From a633b79aa5a0f9109237e7be2cdb010f8be092ad Mon Sep 17 00:00:00 2001
From: Cameron Pfiffer <cameron@pfiffer.org>
Date: Thu, 27 Aug 2026 17:49:39 -0700
Subject: [PATCH] Preserve HTTPS across slash redirects.
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Use relative canonical locations so the Fly reverse proxy cannot leak its internal HTTP scheme into public redirects.

👾 Generated with [Letta Code](https://letta.com)

Co-Authored-By: Letta Code <noreply@letta.com>
---
 src/index.tsx         |  4 ++--
 src/knowledge.test.ts | 12 ++++++++----
 src/trailing-slash.ts | 13 +++++++++++++
 3 files changed, 23 insertions(+), 6 deletions(-)
 create mode 100644 src/trailing-slash.ts

diff --git a/src/index.tsx b/src/index.tsx
index 04e3067..9f42d14 100644
--- a/src/index.tsx
+++ b/src/index.tsx
@@ -1,7 +1,6 @@
 import "./env.ts";
 import { Hono } from "hono";
 import { renderToReadableStream } from "hono/jsx/streaming";
-import { trimTrailingSlash } from "hono/trailing-slash";
 import { serveStatic } from "@hono/node-server/serve-static";
 import { serve } from "@hono/node-server";
 import { Site } from "./components/site.tsx";
@@ -41,10 +40,11 @@ import {
   knowledgeRoute,
   loadKnowledgeGraph,
 } from "./knowledge.ts";
+import { canonicalizeTrailingSlash } from "./trailing-slash.ts";
 
 const app = new Hono();
 
-app.use(trimTrailingSlash({ alwaysRedirect: true }));
+app.use(canonicalizeTrailingSlash);
 
 // --- Static files ---
 app.use(
diff --git a/src/knowledge.test.ts b/src/knowledge.test.ts
index afb91ae..dfc4ff4 100644
--- a/src/knowledge.test.ts
+++ b/src/knowledge.test.ts
@@ -5,7 +5,6 @@ import { tmpdir } from "node:os";
 import { join } from "node:path";
 import test from "node:test";
 import { Hono } from "hono";
-import { trimTrailingSlash } from "hono/trailing-slash";
 import { KnowledgeVideo } from "./components/knowledge-entry.tsx";
 import {
   knowledgeContentDigest,
@@ -14,6 +13,7 @@ import {
   loadKnowledgeGraph,
   parseKnowledgeDocument,
 } from "./knowledge.ts";
+import { canonicalizeTrailingSlash } from "./trailing-slash.ts";
 
 function draftSource(slug: string, route?: string): string {
   return `---
@@ -180,17 +180,21 @@ test("captures multiple knowledge path segments in Hono", async () => {
 
 test("redirects trailing slashes to canonical Knowledge URLs", async () => {
   const app = new Hono();
-  app.use(trimTrailingSlash({ alwaysRedirect: true }));
+  app.use(canonicalizeTrailingSlash);
   app.get("/knowledge", (context) => context.text("knowledge"));
   app.get("/knowledge/:route{.+}", (context) => context.text(context.req.param("route")));
 
   const landing = await app.request("https://cameron.stream/knowledge/?view=map");
   assert.equal(landing.status, 301);
-  assert.equal(landing.headers.get("location"), "https://cameron.stream/knowledge?view=map");
+  assert.equal(landing.headers.get("location"), "/knowledge?view=map");
 
   const entry = await app.request("https://cameron.stream/knowledge/agent-memory/");
   assert.equal(entry.status, 301);
-  assert.equal(entry.headers.get("location"), "https://cameron.stream/knowledge/agent-memory");
+  assert.equal(entry.headers.get("location"), "/knowledge/agent-memory");
+
+  const head = await app.request("https://cameron.stream/knowledge/", { method: "HEAD" });
+  assert.equal(head.status, 301);
+  assert.equal(head.headers.get("location"), "/knowledge");
 });
 
 test("indexes canonical nested routes and rejects route collisions", async () => {
diff --git a/src/trailing-slash.ts b/src/trailing-slash.ts
new file mode 100644
index 0000000..89614d9
--- /dev/null
+++ b/src/trailing-slash.ts
@@ -0,0 +1,13 @@
+import type { MiddlewareHandler } from "hono";
+
+export const canonicalizeTrailingSlash: MiddlewareHandler = async (context, next) => {
+  const path = context.req.path;
+  const method = context.req.method;
+
+  if ((method === "GET" || method === "HEAD") && path !== "/" && path.endsWith("/")) {
+    const { search } = new URL(context.req.url);
+    return context.redirect(`${path.slice(0, -1)}${search}`, 301);
+  }
+
+  await next();
+};
-- 
2.51.2