feat(content-blog): new readingTime plugin option (#5702)

packages/docusaurus-plugin-content-blog/src/__tests__/feed.test.ts

@@ -77,6 +77,8 @@ describe('blogFeed', () => {
               type: [feedType],
               copyright: 'Copyright',
             },
+            readingTime: ({content, defaultReadingTime}) =>
+              defaultReadingTime({content}),
           } as PluginOptions,
         );
 
@@ -111,6 +113,8 @@ describe('blogFeed', () => {
               type: [feedType],
               copyright: 'Copyright',
             },
+            readingTime: ({content, defaultReadingTime}) =>
+              defaultReadingTime({content}),
           } as PluginOptions,
         );
         const feedContent =

packages/docusaurus-plugin-content-blog/src/blogUtils.ts

@@ -16,6 +16,7 @@ import {
   BlogContentPaths,
   BlogMarkdownLoaderOptions,
   BlogTags,
+  ReadingTimeFunction,
 } from './types';
 import {
   parseMarkdownFile,
@@ -111,6 +112,10 @@ async function parseBlogPostMarkdownFile(blogSourceAbsolute: string) {
   };
 }
 
+const defaultReadingTime: ReadingTimeFunction = ({content, options}) => {
+  return readingTime(content, options).minutes;
+};
+
 async function processBlogSourceFile(
   blogSourceRelative: string,
   contentPaths: BlogContentPaths,
@@ -227,7 +232,13 @@ async function processBlogSourceFile(
       date,
       formattedDate,
       tags: normalizeFrontMatterTags(tagsBasePath, frontMatter.tags),
-      readingTime: showReadingTime ? readingTime(content).minutes : undefined,
+      readingTime: showReadingTime
+        ? options.readingTime({
+            content,
+            frontMatter,
+            defaultReadingTime,
+          })
+        : undefined,
       truncated: truncateMarker?.test(content) || false,
       authors,
     },

packages/docusaurus-plugin-content-blog/src/pluginOptionSchema.ts

@@ -41,6 +41,7 @@ export const DEFAULT_OPTIONS: PluginOptions = {
   path: 'blog',
   editLocalizedFiles: false,
   authorsMapPath: 'authors.yml',
+  readingTime: ({content, defaultReadingTime}) => defaultReadingTime({content}),
 };
 
 export const PluginOptionSchema = Joi.object<PluginOptions>({
@@ -113,4 +114,5 @@ export const PluginOptionSchema = Joi.object<PluginOptions>({
     language: Joi.string(),
   }).default(DEFAULT_OPTIONS.feedOptions),
   authorsMapPath: Joi.string().default(DEFAULT_OPTIONS.authorsMapPath),
+  readingTime: Joi.function().default(() => DEFAULT_OPTIONS.readingTime),
 });

packages/docusaurus-plugin-content-blog/src/types.ts

@@ -12,6 +12,7 @@ import type {
   ContentPaths,
 } from '@docusaurus/utils/lib/markdownLinks';
 import {Overwrite} from 'utility-types';
+import {BlogPostFrontMatter} from './blogFrontMatter';
 
 export type BlogContentPaths = ContentPaths;
 
@@ -46,6 +47,24 @@ export type EditUrlFunction = (editUrlParams: {
   locale: string;
 }) => string | undefined;
 
+// Duplicate from ngryman/reading-time to keep stability of API
+type ReadingTimeOptions = {
+  wordsPerMinute?: number;
+  wordBound?: (char: string) => boolean;
+};
+
+export type ReadingTimeFunction = (params: {
+  content: string;
+  frontMatter?: BlogPostFrontMatter & Record<string, unknown>;
+  options?: ReadingTimeOptions;
+}) => number;
+
+export type ReadingTimeFunctionOption = (
+  params: Required<Omit<Parameters<ReadingTimeFunction>[0], 'options'>> & {
+    defaultReadingTime: ReadingTimeFunction;
+  },
+) => number | undefined;
+
 export type PluginOptions = RemarkAndRehypePluginOptions & {
   id?: string;
   path: string;
@@ -76,6 +95,7 @@ export type PluginOptions = RemarkAndRehypePluginOptions & {
   editLocalizedFiles?: boolean;
   admonitions: Record<string, unknown>;
   authorsMapPath: string;
+  readingTime: ReadingTimeFunctionOption;
 };
 
 // Options, as provided in the user config (before normalization)