feature: support more than html for SSI

handlers/html.ts

@@ -4,6 +4,7 @@
  */
 
 import * as path from '@std/path';
+import { md_to_html } from '@andyburke/serverus/handlers/markdown';
 
 // https://stackoverflow.com/a/75205316
 const replaceAsync = async (str: string, regex: RegExp, asyncFn: (match: any, ...args: any) => Promise<any>) => {
@@ -34,7 +35,27 @@ async function load_html_with_ssi(html_file: string): Promise<string> {
 						break;
 					}
 
-					return await load_html_with_ssi(resolved);
+					const HANDLERS: Record<string, (include_path: string) => Promise<string> | string> = {
+						default: async (include_path: string) => {
+							try {
+								return await Deno.readTextFile(include_path);
+							} catch (error) {
+								console.dir({ error });
+								throw error;
+							}
+						},
+
+						'.md': async (include_path: string) => {
+							const markdown_content = await Deno.readTextFile(include_path);
+							return md_to_html(markdown_content);
+						},
+
+						'.html': load_html_with_ssi
+					};
+
+					const extension = path.extname(resolved);
+					const handler = extension ? (HANDLERS[extension.toLowerCase()] ?? HANDLERS.default) : HANDLERS.default;
+					return await handler(resolved);
 				}
 
 				default: {