[Init] Initial commit - NetMesh terminal manager

components/ai-elements/streamdownCodeHighlighter.ts

@@ -0,0 +1,77 @@
+import type {
+  CodeHighlighterPlugin,
+  HighlightOptions,
+} from 'streamdown';
+import type { BundledLanguage } from 'shiki';
+
+type HighlightResult = NonNullable<ReturnType<CodeHighlighterPlugin['highlight']>>;
+
+const PLAIN_TEXT_LANGUAGES = new Set([
+  '',
+  'plain',
+  'plaintext',
+  'text',
+  'txt',
+]);
+
+const LANGUAGE_ALIASES: Record<string, BundledLanguage> = {
+  cfg: 'ini',
+  conf: 'ini',
+  config: 'ini',
+};
+
+export const createPlainCodeHighlightResult = (source: string): HighlightResult => {
+  const code = source.replace(/\n+$/, '');
+  return {
+    bg: 'transparent',
+    fg: 'inherit',
+    tokens: code.split('\n').map((line) => [
+      {
+        content: line,
+        color: 'inherit',
+        bgColor: 'transparent',
+        htmlStyle: {},
+        offset: 0,
+      },
+    ]),
+  };
+};
+
+const normalizeLanguageKey = (language: string): string =>
+  language.trim().toLowerCase();
+
+export const resolveSupportedCodeLanguage = (
+  highlighter: CodeHighlighterPlugin,
+  language: string,
+): BundledLanguage | null => {
+  const key = normalizeLanguageKey(language);
+  if (PLAIN_TEXT_LANGUAGES.has(key)) return null;
+
+  const direct = key as BundledLanguage;
+  if (highlighter.supportsLanguage(direct)) return direct;
+
+  const alias = LANGUAGE_ALIASES[key];
+  if (alias && highlighter.supportsLanguage(alias)) return alias;
+
+  return null;
+};
+
+export const createSafeCodeHighlighter = (
+  highlighter: CodeHighlighterPlugin,
+): CodeHighlighterPlugin => ({
+  ...highlighter,
+  supportsLanguage(language) {
+    return resolveSupportedCodeLanguage(highlighter, language) !== null;
+  },
+  highlight(options: HighlightOptions, callback?: (result: HighlightResult) => void) {
+    const supportedLanguage = resolveSupportedCodeLanguage(highlighter, options.language);
+    if (!supportedLanguage) {
+      return createPlainCodeHighlightResult(options.code);
+    }
+
+    return highlighter.highlight(
+      { ...options, language: supportedLanguage },
+      callback,
+    );
+  },
+});