Serve the shortlink service on Deno Deploy v2

README.md

@@ -102,24 +102,24 @@ The library runs in the browser via esm.sh — no build step required:
 
 ```html
 <script id="shortlinks" type="application/json">
-  {
-    "github": "https://github.com"
-  }
+{
+  "github": "https://github.com"
+}
 </script>
 <script type="importmap">
-  {
-    "imports": {
-      "@fartlabs/go": "https://esm.sh/jsr/@fartlabs/go@0.0.3"
-    }
+{
+  "imports": {
+    "@fartlabs/go": "https://esm.sh/jsr/@fartlabs/go@0.0.3"
   }
+}
 </script>
 <script type="module">
-  import { go } from "@fartlabs/go";
-  const shortlinks = JSON.parse(
-    document.getElementById("shortlinks").textContent,
-  );
-  const result = go(new URL(location.href), shortlinks);
-  // ...
+import { go } from "@fartlabs/go";
+const shortlinks = JSON.parse(
+  document.getElementById("shortlinks").textContent,
+);
+const result = go(new URL(location.href), shortlinks);
+// ...
 </script>
 ```
 

cli/main.tsx

@@ -20,23 +20,38 @@ type Shortlinks = Record<string, string>;
 
 class GoService {
   public constructor(
-    private readonly kv: Deno.Kv,
+    private readonly kv: Deno.Kv | undefined,
+    private readonly staticShortlinks: Shortlinks = {},
     private readonly kvNamespace: Deno.KvKey = ["go"],
   ) {}
 
+  public get writable(): boolean {
+    return this.kv !== undefined;
+  }
+
+  private requireKv(): Deno.Kv {
+    if (!this.kv) {
+      throw new Error(
+        "Shortlinks are read-only: no Deno KV database is bound to this deployment.",
+      );
+    }
+    return this.kv;
+  }
+
   public async add(
     alias: string,
     destination: string,
     force = false,
   ): Promise<void> {
-    const shortlinksResult = await this.kv.get<Shortlinks>(this.kvNamespace);
+    const kv = this.requireKv();
+    const shortlinksResult = await kv.get<Shortlinks>(this.kvNamespace);
     const shortlinks = shortlinksResult.value ?? {};
     if (!force && shortlinks[alias]) {
       throw new Error("Shortlink already exists.");
     }
 
     shortlinks[alias] = destination;
-    const result = await this.kv.atomic()
+    const result = await kv.atomic()
       .check(shortlinksResult)
       .set(this.kvNamespace, shortlinks)
       .commit();
@@ -46,14 +61,15 @@ class GoService {
   }
 
   public async delete(alias: string): Promise<void> {
-    const shortlinksResult = await this.kv.get<Shortlinks>(this.kvNamespace);
+    const kv = this.requireKv();
+    const shortlinksResult = await kv.get<Shortlinks>(this.kvNamespace);
     const shortlinks = shortlinksResult.value ?? {};
     if (!shortlinks[alias]) {
       throw new Error("Shortlink does not exist.");
     }
 
     delete shortlinks[alias];
-    const result = await this.kv.atomic()
+    const result = await kv.atomic()
       .check(shortlinksResult)
       .set(this.kvNamespace, shortlinks)
       .commit();
@@ -63,8 +79,11 @@ class GoService {
   }
 
   public async shortlinks(): Promise<Shortlinks> {
+    if (!this.kv) {
+      return this.staticShortlinks;
+    }
     const shortlinksResult = await this.kv.get<Shortlinks>(this.kvNamespace);
-    return shortlinksResult.value ?? {};
+    return { ...this.staticShortlinks, ...(shortlinksResult.value ?? {}) };
   }
 }
 
@@ -85,6 +104,15 @@ function GoRouter(props: { service: GoService }) {
           if (!isAuthorized(ctx.request.headers)) {
             return Response.json({ error: "Unauthorized" }, { status: 401 });
           }
+          if (!props.service.writable) {
+            return Response.json(
+              {
+                error:
+                  "Shortlinks are read-only: no Deno KV database is bound.",
+              },
+              { status: 503 },
+            );
+          }
 
           const body = await ctx.request.json();
           await props.service.add(body.alias, body.destination, body.force);
@@ -100,6 +128,15 @@ function GoRouter(props: { service: GoService }) {
           if (!isAuthorized(ctx.request.headers)) {
             return Response.json({ error: "Unauthorized" }, { status: 401 });
           }
+          if (!props.service.writable) {
+            return Response.json(
+              {
+                error:
+                  "Shortlinks are read-only: no Deno KV database is bound.",
+              },
+              { status: 503 },
+            );
+          }
 
           const body = await ctx.request.json();
           await props.service.delete(body.alias);
@@ -183,6 +220,12 @@ function GoRouter(props: { service: GoService }) {
           const shortlinks = await props.service.shortlinks();
           const url = new URL(ctx.request.url);
           const destination = go(url, shortlinks);
+          if (destination.href === url.href) {
+            return Response.json(
+              { error: `Shortlink not found: ${url.pathname}` },
+              { status: 404 },
+            );
+          }
           return new Response(
             null,
             {
@@ -196,9 +239,39 @@ function GoRouter(props: { service: GoService }) {
   );
 }
 
