [],
-  truncateMarker: /<!--\s*(truncate)\s*-->/, // Regex
+  truncateMarker: /<!--\s*(truncate)\s*-->/, // Regex.
 };
 
 function assertFeedTypes(val: any): asserts val is FeedType {
@@ -94,7 +94,7 @@ export default function pluginContentBlog(
         return null;
       }
 
-      // Colocate next and prev metadata
+      // Colocate next and prev metadata.
       blogPosts.forEach((blogPost, index) => {
         const prevItem = index > 0 ? blogPosts[index - 1] : null;
         if (prevItem) {
@@ -103,6 +103,7 @@ export default function pluginContentBlog(
             permalink: prevItem.metadata.permalink,
           };
         }
+
         const nextItem =
           index < blogPosts.length - 1 ? blogPosts[index + 1] : null;
         if (nextItem) {
@@ -168,7 +169,8 @@ export default function pluginContentBlog(
             const permalink = normalizeUrl([tagsPath, normalizedTag]);
             if (!blogTags[normalizedTag]) {
               blogTags[normalizedTag] = {
-                name: tag.toLowerCase(), // Will only use the name of the first occurrence of the tag.
+                // Will only use the name of the first occurrence of the tag.
+                name: tag.toLowerCase(),
                 items: [],
                 permalink,
               };
@@ -232,7 +234,8 @@ export default function pluginContentBlog(
         blogPosts.map(async blogPost => {
           const {id, metadata} = blogPost;
           await createData(
-            // Note that this created data path must be in sync with metadataPath provided to mdx-loader
+            // Note that this created data path must be in sync with
+            // metadataPath provided to mdx-loader.
             `${docuHash(metadata.source)}.json`,
             JSON.stringify(metadata, null, 2),
           );
@@ -374,7 +377,8 @@ export default function pluginContentBlog(
                   options: {
                     remarkPlugins,
                     rehypePlugins,
-                    // Note that metadataPath must be the same/ in-sync as the path from createData for each MDX
+                    // Note that metadataPath must be the same/in-sync as
+                    // the path from createData for each MDX.
                     metadataPath: (mdxPath: string) => {
                       const aliasedSource = aliasedSitePath(mdxPath, siteDir);
                       return path.join(
diff --git a/packages/docusaurus-plugin-content-blog/src/markdownLoader.ts b/packages/docusaurus-plugin-content-blog/src/markdownLoader.ts
index 6c3dd8127be8..f198899a8f75 100644
--- a/packages/docusaurus-plugin-content-blog/src/markdownLoader.ts
+++ b/packages/docusaurus-plugin-content-blog/src/markdownLoader.ts
@@ -16,10 +16,11 @@ export = function(fileString: string) {
 
   let finalContent = fileString;
 
-  // Truncate content if requested (e.g: file.md?truncated=true)
+  // Truncate content if requested (e.g: file.md?truncated=true).
   const {truncated} = this.resourceQuery && parseQuery(this.resourceQuery);
   if (truncated) {
     finalContent = truncate(fileString, truncateMarker);
   }
+
   return callback && callback(null, finalContent);
 } as loader.Loader;
diff --git a/packages/docusaurus-plugin-content-docs/src/index.ts b/packages/docusaurus-plugin-content-docs/src/index.ts
index d5185d123831..661fd05ba5df 100644
--- a/packages/docusaurus-plugin-content-docs/src/index.ts
+++ b/packages/docusaurus-plugin-content-docs/src/index.ts
@@ -71,7 +71,7 @@ export default function pluginContentDocs(
     'docusaurus-plugin-content-docs',
   );
 
-  // Versioning
+  // Versioning.
   const env = loadEnv(siteDir);
   const {versioning} = env;
   const {
@@ -128,7 +128,7 @@ export default function pluginContentDocs(
       const docsMetadataRaw: DocsMetadataRaw = {};
       const docsPromises = [];
 
-      // Metadata for default/ master docs files.
+      // Metadata for default/master docs files.
       const docsFiles = await globby(include, {
         cwd: docsDir,
       });
@@ -147,7 +147,7 @@ export default function pluginContentDocs(
         ),
       );
 
-      // Metadata for versioned docs
+      // Metadata for versioned docs.
       if (versioning.enabled) {
         const versionedGlob = _.flatten(
           include.map(pattern =>
@@ -173,7 +173,7 @@ export default function pluginContentDocs(
         );
       }
 
-      // Load the sidebars & create docs ordering
+      // Load the sidebars and create docs ordering.
       const sidebarPaths = [
         sidebarPath,
         ...versionsNames.map(
@@ -185,7 +185,7 @@ export default function pluginContentDocs(
 
       await Promise.all(docsPromises);
 
-      // Construct inter-metadata relationship in docsMetadata
+      // Construct inter-metadata relationship in docsMetadata.
       const docsMetadata: DocsMetadata = {};
       const permalinkToSidebar: PermalinkToSidebar = {};
       const versionToSidebars: VersionToSidebars = {};
@@ -211,7 +211,7 @@ export default function pluginContentDocs(
           next,
         };
 
-        // sourceToPermalink and permalinkToSidebar mapping
+        // sourceToPermalink and permalinkToSidebar mapping.
         const {source, permalink, version} = docsMetadataRaw[currentID];
         sourceToPermalink[source] = permalink;
         if (sidebar) {
@@ -255,8 +255,9 @@ export default function pluginContentDocs(
         }
       };
 
-      // Transform the sidebar so that all sidebar item will be in the form of 'link' or 'category' only
-      // This is what will be passed as props to the UI component
+      // Transform the sidebar so that all sidebar item will be in the
+      // form of 'link' or 'category' only.
+      // This is what will be passed as props to the UI component.
       const docsSidebars: DocsSidebar = Object.entries(loadedSidebars).reduce(
         (acc: DocsSidebar, [sidebarId, sidebarItems]) => {
           acc[sidebarId] = sidebarItems.map(normalizeItem);
@@ -290,10 +291,12 @@ export default function pluginContentDocs(
         const routes = await Promise.all(
           metadataItems.map(async metadataItem => {
             await createData(
-              // Note that this created data path must be in sync with metadataPath provided to mdx-loader
+              // Note that this created data path must be in sync with
+              // metadataPath provided to mdx-loader.
               `${docuHash(metadataItem.source)}.json`,
               JSON.stringify(metadataItem, null, 2),
             );
+
             return {
               path: metadataItem.permalink,
               component: docItemComponent,
@@ -304,6 +307,7 @@ export default function pluginContentDocs(
             };
           }),
         );
+
         return routes.sort((a, b) =>
           a.path > b.path ? 1 : b.path > a.path ? -1 : 0,
         );
@@ -331,8 +335,8 @@ export default function pluginContentDocs(
         });
       };
 
-      // If versioning is enabled, we cleverly chunk the generated routes to be by version
-      // and pick only needed base metadata
+      // If versioning is enabled, we cleverly chunk the generated routes
+      // to be by version and pick only needed base metadata.
       if (versioning.enabled) {
         const docsMetadataByVersion = _.groupBy(
           Object.values(content.docsMetadata),
@@ -365,8 +369,9 @@ export default function pluginContentDocs(
               version,
             };
 
-            // We want latest version route config to be placed last in the generated routeconfig.
-            // Otherwise, `/docs/next/foo` will match `/docs/:route` instead of `/docs/next/:route`
+            // We want latest version route config to be placed last in the
+            // generated routeconfig. Otherwise, `/docs/next/foo` will match
+            // `/docs/:route` instead of `/docs/next/:route`.
             return addBaseRoute(
               docsBaseRoute,
               docsBaseMetadata,
@@ -410,7 +415,8 @@ export default function pluginContentDocs(
                     remarkPlugins,
                     rehypePlugins,
                     metadataPath: (mdxPath: string) => {
-                      // Note that metadataPath must be the same/ in-sync as the path from createData for each MDX
+                      // Note that metadataPath must be the same/in-sync as
+                      // the path from createData for each MDX.
                       const aliasedSource = aliasedSitePath(mdxPath, siteDir);
                       return path.join(
                         dataDir,
diff --git a/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts b/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts
index bfd8899bbf69..07cbb129dc51 100644
--- a/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts
+++ b/packages/docusaurus-plugin-content-docs/src/lastUpdate.ts
@@ -31,7 +31,8 @@ export default async function getFileLastUpdate(
       : {timestamp: +temp[1], author: temp[2]};
   }
 
