feat: serving static files (#59)

Co-authored-by: Yoshiya Hinosawa <stibium121@gmail.com>

data/http-server-files.ts

@@ -0,0 +1,44 @@
+/**
+ * @title HTTP Server: Serving Files
+ * @difficulty intermediate
+ * @tags cli, deploy
+ * @run --allow-net --allow-read <url>
+ * @resource {$std/http/mod.ts} Doc: std/http
+ * @resource {/http-server} Example: HTTP Server: Hello World
+ *
+ * An example of a HTTP server that serves files.
+ */
+
+// Import utility methods for serving files with mime types.
+import { serveDir, serveFile } from "$std/http/file_server.ts";
+
+// Import the http server from std/http.
+import { serve } from "$std/http/server.ts";
+
+// Here we start a simple server
+serve((req: Request) => {
+  // Get the path from the url (ie. example.com/whatever -> /whatever)
+  const pathname = new URL(req.url).pathname;
+
+  if (pathname === "/simple_file") {
+    // In the most basic case we can just call this function with the
+    // request object and path to the file
+    return serveFile(req, "./path/to/file.txt");
+  }
+
+  if (pathname.startsWith("/static")) {
+    // We can also serve a whole directory using the serveDir utility
+    // method. By default it serves the current directory but this
+    // can be changed using the "fsRoot" option. We can use the "urlRoot"
+    // option to strip off the start of the url in the case we don't
+    // serve the directory at the top level.
+    return serveDir(req, {
+      fsRoot: "public",
+      urlRoot: "static",
+    });
+  }
+
+  return new Response("404: Not Found", {
+    status: 404,
+  });
+});

toc.js

@@ -35,6 +35,7 @@ export const TOC = [
   "http-server",
   "http-server-routing",
   "http-server-streaming",
+  "http-server-files",
   "tcp-listener",
   "tcp-connector",
 ];