+const staticShortlinks: Shortlinks = JSON.parse(
+  Deno.readTextFileSync(new URL("../links.json", import.meta.url)),
+);
+
+async function openKvIfAvailable(): Promise<Deno.Kv | undefined> {
+  try {
+    return await Deno.openKv();
+  } catch (error) {
+    console.warn(
+      "Deno KV is unavailable, serving links.json read-only:",
+      String(error),
+    );
+    return undefined;
+  }
+}
+
+const kv = await openKvIfAvailable();
+
+let serviceRouter: ReturnType<typeof GoRouter> | undefined;
+
+function getServiceRouter(): ReturnType<typeof GoRouter> {
+  if (!serviceRouter) {
+    serviceRouter = <GoRouter service={new GoService(kv, staticShortlinks)} />;
+  }
+  return serviceRouter;
+}
+
+export default {
+  fetch: (request: Request) => getServiceRouter().fetch(request),
+} satisfies Deno.ServeDefaultExport;
+
 if (import.meta.main) {
-  const kv = await Deno.openKv();
-  const goService = new GoService(kv);
-  const router = <GoRouter service={goService} />;
-  Deno.serve((request) => router.fetch(request));
+  const port = parseInt(Deno.env.get("PORT") ?? "8000");
+  console.info(`go.fart.tools development server: http://localhost:${port}/`);
+  Deno.serve({ port }, (request) => getServiceRouter().fetch(request));
 }

demo/browser.html

@@ -4,54 +4,53 @@
     <meta charset="UTF-8" />
     <title>go — browser demo</title>
     <script type="importmap">
-      {
-        "imports": {
-          "@fartlabs/go": "https://esm.sh/jsr/@fartlabs/go@0.0.3"
-        }
+    {
+      "imports": {
+        "@fartlabs/go": "https://esm.sh/jsr/@fartlabs/go@0.0.3"
       }
+    }
     </script>
     <script id="shortlinks" type="application/json">
-      {
-        "github": "https://github.com",
-        "docs": "/documentation",
-        "docs/api": "/reference"
-      }
+    {
+      "github": "https://github.com",
+      "docs": "/documentation",
+      "docs/api": "/reference"
+    }
     </script>
   </head>
   <body>
     <script type="module">
-      import { go } from "@fartlabs/go";
-      const shortlinks = JSON.parse(
-        document.getElementById("shortlinks").textContent,
-      );
-      const url = new URL(window.location.href);
-      const result = go(url, shortlinks);
-      if (result.href !== url.href) {
-        // Redirect via meta-refresh
-        document.open();
-        document.write(`<!DOCTYPE html>
-<html>
-<head>
-  <meta http-equiv="refresh" content="0;url=${result.href}">
-  <title>Redirecting…</title>
-</head>
-<body>
-  <p>Resolving <code>${url.href}</code> → <a href="${result.href}">${result.href}</a></p>
-</body>
-</html>`);
-        document.close();
-      } else {
-        // Render shortlink directory listing.
-        const entries = Object.entries(shortlinks);
-        document.body.innerHTML = `<ul>${
-          entries
-            .map(
-              ([k, v]) =>
-                `<li><code>${k}</code> → <a href="?${k}">${v}</a></li>`,
-            )
-            .join("")
-        }</ul>`;
-      }
+    import { go } from "@fartlabs/go";
+    const shortlinks = JSON.parse(
+      document.getElementById("shortlinks").textContent,
+    );
+    const url = new URL(window.location.href);
+    const result = go(url, shortlinks);
+    if (result.href !== url.href) {
+      // Redirect via meta-refresh
+      document.open();
+      document.write(`<!DOCTYPE html>
+    <html>
+    <head>
+      <meta http-equiv="refresh" content="0;url=${result.href}">
+      <title>Redirecting…</title>
+    </head>
+    <body>
+      <p>Resolving <code>${url.href}</code> → <a href="${result.href}">${result.href}</a></p>
+    </body>
+    </html>`);
+      document.close();
+    } else {
+      // Render shortlink directory listing.
+      const entries = Object.entries(shortlinks);
+      document.body.innerHTML = `<ul>${
+        entries
+          .map(
+            ([k, v]) => `<li><code>${k}</code> → <a href="?${k}">${v}</a></li>`,
+          )
+          .join("")
+      }</ul>`;
+    }
     </script>
   </body>
 </html>

links.json

@@ -1,6 +1,10 @@
 {
   "api": "https://api.example.com",
+  "chat": "https://discord.gg/ZwHaZ63yq3",
   "docs": "/documentation",
   "github": "https://github.com",
+  "in": "https://linkedin.com/company/fartlabs",
+  "instagram": "https://instagram.com/fartlabs",
+  "twitter": "https://x.com/fartlabs_org",
   "yt": "https://youtube.com"
 }