-  // Wrap in try/catch in case the shell commands fail (e.g. project doesn't use Git, etc).
+  // Wrap in try/catch in case the shell commands fail
+  // (e.g. project doesn't use Git, etc).
   try {
     if (!shell.which('git')) {
       if (!showedGitRequirementError) {
diff --git a/packages/docusaurus-plugin-content-docs/src/markdown/linkify.ts b/packages/docusaurus-plugin-content-docs/src/markdown/linkify.ts
index c53f76d3f30d..6a937767f83b 100644
--- a/packages/docusaurus-plugin-content-docs/src/markdown/linkify.ts
+++ b/packages/docusaurus-plugin-content-docs/src/markdown/linkify.ts
@@ -64,6 +64,7 @@ export default function(
       }
       return modifiedLine;
     });
+
     content = lines.join('\n');
   }
 
diff --git a/packages/docusaurus-plugin-content-docs/src/metadata.ts b/packages/docusaurus-plugin-content-docs/src/metadata.ts
index c73353f5331c..90e420e913c5 100644
--- a/packages/docusaurus-plugin-content-docs/src/metadata.ts
+++ b/packages/docusaurus-plugin-content-docs/src/metadata.ts
@@ -32,7 +32,7 @@ async function lastUpdated(
 ): Promise<LastUpdateData> {
   const {showLastUpdateAuthor, showLastUpdateTime} = options;
   if (showLastUpdateAuthor || showLastUpdateTime) {
-    // Use fake data in dev for faster development
+    // Use fake data in dev for faster development.
     const fileLastUpdateData =
       process.env.NODE_ENV === 'production'
         ? await lastUpdate(filePath)
@@ -49,6 +49,7 @@ async function lastUpdated(
       };
     }
   }
+
   return {};
 }
 
@@ -83,7 +84,7 @@ export default async function processMetadata({
     }
   }
 
-  // The version portion of the url path. Eg: 'next', '1.0.0', and ''
+  // The version portion of the url path. Eg: 'next', '1.0.0', and ''.
   const versionPath =
     version && version !== versioning.latestVersion ? version : '';
 
@@ -112,7 +113,7 @@ export default async function processMetadata({
 
   const description: string = frontMatter.description || excerpt;
 
-  // The last portion of the url path. Eg: 'foo/bar', 'bar'
+  // The last portion of the url path. Eg: 'foo/bar', 'bar'.
   const routePath =
     version && version !== 'next'
       ? id.replace(new RegExp(`^version-${version}/`), '')
@@ -126,8 +127,10 @@ export default async function processMetadata({
 
   const {lastUpdatedAt, lastUpdatedBy} = await lastUpdatedPromise;
 
-  // Assign all of object properties during instantiation (if possible) for NodeJS optimization
-  // Adding properties to object after instantiation will cause hidden class transitions.
+  // Assign all of object properties during instantiation (if possible) for
+  // NodeJS optimization.
+  // Adding properties to object after instantiation will cause hidden
+  // class transitions.
   const metadata: MetadataRaw = {
     id,
     title,
diff --git a/packages/docusaurus-plugin-content-docs/src/sidebars.ts b/packages/docusaurus-plugin-content-docs/src/sidebars.ts
index 475873df5304..35b12aaa2fe9 100644
--- a/packages/docusaurus-plugin-content-docs/src/sidebars.ts
+++ b/packages/docusaurus-plugin-content-docs/src/sidebars.ts
@@ -18,7 +18,7 @@ import {
 } from './types';
 
 /**
- * Check that item contains only allowed keys
+ * Check that item contains only allowed keys.
  */
 function assertItem(item: Object, keys: string[]): void {
   const unknownKeys = Object.keys(item).filter(
@@ -72,8 +72,8 @@ function assertIsLink(item: any): asserts item is SidebarItemLink {
 }
 
 /**
- * Normalizes recursively item and all its children. Ensures, that at the end
- * each item will be an object with the corresponding type
+ * Normalizes recursively item and all its children. Ensures that at the end
+ * each item will be an object with the corresponding type.
  */
 function normalizeItem(item: SidebarItemRaw): SidebarItem {
   if (typeof item === 'string') {
@@ -102,7 +102,7 @@ function normalizeItem(item: SidebarItemRaw): SidebarItem {
 }
 
 /**
- * Converts sidebars object to mapping to arrays of sidebar item objects
+ * Converts sidebars object to mapping to arrays of sidebar item objects.
  */
 function normalizeSidebar(sidebars: SidebarRaw): Sidebar {
   return Object.entries(sidebars).reduce(
@@ -110,7 +110,7 @@ function normalizeSidebar(sidebars: SidebarRaw): Sidebar {
       let normalizedSidebar: SidebarItemRaw[];
 
       if (!Array.isArray(sidebar)) {
-        // convert sidebar to a more generic structure
+        // Convert sidebar to a more generic structure.
         normalizedSidebar = Object.entries(sidebar).map(([label, items]) => ({
           type: 'category',
           label,
@@ -129,11 +129,13 @@ function normalizeSidebar(sidebars: SidebarRaw): Sidebar {
 }
 
 export default function loadSidebars(sidebarPaths?: string[]): Sidebar {
-  // We don't want sidebars to be cached because of hotreloading.
+  // We don't want sidebars to be cached because of hot reloading.
   let allSidebars: SidebarRaw = {};
+
   if (!sidebarPaths || !sidebarPaths.length) {
     return {} as Sidebar;
   }
+
   sidebarPaths.map(sidebarPath => {
     if (sidebarPath && fs.existsSync(sidebarPath)) {
       const sidebar = importFresh(sidebarPath) as SidebarRaw;
diff --git a/packages/docusaurus-plugin-content-docs/src/version.ts b/packages/docusaurus-plugin-content-docs/src/version.ts
index bed9f696e7d5..80a148545e15 100644
--- a/packages/docusaurus-plugin-content-docs/src/version.ts
+++ b/packages/docusaurus-plugin-content-docs/src/version.ts
@@ -25,18 +25,21 @@ export function docsVersion(
       'No version tag specified!. Pass the version you wish to create as an argument. Ex: 1.0.0',
     );
   }
+
   if (version.includes('/') || version.includes('\\')) {
     throw new Error(
       `Invalid version tag specified! Do not include slash (/) or (\\). Try something like: 1.0.0`,
     );
   }
+
   if (version.length > 32) {
     throw new Error(
       'Invalid version tag specified! Length must <= 32 characters. Try something like: 1.0.0',
     );
   }
 
-  // Since we are going to create `version-${version}` folder, we need to make sure its a valid path name
+  // Since we are going to create `version-${version}` folder, we need to make
+  // sure it's a valid pathname.
   if (/[<>:"\/\\|?*\x00-\x1F]/g.test(version)) {
     throw new Error(
       'Invalid version tag specified! Please ensure its a valid pathname too. Try something like: 1.0.0',
@@ -49,14 +52,14 @@ export function docsVersion(
     );
   }
 
-  // Load existing versions
+  // Load existing versions.
   let versions = [];
   const versionsJSONFile = getVersionsJSONFile(siteDir);
   if (fs.existsSync(versionsJSONFile)) {
     versions = JSON.parse(fs.readFileSync(versionsJSONFile, 'utf8'));
   }
 
