✨Add stdlib to house commond PlatformScript modules

We need a way to have shared, common modules for PlatformScript.

This will mount eveything that is in `/stdlib` at
`https://pls.pub/std`

The `version` parameter is captured in the route because eventually we
will want to use pinned versions of the standard library. However, for
now, this will always use the specific version at the version of the
website.

Author: cowboyd

stdlib/examples/welcome.yaml

@@ -0,0 +1 @@
+Welcome to PlatformScript!

www/deno.lock

@@ -12,7 +12,8 @@ import * as $5 from "./routes/gfm.css.ts";
 import * as $6 from "./routes/index.tsx";
 import * as $7 from "./routes/playground.tsx";
 import * as $8 from "./routes/pls.tsx";
-import * as $9 from "./routes/worker.js.ts";
+import * as $9 from "./routes/std.tsx";
+import * as $10 from "./routes/worker.js.ts";
 import * as $$0 from "./islands/CopyArea.tsx";
 import * as $$1 from "./islands/ps-playground.tsx";
 
@@ -27,7 +28,8 @@ const manifest = {
     "./routes/index.tsx": $6,
     "./routes/playground.tsx": $7,
     "./routes/pls.tsx": $8,
-    "./routes/worker.js.ts": $9,
+    "./routes/std.tsx": $9,
+    "./routes/worker.js.ts": $10,
   },
   islands: {
     "./islands/CopyArea.tsx": $$0,

www/fresh.gen.ts

@@ -0,0 +1,12 @@
+import { Handlers, RouteConfig } from "$fresh/server.ts";
+import { serveFile } from "https://deno.land/std@0.176.0/http/file_server.ts";
+
+export const handler: Handlers<unknown> = {
+  async GET(req, cxt) {
+    let { params: { path } } = cxt;
+    let location = new URL(`../../stdlib/${path}`, import.meta.url);
+    return await serveFile(req, location.pathname);
+  },
+};
+
+export const config: RouteConfig = { routeOverride: "/std{@:version}?/:path*" };

www/routes/std.tsx

@@ -59,4 +59,20 @@ describe("www", () => {
       `<base href="http://example.com/path/to/subdir/" />`,
     );
   });
+
+  it("can retrieve things from the standard library", async () => {
+    let response = await fetch(
+      "http://localhost:9999/std/examples/welcome.yaml",
+    );
+    let content = await response.text();
+    expect(response.headers.get("Content-Type")).toContain("text/yaml");
+    expect(content).toContain("Welcome to PlatformScript!");
+  });
+
+  it("will not find things outside the 'libstd' directory`", async () => {
+    let response = await fetch("http://localhost:9999/std/.../README.md");
+    let text = await response.text();
+    expect(response.status).toEqual(404);
+    expect(text).toContain("Not Found");
+  });
 });