fix: address community registry cache review

Author: RCGV1

src/lib/communityMeshes.ts

@@ -26,6 +26,16 @@ export interface CommunityMeshesResponse {
 const schema = JSON.parse(readFileSync(SCHEMA_PATH, "utf8")) as AnySchema;
 const validate = new Ajv2020({ allErrors: true }).compile(schema);
 
+const deepFreeze = <T>(value: T): T => {
+  if (value && typeof value === "object" && !Object.isFrozen(value)) {
+    Object.freeze(value);
+    for (const nested of Object.values(value as Record<string, unknown>)) {
+      deepFreeze(nested);
+    }
+  }
+  return value;
+};
+
 const validPsk = (psk: unknown): boolean => {
   if (psk === null) return true;
   if (typeof psk !== "string") return false;
@@ -123,20 +133,22 @@ export const loadCommunityMeshes = (
       throw new Error(`duplicate community id: ${communities[index].id}`);
     }
   }
-  return communities;
+  return deepFreeze(communities);
 };
 
 const communities = loadCommunityMeshes();
-const response: CommunityMeshesResponse = Object.freeze({
+const response: CommunityMeshesResponse = deepFreeze({
   apiVersion: "v1",
   schemaVersion: 1,
   generatedAt: new Date().toISOString(),
   sourceRevision: process.env.VERCEL_GIT_COMMIT_SHA ?? "local",
   communities,
 });
 
+export const registryJson = JSON.stringify(response, null, 2);
+
 export const registryEtag = `"${createHash("sha256")
-  .update(JSON.stringify(communities))
+  .update(registryJson)
   .digest("base64url")}"`;
 
 export const getCommunityMeshes = (): CommunityMeshesResponse => response;

src/routes/communityMeshes.ts

@@ -1,19 +1,31 @@
 import type { App } from "@tinyhttp/app";
 import {
   getCommunityMesh,
-  getCommunityMeshes,
   getCommunityMeshSchema,
   registryEtag,
+  registryJson,
 } from "../lib/communityMeshes.js";
 
+const ifNoneMatchMatches = (
+  header: string | undefined,
+  etag: string,
+): boolean => {
+  if (!header) return false;
+  const validators = header.match(/(?:W\/)?"[^"]*"|\*/g) ?? [];
+  return validators.some(
+    (validator) => validator === "*" || validator.replace(/^W\//, "") === etag,
+  );
+};
+
 export const CommunityMeshRoutes = (app: App): void => {
   app.get("/v1/community-meshes", (req, res) => {
     res.setHeader("Cache-Control", "public, max-age=3600");
     res.setHeader("ETag", registryEtag);
-    if (req.headers["if-none-match"] === registryEtag) {
+    if (ifNoneMatchMatches(req.headers["if-none-match"], registryEtag)) {
       return res.status(304).end();
     }
-    return res.json(getCommunityMeshes());
+    res.setHeader("Content-Type", "application/json; charset=utf-8");
+    return res.send(registryJson);
   });
 
   app.get("/v1/community-meshes/schema", (_req, res) => {

tests/communityMeshes.routes.test.ts

@@ -1,4 +1,5 @@
 import { strict as assert } from "node:assert";
+import { createHash } from "node:crypto";
 import test from "node:test";
 import { App } from "@tinyhttp/app";
 import { CommunityMeshRoutes } from "../src/routes/communityMeshes.js";
@@ -30,6 +31,11 @@ test("registry uses ETags for cache revalidation", async () => {
     const first = await fetch(`${origin}/v1/community-meshes`);
     const etag = first.headers.get("etag");
     assert.ok(etag);
+    const body = await first.text();
+    const expectedEtag = `"${createHash("sha256")
+      .update(body)
+      .digest("base64url")}"`;
+    assert.equal(etag, expectedEtag);
 
     const second = await fetch(`${origin}/v1/community-meshes`, {
       headers: { "If-None-Match": etag },
@@ -39,6 +45,25 @@ test("registry uses ETags for cache revalidation", async () => {
   });
 });
 
+test("registry accepts standard If-None-Match validator forms", async () => {
+  const app = new App();
+  CommunityMeshRoutes(app);
+
+  await withServer(app, async (origin) => {
+    const first = await fetch(`${origin}/v1/community-meshes`);
+    const etag = first.headers.get("etag");
+    assert.ok(etag);
+
+    const validators = [`W/${etag}`, `"unrelated", W/${etag}`, "*"];
+    for (const validator of validators) {
+      const response = await fetch(`${origin}/v1/community-meshes`, {
+        headers: { "If-None-Match": validator },
+      });
+      assert.equal(response.status, 304, validator);
+    }
+  });
+});
+
 test("serves the schema and returns 404 for an unknown community", async () => {
   const app = new App();
   CommunityMeshRoutes(app);

tests/communityMeshes.schema.test.ts

@@ -52,6 +52,20 @@ test("accepts a public custom-modem profile with public MQTT", () => {
   assert.equal(validate(fixture("valid-public-custom.json")), true);
 });
 
+test("loaded registry records are deeply immutable", () => {
+  withRecords([fixture("valid-public-custom.json")], (directory) => {
+    const communities = loadCommunityMeshes(directory);
+    const community = communities[0];
+    const coverage = community.coverage as { coordinates: number[][][] };
+
+    assert.equal(Object.isFrozen(communities), true);
+    assert.equal(Object.isFrozen(community), true);
+    assert.equal(Object.isFrozen(coverage), true);
+    assert.equal(Object.isFrozen(coverage.coordinates), true);
+    assert.equal(Object.isFrozen(coverage.coordinates[0][0]), true);
+  });
+});
+
 test("rejects a licensed profile with an encrypted channel", () => {
   assert.equal(validate(fixture("invalid-licensed-psk.json")), false);
 });