-  // Check if version already exist
+  // Check if version already exists.
   if (versions.includes(version)) {
     throw new Error(
       'This version already exists!. Use a version tag that does not already exist.',
@@ -65,7 +68,7 @@ export function docsVersion(
 
   const {path: docsPath, sidebarPath} = options;
 
-  // Copy docs files
+  // Copy docs files.
   const docsDir = path.join(siteDir, docsPath);
   if (fs.existsSync(docsDir) && fs.readdirSync(docsDir).length > 0) {
     const versionedDir = getVersionedDocsDir(siteDir);
@@ -75,11 +78,11 @@ export function docsVersion(
     throw new Error('There is no docs to version !');
   }
 
-  // Load current sidebar and create a new versioned sidebars file
+  // Load current sidebar and create a new versioned sidebars file.
   if (fs.existsSync(sidebarPath)) {
     const loadedSidebars: Sidebar = loadSidebars([sidebarPath]);
 
-    // Transform id in original sidebar to versioned id
+    // Transform id in original sidebar to versioned id.
     const normalizeItem = (item: SidebarItem): SidebarItem => {
       switch (item.type) {
         case 'category':
@@ -117,7 +120,7 @@ export function docsVersion(
     );
   }
 
-  // update versions.json file
+  // Update versions.json file.
   versions.unshift(version);
   fs.ensureDirSync(path.dirname(versionsJSONFile));
   fs.writeFileSync(versionsJSONFile, `${JSON.stringify(versions, null, 2)}\n`);
diff --git a/packages/docusaurus-plugin-google-analytics/src/analytics.js b/packages/docusaurus-plugin-google-analytics/src/analytics.js
index 9b7b31b8707f..38d9edf6eaab 100644
--- a/packages/docusaurus-plugin-google-analytics/src/analytics.js
+++ b/packages/docusaurus-plugin-google-analytics/src/analytics.js
@@ -15,7 +15,8 @@ export default (function() {
       // Set page so that subsequent hits on this page are attributed
       // to this page. This is recommended for Single-page Applications.
       window.ga('set', 'page', location.pathname);
-      // Always refer to the variable on window in-case it gets overridden elsewhere.
+      // Always refer to the variable on window in-case it gets
+      // overridden elsewhere.
       window.ga('send', 'pageview');
     },
   };
diff --git a/packages/docusaurus-plugin-google-analytics/src/index.js b/packages/docusaurus-plugin-google-analytics/src/index.js
index 4a2f23323359..8c2e8aa57135 100644
--- a/packages/docusaurus-plugin-google-analytics/src/index.js
+++ b/packages/docusaurus-plugin-google-analytics/src/index.js
@@ -26,7 +26,9 @@ module.exports = function(context) {
         'Please ensure this is not a mistake.',
     );
   }
+
   const isProd = process.env.NODE_ENV === 'production';
+
   return {
     name: 'docusaurus-plugin-google-analytics',
 
diff --git a/packages/docusaurus-plugin-google-gtag/src/index.js b/packages/docusaurus-plugin-google-gtag/src/index.js
index eba2b605e43d..49dc71d8e090 100644
--- a/packages/docusaurus-plugin-google-gtag/src/index.js
+++ b/packages/docusaurus-plugin-google-gtag/src/index.js
@@ -28,6 +28,7 @@ module.exports = function(context) {
   }
 
   const isProd = process.env.NODE_ENV === 'production';
+
   return {
     name: 'docusaurus-plugin-google-gtag',
 
diff --git a/packages/docusaurus-plugin-ideal-image/src/index.ts b/packages/docusaurus-plugin-ideal-image/src/index.ts
index 4a5ae9eec55b..cda524d41f50 100644
--- a/packages/docusaurus-plugin-ideal-image/src/index.ts
+++ b/packages/docusaurus-plugin-ideal-image/src/index.ts
@@ -12,6 +12,7 @@ import path from 'path';
 
 export default function(_context: LoadContext, options: PluginOptions) {
   const isProd = process.env.NODE_ENV === 'production';
+
   return {
     name: 'docusaurus-plugin-ideal-image',
 
diff --git a/packages/docusaurus-plugin-sitemap/src/index.ts b/packages/docusaurus-plugin-sitemap/src/index.ts
index 0394d40eb08a..67121cadc25d 100644
--- a/packages/docusaurus-plugin-sitemap/src/index.ts
+++ b/packages/docusaurus-plugin-sitemap/src/index.ts
@@ -12,7 +12,7 @@ import createSitemap from './createSitemap';
 import {LoadContext, Props} from '@docusaurus/types';
 
 const DEFAULT_OPTIONS: PluginOptions = {
-  cacheTime: 600 * 1000, // 600 sec - cache purge period
+  cacheTime: 600 * 1000, // 600 sec - cache purge period.
   changefreq: 'weekly',
   priority: 0.5,
 };
@@ -27,14 +27,14 @@ export default function pluginSitemap(
     name: 'docusaurus-plugin-sitemap',
 
     async postBuild({siteConfig, routesPaths, outDir}: Props) {
-      // Generate sitemap
+      // Generate sitemap.
       const generatedSitemap = createSitemap(
         siteConfig,
         routesPaths,
         options,
       ).toString();
 
-      // Write sitemap file
+      // Write sitemap file.
       const sitemapPath = path.join(outDir, 'sitemap.xml');
       fs.writeFile(sitemapPath, generatedSitemap, err => {
         if (err) {
diff --git a/packages/docusaurus-preset-classic/src/index.js b/packages/docusaurus-preset-classic/src/index.js
index 8e73325a4342..40493af7e0c7 100644
--- a/packages/docusaurus-preset-classic/src/index.js
+++ b/packages/docusaurus-preset-classic/src/index.js
@@ -12,15 +12,18 @@ const addAdmonitions = pluginOptions => {
       remarkPlugins: [admonitions],
     };
   }
+
   if (pluginOptions.admonitions === false) {
     return pluginOptions;
   }
+
   const admonitionsOptions = {
     remarkPlugins: (pluginOptions.remarkPlugins || []).concat([
       admonitions,
       pluginOptions.admonitions || {},
     ]),
   };
+
   return {
     ...pluginOptions,
     ...admonitionsOptions,
@@ -39,7 +42,7 @@ module.exports = function preset(context, opts = {}) {
   return {
     themes: [
       ['@docusaurus/theme-classic', opts.theme],
-      // Don't add this if algolia config is not defined
+      // Don't add this if algolia config is not defined.
       algolia && '@docusaurus/theme-search-algolia',
     ],
     plugins: [
diff --git a/packages/docusaurus-theme-classic/src/theme/DocSidebar/index.js b/packages/docusaurus-theme-classic/src/theme/DocSidebar/index.js
index a994194366d0..aae1032a2ac5 100644
--- a/packages/docusaurus-theme-classic/src/theme/DocSidebar/index.js
+++ b/packages/docusaurus-theme-classic/src/theme/DocSidebar/index.js
@@ -11,7 +11,7 @@ import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 import useLockBodyScroll from '@theme/hooks/useLockBodyScroll';
 import Link from '@docusaurus/Link';
-import isInternalUrl from '@docusaurus/utils'; // eslint-disable-line import/no-extraneous-dependencies
+import isInternalUrl from '@docusaurus/isInternalUrl';
 
 import styles from './styles.module.css';
 
