feat: add estimated reading time to articles

docusaurus.config.js

@@ -3,6 +3,7 @@ import { themes as prismThemes } from "prism-react-renderer";
 
 const remarkMath = require("remark-math");
 const rehypeKatex = require("rehype-katex");
+const readingTimePlugin = require("./plugins/remark-reading-time");
 
 const path = require("path");
 
@@ -56,7 +57,7 @@ const config = {
           },
           editUrl:
             "https://github.com/codeharborhub/codeharborhub.github.io/edit/main/",
-          remarkPlugins: [remarkMath],
+          remarkPlugins: [readingTimePlugin, remarkMath],
           rehypePlugins: [rehypeKatex],
         },
         pages: {

plugins/remark-reading-time.js

@@ -0,0 +1,46 @@
+/**
+ * Remark plugin to calculate and inject reading time into frontmatter
+ * Estimates reading time based on word count (average 200 words per minute)
+ * Code blocks are weighted at 0.5x since code is read differently than prose
+ */
+
+const { visit } = require('unist-util-visit');
+
+module.exports = function readingTimePlugin() {
+  return (tree, vfile) => {
+    let wordCount = 0;
+    let codeWordCount = 0;
+
+    // Count words in text nodes
+    visit(tree, 'text', (node) => {
+      wordCount += node.value
+        .split(/\s+/)
+        .filter((word) => word.length > 0).length;
+    });
+
+    // Count words in code blocks (weighted at 0.5x)
+    visit(tree, 'code', (node) => {
+      codeWordCount += node.value
+        .split(/\s+/)
+        .filter((word) => word.length > 0).length;
+    });
+
+    visit(tree, 'inlineCode', (node) => {
+      codeWordCount += node.value
+        .split(/\s+/)
+        .filter((word) => word.length > 0).length;
+    });
+
+    // Calculate total words with code weighted at 0.5x
+    const totalWords = wordCount + codeWordCount * 0.5;
+
+    // Estimate reading time (200 words per minute, minimum 1 minute)
+    const readingTime = Math.max(1, Math.round(totalWords / 200));
+
+    // Inject into frontmatter
+    if (!vfile.data.frontMatter) {
+      vfile.data.frontMatter = {};
+    }
+    vfile.data.frontMatter.readingTime = readingTime;
+  };
+};