feat: highlight code blocks

packages/app/package.json

@@ -19,6 +19,7 @@
     "debug": "^4.3.4",
     "dexie": "^3.2.4",
     "emojilib": "^3.0.10",
+    "highlight.js": "^11.8.0",
     "light-bolt11-decoder": "^2.1.0",
     "match-sorter": "^6.3.1",
     "qr-code-styling": "^1.6.0-rc.1",

packages/app/src/Element/CodeBlock.css

@@ -0,0 +1,14 @@
+.codeblock {
+  overflow: auto;
+  position: relative;
+}
+
+.codeblock pre {
+  overflow: auto;
+  line-height: 1.4;
+  font-size: var(--font-size);
+}
+
+.hljs {
+  background: #f6f8fa;
+}

packages/app/src/Element/CodeBlock.tsx

@@ -0,0 +1,24 @@
+import { useEffect } from "react";
+import "highlight.js/styles/github.css";
+import "./CodeBlock.css";
+
+const CodeBlock = ({ content, language }: { content: string; language?: string }) => {
+  useEffect(() => {
+    const importHljs = async () => {
+      const hljs = (await import("highlight.js")).default;
+      hljs.highlightAll();
+    };
+
+    importHljs();
+  });
+
+  return (
+    <div className={`codeblock ${language && `language-${language}`}`} dir="auto">
+      <pre>
+        <code className={language && `language-${language}`}>{content.trim()}</code>
+      </pre>
+    </div>
+  );
+};
+
+export default CodeBlock;

packages/app/src/Element/Text.tsx

@@ -11,6 +11,7 @@ import { ProxyImg } from "./ProxyImg";
 import { SpotlightMediaModal } from "./Deck/SpotlightMedia";
 import HighlightedText from "./HighlightedText";
 import { useTextTransformer } from "Hooks/useTextTransformCache";
+import CodeBlock from "./CodeBlock";
 
 export interface TextProps {
   id: string;
@@ -254,6 +255,9 @@ export default function Text({
       if (element.type === "custom_emoji") {
         chunks.push(<ProxyImg src={element.content} size={15} className="custom-emoji" />);
       }
+      if (element.type === "code_block") {
+        chunks.push(<CodeBlock content={element.content} language={element.language} />);
+      }
       if (element.type === "text") {
         chunks.push(
           <div className="text-frag">

packages/system/src/const.ts

@@ -34,3 +34,8 @@ export const CashuRegex = /(cashuA[A-Za-z0-9_-]{0,10000}={0,3})/i;
  * Regex to match any npub/nevent/naddr/nprofile/note
  */
 export const MentionNostrEntityRegex = /@n(pub|profile|event|ote|addr|)1[acdefghjklmnpqrstuvwxyz023456789]+/g;
+
+/**
+ * Regex to match markdown code content
+ */
+export const MarkdownCodeRegex = /(```.+?```)/gms;

packages/system/src/text.ts

@@ -1,13 +1,31 @@
 import { unwrap } from "@snort/shared";
 
-import { CashuRegex, FileExtensionRegex, HashtagRegex, InvoiceRegex, MentionNostrEntityRegex } from "./const";
+import {
+  CashuRegex,
+  FileExtensionRegex,
+  HashtagRegex,
+  InvoiceRegex,
+  MarkdownCodeRegex,
+  MentionNostrEntityRegex,
+} from "./const";
 import { validateNostrLink } from "./nostr-link";
 import { splitByUrl } from "./utils";
 
 export interface ParsedFragment {
-  type: "text" | "link" | "mention" | "invoice" | "media" | "cashu" | "hashtag" | "custom_emoji" | "highlighted_text";
+  type:
+    | "text"
+    | "link"
+    | "mention"
+    | "invoice"
+    | "media"
+    | "cashu"
+    | "hashtag"
+    | "custom_emoji"
+    | "highlighted_text"
+    | "code_block";
   content: string;
   mimeType?: string;
+  language?: string;
 }
 
 export type Fragment = string | ParsedFragment;
@@ -179,6 +197,31 @@ function extractCustomEmoji(fragments: Fragment[], tags: Array<Array<string>>) {
     .flat();
 }
 
+function extractMarkdownCode(fragments: Fragment[]): (string | ParsedFragment)[] {
+  return fragments
+    .map(f => {
+      if (typeof f === "string") {
+        return f.split(MarkdownCodeRegex).map(i => {
+          if (i.startsWith("```") && i.endsWith("```")) {
+            const firstLineBreakIndex = i.indexOf("\n");
+            const lastLineBreakIndex = i.lastIndexOf("\n");
+
+            return {
+              type: "code_block",
+              content: i.substring(firstLineBreakIndex, lastLineBreakIndex),
+              language: i.substring(3, firstLineBreakIndex),
+            } as ParsedFragment;
+          } else {
+            return i;
+          }
+        });
+      }
+
+      return f;
+    })
+    .flat();
+}
+
 export function transformText(body: string, tags: Array<Array<string>>) {
   let fragments = extractLinks([body]);
   fragments = extractMentions(fragments);
@@ -186,6 +229,7 @@ export function transformText(body: string, tags: Array<Array<string>>) {
   fragments = extractInvoices(fragments);
   fragments = extractCashuTokens(fragments);
   fragments = extractCustomEmoji(fragments, tags);
+  fragments = extractMarkdownCode(fragments);
   fragments = fragments
     .map(a => {
       if (typeof a === "string") {