diff --git a/packages/docusaurus-theme-classic/src/theme/SearchBar.js b/packages/docusaurus-theme-classic/src/theme/SearchBar.js
index b2c2e8a7e2b1..04e60239ece0 100644
--- a/packages/docusaurus-theme-classic/src/theme/SearchBar.js
+++ b/packages/docusaurus-theme-classic/src/theme/SearchBar.js
@@ -5,4 +5,4 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-export {default} from '@docusaurus/Noop';
+export {default} from '@docusaurus/noop';
diff --git a/packages/docusaurus-theme-live-codeblock/src/index.js b/packages/docusaurus-theme-live-codeblock/src/index.js
index a210d030fad6..530adae30a93 100644
--- a/packages/docusaurus-theme-live-codeblock/src/index.js
+++ b/packages/docusaurus-theme-live-codeblock/src/index.js
@@ -19,7 +19,8 @@ module.exports = function() {
       return {
         resolve: {
           alias: {
-            // fork of Buble which removes Buble's large dependency and weighs in at a smaller size of ~51kB
+            // fork of Buble which removes Buble's large dependency and weighs in
+            // at a smaller size of ~51kB
             // https://github.com/FormidableLabs/react-live#what-bundle-size-can-i-expect
             buble: '@philpl/buble',
           },
diff --git a/packages/docusaurus-theme-search-algolia/src/index.js b/packages/docusaurus-theme-search-algolia/src/index.js
index 1945549cb852..4f5b4f17954e 100644
--- a/packages/docusaurus-theme-search-algolia/src/index.js
+++ b/packages/docusaurus-theme-search-algolia/src/index.js
@@ -16,7 +16,7 @@ module.exports = function() {
     },
 
     configureWebpack() {
-      // Ensure that algolia docsearch css is its own chunk
+      // Ensure that algolia docsearch styles is its own chunk.
       return {
         optimization: {
           splitChunks: {
@@ -26,7 +26,7 @@ module.exports = function() {
                 test: /algolia\.css$/,
                 chunks: `all`,
                 enforce: true,
-                // Set priority higher than docusaurus single-css extraction
+                // Set priority higher than docusaurus single-css extraction.
                 priority: 60,
               },
             },
diff --git a/packages/docusaurus-theme-search-algolia/src/theme/SearchBar/index.js b/packages/docusaurus-theme-search-algolia/src/theme/SearchBar/index.js
index 3c9bd3bf975e..f4be9987c84c 100644
--- a/packages/docusaurus-theme-search-algolia/src/theme/SearchBar/index.js
+++ b/packages/docusaurus-theme-search-algolia/src/theme/SearchBar/index.js
@@ -33,12 +33,13 @@ const Search = props => {
       // navigation and avoiding a full page refresh.
       handleSelected: (_input, _event, suggestion) => {
         // Use an anchor tag to parse the absolute url into a relative url
-        // Alternatively, we can use new URL(suggestion.url) but its not supported in IE
+        // Alternatively, we can use new URL(suggestion.url) but it's not supported in IE.
         const a = document.createElement('a');
         a.href = suggestion.url;
 
-        // Algolia use closest parent element id #__docusaurus when a h1 page title does not have an id
-        // So, we can safely remove it. See https://github.com/facebook/docusaurus/issues/1828 for more details.
+        // Algolia use closest parent element id #__docusaurus when a h1 page title does
+        // not have an id, so we can safely remove it.
+        // See https://github.com/facebook/docusaurus/issues/1828 for more details.
         const routePath =
           `#__docusaurus` === a.hash
             ? `${a.pathname}`
diff --git a/packages/docusaurus-utils/src/index.ts b/packages/docusaurus-utils/src/index.ts
index 24c6d63eb9d3..b46b96252234 100644
--- a/packages/docusaurus-utils/src/index.ts
+++ b/packages/docusaurus-utils/src/index.ts
@@ -29,9 +29,9 @@ export async function generate(
 
   let lastHash = fileHash.get(filepath);
 
-  // If file already exist but its not in runtime cache hash yet,
+  // If file already exists but its not in runtime cache yet,
   // we try to calculate the content hash and then compare
-  // This is to avoid unnecessary overwrite and we can reuse old file
+  // This is to avoid unnecessary overwriting and we can reuse old file.
   if (!lastHash && fs.existsSync(filepath)) {
     const lastContent = await fs.readFile(filepath, 'utf8');
     lastHash = createHash('md5')
@@ -64,7 +64,8 @@ const indexRE = /(^|.*\/)index\.(md|js|jsx|ts|tsx)$/i;
 const extRE = /\.(md|js)$/;
 
 /**
- * Convert filepath to url path. Example: 'index.md' -> '/', 'foo/bar.js' -> '/foo/bar',
+ * Convert filepath to url path.
+ * Example: 'index.md' -> '/', 'foo/bar.js' -> '/foo/bar',
  */
 export function fileToPath(file: string): string {
   if (indexRE.test(file)) {
@@ -81,7 +82,8 @@ export function encodePath(userpath: string): string {
 }
 
 /**
- * Given an input string, convert to kebab-case and append a hash. Avoid str collision
+ * Given an input string, convert to kebab-case and append a hash.
+ * Avoid str collision.
  */
 export function docuHash(str: string): string {
   if (str === '/') {
@@ -95,7 +97,8 @@ export function docuHash(str: string): string {
 }
 
 /**
- * Generate unique React Component Name. E.g: /foo-bar -> FooBar096
+ * Generate unique React Component Name.
+ * E.g: /foo-bar -> FooBar096
  */
 export function genComponentName(pagePath: string): string {
   if (pagePath === '/') {
@@ -107,7 +110,8 @@ export function genComponentName(pagePath: string): string {
 }
 
 /**
- * Convert Windows backslash paths to posix style paths. E.g: endi\\lie -> endi/lie
+ * Convert Windows backslash paths to posix style paths.
+ * E.g: endi\\lie -> endi/lie
  */
 export function posixPath(str: string): string {
   const isExtendedLengthPath = /^\\\\\?\\/.test(str);
@@ -121,7 +125,7 @@ export function posixPath(str: string): string {
 
 const chunkNameCache = new Map();
 /**
- * Generate unique chunk name given a module path
+ * Generate unique chunk name given a module path.
  */
 export function genChunkName(
   modulePath: string,
@@ -164,7 +168,7 @@ export function idx(target: any, keyPaths?: string | (string | number)[]): any {
 }
 
 /**
- * Given a filepath and dirpath, get the first directory
+ * Given a filepath and dirpath, get the first directory.
  */
 export function getSubFolder(file: string, refDir: string): string | null {
   const separator = escapeStringRegexp(path.sep);
@@ -193,6 +197,7 @@ export function parse(
         .shift();
     },
   };
+
   const {data: frontMatter, content, excerpt} = matter(fileString, options);
   return {frontMatter, content, excerpt};
 }
@@ -238,27 +243,30 @@ export function normalizeUrl(rawUrls: string[]): string {
   }
 
   let str = resultArray.join('/');
-  // Each input component is now separated by a single slash except the possible first plain protocol part.
+  // Each input component is now separated by a single slash
+  // except the possible first plain protocol part.
 
-  // remove trailing slash before parameters or hash
+  // Remove trailing slash before parameters or hash.
   str = str.replace(/\/(\?|&|#[^!])/g, '$1');
 
-  // replace ? in parameters with &
+  // Replace ? in parameters with &.
   const parts = str.split('?');
   str = parts.shift() + (parts.length > 0 ? '?' : '') + parts.join('&');
 
-  // dedupe forward slashes
+  // Dedupe forward slashes.
   str = str.replace(/^\/+/, '/');
 
   return str;
 }
 
 /**
- * Alias filepath relative to site directory, very useful so that we don't expose user's site structure.
+ * Alias filepath relative to site directory, very useful so that we
+ * don't expose user's site structure.
  * Example: some/path/to/website/docs/foo.md -> @site/docs/foo.md
  */
 export function aliasedSitePath(filePath: string, siteDir: string) {
   const relativePath = path.relative(siteDir, filePath);
-  // Cannot use path.join() as it resolves '../' and removes the '@site'. Let webpack loader resolve it.
+  // Cannot use path.join() as it resolves '../' and removes
+  // the '@site'. Let webpack loader resolve it.
   return `@site/${relativePath}`;
 }
diff --git a/packages/docusaurus/src/client/docusaurus.js b/packages/docusaurus/src/client/docusaurus.js
index 5a3efce118d0..5dca00f90c68 100644
--- a/packages/docusaurus/src/client/docusaurus.js
+++ b/packages/docusaurus/src/client/docusaurus.js
@@ -15,7 +15,7 @@ const fetched = {};
 const loaded = {};
 
 const isSlowConnection = () => {
-  // if user is on slow or constrained connection
+  // If user is on slow or constrained connection.
   if (`connection` in navigator) {
     if (
       (navigator.connection.effectiveType || ``).indexOf(`2g`) !== -1 &&
@@ -37,10 +37,10 @@ const docusaurus = {
     if (!canPrefetch(routePath)) {
       return false;
     }
-    // prevent future duplicate prefetch of routePath
+    // Prevent future duplicate prefetch of routePath.
     fetched[routePath] = true;
 
-    // Find all webpack chunk names needed
+    // Find all webpack chunk names needed.
     const matches = matchRoutes(routes, routePath);
     const chunkNamesNeeded = matches.reduce((arr, match) => {
       const chunk = routesChunkNames[match.route.path];
@@ -52,25 +52,28 @@ const docusaurus = {
       return arr.concat(chunkNames);
     }, []);
 
-    // Prefetch all webpack chunk assets file needed
+    // Prefetch all webpack chunk assets file needed.
     chunkNamesNeeded.forEach(chunkName => {
-      // "__webpack_require__.gca" is a custom function provided by ChunkAssetPlugin
-      // Pass it the chunkName or chunkId you want to load and it will return the URL for that chunk
+      // "__webpack_require__.gca" is a custom function provided by ChunkAssetPlugin.
+      // Pass it the chunkName or chunkId you want to load and it will return the URL for that chunk.
       // eslint-disable-next-line no-undef
       const chunkAsset = __webpack_require__.gca(chunkName);
 
-      // In some cases, webpack might decide to optimize further & hence the chunk asssets are merged to another chunk/previous chunk
-      // Hence, we can safely filter it out/ dont need to load it
+      // In some cases, webpack might decide to optimize further & hence the chunk assets are merged to another chunk/previous chunk.
+      // Hence, we can safely filter it out/don't need to load it.
       if (chunkAsset && !/undefined/.test(chunkAsset)) {
         prefetchHelper(chunkAsset);
       }
     });
+
     return true;
   },
+
   preload: routePath => {
     if (!canPreload(routePath)) {
       return false;
     }
+
     loaded[routePath] = true;
     preloadHelper(routes, routePath);
     return true;
diff --git a/packages/docusaurus/src/client/exports/ComponentCreator.js b/packages/docusaurus/src/client/exports/ComponentCreator.js
index da650ad99ae9..cb5bd075c119 100644
--- a/packages/docusaurus/src/client/exports/ComponentCreator.js
+++ b/packages/docusaurus/src/client/exports/ComponentCreator.js
@@ -30,10 +30,10 @@ function ComponentCreator(path) {
   https://github.com/jamiebuilds/react-loadable#declaring-which-modules-are-being-loaded
   Example:
   - optsLoader:
-  {
-    component: () => import('./Pages.js'),
-    content.foo: () => import('./doc1.md'),
-  }
+    {
+      component: () => import('./Pages.js'),
+      content.foo: () => import('./doc1.md'),
+    }
   - optsModules: ['./Pages.js', './doc1.md']
   - optsWebpack: [require.resolveWeak('./Pages.js'), require.resolveWeak('./doc1.md')]
   */
@@ -55,7 +55,7 @@ function ComponentCreator(path) {
     modules: optsModules,
     webpack: () => optsWebpack,
     render: (loaded, props) => {
-      // clone the original object since we don't want to alter the original.
+      // Clone the original object since we don't want to alter the original.
       const loadedModules = JSON.parse(JSON.stringify(chunkNames));
       Object.keys(loaded).forEach(key => {
         let val = loadedModules;
diff --git a/packages/docusaurus/src/client/exports/Link.js b/packages/docusaurus/src/client/exports/Link.js
index bc0ab6274bcc..9a21bbc0b469 100644
--- a/packages/docusaurus/src/client/exports/Link.js
+++ b/packages/docusaurus/src/client/exports/Link.js
@@ -7,7 +7,7 @@
 
 import React, {useEffect, useRef} from 'react';
 import {NavLink} from 'react-router-dom';
-import isInternalUrl from '@docusaurus/utils';
+import isInternalUrl from '@docusaurus/isInternalUrl';
 
 function Link(props) {
   const {to, href} = props;
@@ -23,7 +23,7 @@ function Link(props) {
     io = new window.IntersectionObserver(entries => {
       entries.forEach(entry => {
         if (el === entry.target) {
-          // If element is in viewport, stop listening/observing & run callback.
+          // If element is in viewport, stop listening/observing and run callback.
           // https://developer.mozilla.org/en-US/docs/Web/API/Intersection_Observer_API
           if (entry.isIntersecting || entry.intersectionRatio > 0) {
             io.unobserve(el);
@@ -33,13 +33,14 @@ function Link(props) {
         }
       });
     });
-    // Add element to the observer
+
+    // Add element to the observer.
     io.observe(el);
   };
 
   const handleRef = ref => {
     if (IOSupported && ref && isInternal) {
-      // If IO supported and element reference found, setup Observer functionality
+      // If IO supported and element reference found, setup Observer functionality.
       handleIntersection(ref, () => {
         window.docusaurus.prefetch(targetLink);
       });
@@ -54,11 +55,12 @@ function Link(props) {
   };
 
   useEffect(() => {
-    // If IO is not supported. We prefetch by default (only once)
+    // If IO is not supported. We prefetch by default (only once).
     if (!IOSupported && isInternal) {
       window.docusaurus.prefetch(targetLink);
     }
-    // when unmount, stops intersection observer from watching
+
+    // When unmounting, stop intersection observer from watching.
     return () => {
       if (IOSupported && io) {
         io.disconnect();
diff --git a/packages/docusaurus/src/client/exports/utils.js b/packages/docusaurus/src/client/exports/isInternalUrl.js
similarity index 100%
rename from packages/docusaurus/src/client/exports/utils.js
rename to packages/docusaurus/src/client/exports/isInternalUrl.js
diff --git a/packages/docusaurus/src/client/exports/useBaseUrl.js b/packages/docusaurus/src/client/exports/useBaseUrl.js
index 4c8a6d6985ba..3ff25134061e 100644
--- a/packages/docusaurus/src/client/exports/useBaseUrl.js
+++ b/packages/docusaurus/src/client/exports/useBaseUrl.js
@@ -19,8 +19,10 @@ export default function useBaseUrl(url) {
   if (externalRegex.test(url)) {
     return url;
   }
+
   if (url.startsWith('/')) {
     return baseUrl + url.slice(1);
   }
+
   return baseUrl + url;
 }
diff --git a/packages/docusaurus/src/client/flat.js b/packages/docusaurus/src/client/flat.js
index 4d9ee5703a0a..9de53af10e76 100644
--- a/packages/docusaurus/src/client/flat.js
+++ b/packages/docusaurus/src/client/flat.js
@@ -23,6 +23,7 @@ function flat(target) {
       output[newKey] = value;
     });
   }
+
   step(target);
   return output;
 }
diff --git a/packages/docusaurus/src/client/prefetch.js b/packages/docusaurus/src/client/prefetch.js
index 5d684e68890a..86fafb8d4a70 100644
--- a/packages/docusaurus/src/client/prefetch.js
+++ b/packages/docusaurus/src/client/prefetch.js
@@ -5,10 +5,11 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-const support = function(feature) {
+function support(feature) {
   if (typeof document === 'undefined') {
     return false;
   }
+
   const fakeLink = document.createElement('link');
   try {
     if (fakeLink.relList && typeof fakeLink.relList.supports === 'function') {
@@ -17,10 +18,11 @@ const support = function(feature) {
   } catch (err) {
     return false;
   }
+
   return false;
-};
+}
 
-const linkPrefetchStrategy = function(url) {
+function linkPrefetchStrategy(url) {
   return new Promise((resolve, reject) => {
     if (typeof document === 'undefined') {
       reject();
@@ -39,9 +41,9 @@ const linkPrefetchStrategy = function(url) {
       document.getElementsByName('script')[0].parentNode;
     parentElement.appendChild(link);
   });
-};
+}
 
-const xhrPrefetchStrategy = function(url) {
+function xhrPrefetchStrategy(url) {
   return new Promise((resolve, reject) => {
     const req = new XMLHttpRequest();
     req.open('GET', url, true);
@@ -57,7 +59,7 @@ const xhrPrefetchStrategy = function(url) {
 
     req.send(null);
   });
-};
+}
 
 const supportedPrefetchStrategy = support('prefetch')
   ? linkPrefetchStrategy
@@ -65,7 +67,7 @@ const supportedPrefetchStrategy = support('prefetch')
 
 const preFetched = {};
 
-const prefetch = function(url) {
+function prefetch(url) {
   return new Promise(resolve => {
     if (preFetched[url]) {
       resolve();
@@ -77,8 +79,8 @@ const prefetch = function(url) {
         resolve();
         preFetched[url] = true;
       })
-      .catch(() => {}); // 404s are logged to the console anyway
+      .catch(() => {}); // 404s are logged to the console anyway.
   });
-};
+}
 
 export default prefetch;
diff --git a/packages/docusaurus/src/client/preload.js b/packages/docusaurus/src/client/preload.js
index dd625f295f0b..e2ee5a5028e3 100644
--- a/packages/docusaurus/src/client/preload.js
+++ b/packages/docusaurus/src/client/preload.js
@@ -8,8 +8,8 @@
 import {matchRoutes} from 'react-router-config';
 
 /**
- * Helper function to make sure all async component for that particular route
- * is preloaded before rendering. This is especially useful to avoid loading screens
+ * Helper function to make sure all async components for that particular route
+ * is preloaded before rendering. This is especially useful to avoid loading screens.
  *
  * @param {Array<RouteConfig>} routes react-router-config
  * @param {string} pathname the route pathname, example: /docs/installation
@@ -17,12 +17,15 @@ import {matchRoutes} from 'react-router-config';
  */
 export default function preload(routes, pathname) {
   const matches = matchRoutes(routes, pathname);
+
   return Promise.all(
     matches.map(match => {
       const {component} = match.route;
+
       if (component && component.preload) {
         return component.preload();
       }
+
       return undefined;
     }),
   );
diff --git a/packages/docusaurus/src/client/serverEntry.js b/packages/docusaurus/src/client/serverEntry.js
index f0cb10cd0b53..97d2170425b6 100644
--- a/packages/docusaurus/src/client/serverEntry.js
+++ b/packages/docusaurus/src/client/serverEntry.js
@@ -21,7 +21,7 @@ import preload from './preload';
 import App from './App';
 import ssrTemplate from './templates/ssr.html.template';
 
-// Renderer for static-site-generator-webpack-plugin (async rendering via promises)
+// Renderer for static-site-generator-webpack-plugin (async rendering via promises).
 export default async function render(locals) {
   const {routesLocation, headTags, preBodyTags, postBodyTags} = locals;
   const location = routesLocation[locals.path];
@@ -50,7 +50,8 @@ export default async function render(locals) {
   const manifestPath = path.join(generatedFilesDir, 'client-manifest.json');
   const manifest = JSON.parse(await fs.readFile(manifestPath, 'utf8'));
 
-  // Get all required assets for this particular page based on client manifest information
+  // Get all required assets for this particular page based on client
+  // manifest information.
   const modulesToBeLoaded = [...manifest.entrypoints, ...Array.from(modules)];
   const bundles = getBundles(manifest, modulesToBeLoaded);
   const stylesheets = (bundles.css || []).map(b => b.file);
@@ -76,7 +77,7 @@ export default async function render(locals) {
     },
   );
 
-  // minify html with https://github.com/DanielRuf/html-minifier-terser
+  // Minify html with https://github.com/DanielRuf/html-minifier-terser
   return minify(renderedHtml, {
     removeComments: true,
     removeRedundantAttributes: true,
diff --git a/packages/docusaurus/src/commands/build.ts b/packages/docusaurus/src/commands/build.ts
index adaf0fdd08fe..d6b6d23ae99c 100644
--- a/packages/docusaurus/src/commands/build.ts
+++ b/packages/docusaurus/src/commands/build.ts
@@ -67,7 +67,7 @@ export async function build(
       new CleanWebpackPlugin({verbose: false}),
       // Visualize size of webpack output files with an interactive zoomable treemap.
       cliOptions.bundleAnalyzer && new BundleAnalyzerPlugin(),
-      // Generate client manifests file that will be used for server bundle
+      // Generate client manifests file that will be used for server bundle.
       new ReactLoadableSSRAddon({
         filename: clientManifestPath,
       }),
@@ -90,17 +90,19 @@ export async function build(
     });
   }
 
-  // Plugin lifecycle - configureWebpack
+  // Plugin Lifecycle - configureWebpack.
   plugins.forEach(plugin => {
     const {configureWebpack} = plugin;
     if (!configureWebpack) {
       return;
     }
+
     clientConfig = applyConfigureWebpack(
       configureWebpack.bind(plugin), // The plugin lifecycle may reference `this`.
       clientConfig,
       false,
     );
+
     serverConfig = applyConfigureWebpack(
       configureWebpack.bind(plugin), // The plugin lifecycle may reference `this`.
       serverConfig,
@@ -108,7 +110,8 @@ export async function build(
     );
   });
 
-  // Make sure generated client-manifest is cleaned first so we don't reuse the one from prevs build
+  // Make sure generated client-manifest is cleaned first so we don't reuse
+  // the one from previous builds.
   if (fs.existsSync(clientManifestPath)) {
     fs.unlinkSync(clientManifestPath);
   }
@@ -116,7 +119,7 @@ export async function build(
   // Run webpack to build JS bundle (client) and static html files (server).
   await compile([clientConfig, serverConfig]);
 
-  // Remove server.bundle.js because it is useless
+  // Remove server.bundle.js because it is not needed.
   if (
     serverConfig.output &&
     serverConfig.output.filename &&
@@ -128,7 +131,7 @@ export async function build(
     });
   }
 
-  /* Plugin lifecycle - postBuild */
+  // Plugin Lifecycle - postBuild.
   await Promise.all(
     plugins.map(async plugin => {
       if (!plugin.postBuild) {
diff --git a/packages/docusaurus/src/commands/deploy.ts b/packages/docusaurus/src/commands/deploy.ts
index 57f0a5cd6f25..222cc7c9c4e1 100644
--- a/packages/docusaurus/src/commands/deploy.ts
+++ b/packages/docusaurus/src/commands/deploy.ts
@@ -27,7 +27,7 @@ export async function deploy(siteDir: string): Promise<void> {
     throw new Error(`Please set the GIT_USER`);
   }
 
-  // The branch that contains the latest docs changes that will be deployed
+  // The branch that contains the latest docs changes that will be deployed.
   const currentBranch =
     process.env.CURRENT_BRANCH ||
     shell.exec('git rev-parse --abbrev-ref HEAD').stdout.trim();
@@ -52,7 +52,7 @@ export async function deploy(siteDir: string): Promise<void> {
     );
   }
 
-  // We never deploy on pull request
+  // We never deploy on pull request.
   const isPullRequest =
     process.env.CI_PULL_REQUEST || process.env.CIRCLE_PULL_REQUEST;
   if (isPullRequest) {
@@ -72,7 +72,7 @@ export async function deploy(siteDir: string): Promise<void> {
       ? `git@${githubHost}:${organizationName}/${projectName}.git`
       : `https://${gitUser}@${githubHost}/${organizationName}/${projectName}.git`;
 
-  // Check if this is a cross-repo publish
+  // Check if this is a cross-repo publish.
   const currentRepoUrl = shell
     .exec('git config --get remote.origin.url')
     .stdout.trim();
@@ -80,21 +80,22 @@ export async function deploy(siteDir: string): Promise<void> {
     `${organizationName}/${projectName}.git`,
   );
 
-  // We don't allow deploying to the same branch unless it's a cross publish
+  // We don't allow deploying to the same branch unless it's a cross publish.
   if (currentBranch === deploymentBranch && !crossRepoPublish) {
     throw new Error(
       `Cannot deploy from a ${deploymentBranch} branch. Only to it`,
     );
   }
 
-  // Save the commit hash that triggers publish-gh-pages before checking out to deployment branch
+  // Save the commit hash that triggers publish-gh-pages before checking
+  // out to deployment branch.
   const currentCommit = shell.exec('git rev-parse HEAD').stdout.trim();
 
-  // Clear docusaurus 2 cache dir for deploy consistency
+  // Clear Docusaurus 2 cache dir for deploy consistency.
   const tempDir = path.join(siteDir, '.docusaurus');
   fs.removeSync(tempDir);
 
-  // build static html files, then push to deploymentBranch branch of specified repo
+  // Build static html files, then push to deploymentBranch branch of specified repo.
   build(siteDir)
     .then(() => {
       shell.cd(tempDir);
@@ -109,8 +110,9 @@ export async function deploy(siteDir: string): Promise<void> {
 
       shell.cd(`${projectName}-${deploymentBranch}`);
 
-      // If the default branch is the one we're deploying to, then we'll fail to create it.
-      // This is the case of a cross-repo publish, where we clone a github.io repo with a default master branch.
+      // If the default branch is the one we're deploying to, then we'll fail
+      // to create it. This is the case of a cross-repo publish, where we clone
+      // a github.io repo with a default master branch.
       const defaultBranch = shell
         .exec('git rev-parse --abbrev-ref HEAD')
         .stdout.trim();
@@ -164,8 +166,10 @@ export async function deploy(siteDir: string): Promise<void> {
           // The commit might return a non-zero value when site is up to date.
           const websiteURL =
             githubHost === 'github.com'
-              ? `https://${organizationName}.github.io/${projectName}` // gh-pages hosted repo
-              : `https://${githubHost}/pages/${organizationName}/${projectName}`; // GitHub enterprise hosting.
+              ? // gh-pages hosted repo
+                `https://${organizationName}.github.io/${projectName}`
+              : // GitHub enterprise hosting.
+                `https://${githubHost}/pages/${organizationName}/${projectName}`;
           shell.echo(`Website is live at: ${websiteURL}`);
           shell.exit(0);
         }
diff --git a/packages/docusaurus/src/commands/external.ts b/packages/docusaurus/src/commands/external.ts
index 7a860bd176bc..63c93b3ae0b3 100644
--- a/packages/docusaurus/src/commands/external.ts
+++ b/packages/docusaurus/src/commands/external.ts
@@ -14,12 +14,14 @@ export function externalCommand(cli: CommanderStatic, siteDir: string): void {
   const pluginConfigs = loadPluginConfigs(context);
   const plugins = initPlugins({pluginConfigs, context});
 
-  // Plugin lifecycle - extendCli
+  // Plugin Lifecycle - extendCli.
   plugins.forEach(plugin => {
     const {extendCli} = plugin;
+
     if (!extendCli) {
       return;
     }
+
     extendCli(cli);
   });
 }
diff --git a/packages/docusaurus/src/commands/start.ts b/packages/docusaurus/src/commands/start.ts
index 6cb989d715e5..e26f21e95a65 100644
--- a/packages/docusaurus/src/commands/start.ts
+++ b/packages/docusaurus/src/commands/start.ts
@@ -92,7 +92,7 @@ export async function start(
           __dirname,
           '../client/templates/index.html.template.ejs',
         ),
-        // so we can define the position where the scripts are injected
+        // So we can define the position where the scripts are injected.
         inject: false,
         filename: 'index.html',
         title: siteConfig.title,
@@ -100,12 +100,12 @@ export async function start(
         preBodyTags,
         postBodyTags,
       }),
-      // This is necessary to emit hot updates for webpack-dev-server
+      // This is necessary to emit hot updates for webpack-dev-server.
       new HotModuleReplacementPlugin(),
     ],
   });
 
-  // Plugin lifecycle - configureWebpack
+  // Plugin Lifecycle - configureWebpack.
   plugins.forEach(plugin => {
     const {configureWebpack} = plugin;
     if (!configureWebpack) {
@@ -137,13 +137,13 @@ export async function start(
       rewrites: [{from: /\/*/, to: baseUrl}],
     },
     disableHostCheck: true,
-    // Disable overlay on browser since we use CRA's overlay error reporting
+    // Disable overlay on browser since we use CRA's overlay error reporting.
     overlay: false,
     host,
     before: (app, server) => {
       app.use(baseUrl, express.static(path.resolve(siteDir, STATIC_DIR_NAME)));
 
-      // This lets us fetch source contents from webpack for the error overlay
+      // This lets us fetch source contents from webpack for the error overlay.
       app.use(evalSourceMapMiddleware(server));
       // This lets us open files from the runtime error overlay.
       app.use(errorOverlayMiddleware());
diff --git a/packages/docusaurus/src/commands/swizzle.ts b/packages/docusaurus/src/commands/swizzle.ts
index 935bd994c33f..952d614b64bf 100644
--- a/packages/docusaurus/src/commands/swizzle.ts
+++ b/packages/docusaurus/src/commands/swizzle.ts
@@ -29,7 +29,7 @@ export async function swizzle(
       fromPath = path.join(fromPath, componentName);
       toPath = path.join(toPath, componentName);
 
-      // Handle single js file only.
+      // Handle single JavaScript file only.
       // E.g: if <fromPath> does not exist, we try to swizzle <fromPath>.js instead
       if (!fs.existsSync(fromPath) && fs.existsSync(`${fromPath}.js`)) {
         [fromPath, toPath] = [`${fromPath}.js`, `${toPath}.js`];
diff --git a/packages/docusaurus/src/server/config.ts b/packages/docusaurus/src/server/config.ts
index c8f1cdf7bbfb..2b2d4d5215ca 100644
--- a/packages/docusaurus/src/server/config.ts
+++ b/packages/docusaurus/src/server/config.ts
@@ -53,10 +53,12 @@ export function loadConfig(siteDir: string): DocusaurusConfig {
   if (!fs.existsSync(configPath)) {
     throw new Error(`${CONFIG_FILE_NAME} not found`);
   }
+
   const loadedConfig = importFresh(configPath) as Partial<DocusaurusConfig>;
   const missingFields = REQUIRED_FIELDS.filter(
     field => !_.has(loadedConfig, field),
   );
+
   if (missingFields.length > 0) {
     throw new Error(
       `The required field(s) ${formatFields(
@@ -76,6 +78,7 @@ export function loadConfig(siteDir: string): DocusaurusConfig {
   const unrecognizedFields = Object.keys(config).filter(
     field => !allowedFields.includes(field),
   );
+
   if (unrecognizedFields && unrecognizedFields.length > 0) {
     throw new Error(
       `The field(s) ${formatFields(
diff --git a/packages/docusaurus/src/server/html-tags/index.ts b/packages/docusaurus/src/server/html-tags/index.ts
index e2eb48dbe1d5..7b08bbe924b7 100644
--- a/packages/docusaurus/src/server/html-tags/index.ts
+++ b/packages/docusaurus/src/server/html-tags/index.ts
@@ -44,6 +44,7 @@ export function loadHtmlTags(plugins: Plugin<any>[]): InjectedHtmlTags {
     },
     {headTags: '', preBodyTags: '', postBodyTags: ''},
   );
+
   return {
     headTags: htmlTags.headTags.trim(),
     preBodyTags: htmlTags.preBodyTags.trim(),
diff --git a/packages/docusaurus/src/server/index.ts b/packages/docusaurus/src/server/index.ts
index f140e88b6403..829029f4d1f9 100644
--- a/packages/docusaurus/src/server/index.ts
+++ b/packages/docusaurus/src/server/index.ts
@@ -52,14 +52,14 @@ export function loadPluginConfigs(context: LoadContext): PluginConfig[] {
   return [
     ...presetPlugins,
     ...presetThemes,
-    // Site config should the highest priority.
+    // Site config should be the highest priority.
     ...(siteConfig.plugins || []),
     ...(siteConfig.themes || []),
   ];
 }
 
 export async function load(siteDir: string): Promise<Props> {
-  // Context
+  // Context.
   const context: LoadContext = loadContext(siteDir);
   const {generatedFilesDir, siteConfig, outDir, baseUrl} = context;
   const genSiteConfig = generate(
@@ -68,7 +68,7 @@ export async function load(siteDir: string): Promise<Props> {
     `export default ${JSON.stringify(siteConfig, null, 2)};`,
   );
 
-  // Plugins
+  // Plugins.
   const pluginConfigs: PluginConfig[] = loadPluginConfigs(context);
   const {plugins, pluginsRouteConfigs} = await loadPlugins({
     pluginConfigs,
@@ -83,7 +83,9 @@ export async function load(siteDir: string): Promise<Props> {
   const userTheme = path.resolve(siteDir, THEME_PATH);
   const alias = loadThemeAlias([fallbackTheme, ...pluginThemes, userTheme]);
 
-  // Make a fake plugin to resolve aliased theme components && inject scripts/stylesheets
+  // Make a fake plugin to:
+  // - Resolve aliased theme components
+  // - Inject scripts/stylesheets
   const {stylesheets = [], scripts = []} = siteConfig;
   plugins.push({
     name: 'docusaurus-bootstrap-plugin',
@@ -134,10 +136,10 @@ export async function load(siteDir: string): Promise<Props> {
       .join('\n')}\n];\n`,
   );
 
-  // Load extra head & body html tags
+  // Load extra head & body html tags.
   const {headTags, preBodyTags, postBodyTags} = loadHtmlTags(plugins);
 
-  // Routing
+  // Routing.
   const {
     registry,
     routesChunkNames,
diff --git a/packages/docusaurus/src/server/loadSetup.ts b/packages/docusaurus/src/server/loadSetup.ts
index f148c0c9c235..c4baeab7c69b 100644
--- a/packages/docusaurus/src/server/loadSetup.ts
+++ b/packages/docusaurus/src/server/loadSetup.ts
@@ -9,7 +9,7 @@ import path from 'path';
 import {load} from './index';
 import {Props} from '@docusaurus/types';
 
-// Helper methods to setup dummy/fake projects
+// Helper methods to setup dummy/fake projects.
 export const loadSetup = async (name: string): Promise<Props> => {
   const fixtures = path.join(__dirname, '__tests__', '__fixtures__');
   const simpleSite = path.join(fixtures, 'simple-site');
diff --git a/packages/docusaurus/src/server/plugins/index.ts b/packages/docusaurus/src/server/plugins/index.ts
index 6e43091fdc50..01383fd15fd5 100644
--- a/packages/docusaurus/src/server/plugins/index.ts
+++ b/packages/docusaurus/src/server/plugins/index.ts
@@ -18,7 +18,8 @@ import {
 import {initPlugins} from './init';
 
 export function sortConfig(routeConfigs: RouteConfig[]) {
-  // Sort the route config. This ensures that route with nested routes is always placed last
+  // Sort the route config. This ensures that route with nested
+  // routes is always placed last.
   routeConfigs.sort((a, b) => {
     if (a.routes && !b.routes) {
       return 1;
@@ -26,15 +27,17 @@ export function sortConfig(routeConfigs: RouteConfig[]) {
     if (!a.routes && b.routes) {
       return -1;
     }
-    // Higher priority get placed first
+    // Higher priority get placed first.
     if (a.priority || b.priority) {
       const priorityA = a.priority || 0;
       const priorityB = b.priority || 0;
       const score = priorityA > priorityB ? -1 : priorityB > priorityA ? 1 : 0;
+
       if (score !== 0) {
         return score;
       }
     }
+
     return a.path > b.path ? 1 : b.path > a.path ? -1 : 0;
   });
 }
@@ -49,24 +52,24 @@ export async function loadPlugins({
   plugins: Plugin<any>[];
   pluginsRouteConfigs: RouteConfig[];
 }> {
-  // 1. Plugin Lifecycle - Initialization/Constructor
+  // 1. Plugin Lifecycle - Initialization/Constructor.
   const plugins: Plugin<any>[] = initPlugins({pluginConfigs, context});
 
-  // 2. Plugin lifecycle - loadContent
-  // Currently plugins run lifecycle in parallel and are not order-dependent. We could change
-  // this in future if there are plugins which need to run in certain order or depend on
-  // others for data.
+  // 2. Plugin Lifecycle - loadContent.
+  // Currently plugins run lifecycle methods in parallel and are not order-dependent.
+  // We could change this in future if there are plugins which need to
+  // run in certain order or depend on others for data.
   const pluginsLoadedContent = await Promise.all(
     plugins.map(async plugin => {
       if (!plugin.loadContent) {
         return null;
       }
-      const content = await plugin.loadContent();
-      return content;
+
+      return await plugin.loadContent();
     }),
   );
 
-  // 3. Plugin lifecycle - contentLoaded
+  // 3. Plugin Lifecycle - contentLoaded.
   const pluginsRouteConfigs: RouteConfig[] = [];
 
   await Promise.all(
@@ -97,7 +100,8 @@ export async function loadPlugins({
     }),
   );
 
-  // Sort the route config. This ensures that route with nested routes is always placed last
+  // Sort the route config. This ensures that route with nested
+  // routes are always placed last.
   sortConfig(pluginsRouteConfigs);
 
   return {
diff --git a/packages/docusaurus/src/server/plugins/init.ts b/packages/docusaurus/src/server/plugins/init.ts
index e176958fa636..86ac21bf6ecb 100644
--- a/packages/docusaurus/src/server/plugins/init.ts
+++ b/packages/docusaurus/src/server/plugins/init.ts
@@ -20,6 +20,7 @@ export function initPlugins({
     pluginConfigs.map(pluginItem => {
       let pluginModuleImport;
       let pluginOptions = {};
+
       if (!pluginItem) {
         return null;
       }
@@ -35,7 +36,8 @@ export function initPlugins({
         return null;
       }
 
-      // module is any valid module identifier - npm package or locally-resolved path.
+      // The pluginModuleImport value is any valid
+      // module identifier - npm package or locally-resolved path.
       const pluginModule: any = importFresh(pluginModuleImport);
       return (pluginModule.default || pluginModule)(context, pluginOptions);
     }),
diff --git a/packages/docusaurus/src/server/routes.ts b/packages/docusaurus/src/server/routes.ts
index ad9f8f27343a..c827597b6108 100644
--- a/packages/docusaurus/src/server/routes.ts
+++ b/packages/docusaurus/src/server/routes.ts
@@ -54,7 +54,7 @@ export async function loadRoutes(
     [routePath: string]: ChunkNames;
   } = {};
 
-  // This is the higher level overview of route code generation
+  // This is the higher level overview of route code generation.
   function generateRouteCode(routeConfig: RouteConfig): string {
     const {
       path: routePath,
@@ -94,7 +94,7 @@ export async function loadRoutes(
       if (isModule(value)) {
         const modulePath = getModulePath(value);
         const chunkName = genChunkName(modulePath, prefix, name);
-        // We need to JSON.stringify so that if its on windows, backslash are escaped.
+        // We need to JSON.stringify so that if its on windows, backslashes are escaped.
         const loader = `() => import(/* webpackChunkName: '${chunkName}' */ ${JSON.stringify(
           modulePath,
         )})`;