refactor(server): move the identified Places request into a file of its own

The instance token and the request that carries the installation key leave trek-places.client.ts, which had grown past the 1000-line limit.

server/src/nest/maps/trek-places.client.ts

@@ -12,9 +12,9 @@
  * refused key falls back to the shared pool. The failure modes stay the network
  * and the service being down, both of which fall back to what TREK did before.
  */
-import { readEnv, getAppUrl } from '../../app-config';
-import { serviceIdentitySlot } from '../service-identity/service-identity.interface';
+import { readEnv } from '../../app-config';
 import { toApiLang } from './maps.helpers';
+import { identifiedFetch } from './trek-places.fetch';
 import {
   normalizePlaceWebsite,
   skiRouteBuildSchema,
@@ -106,28 +106,6 @@ export interface TrekPlacesSearchResponse {
   results: TrekPlace[];
 }
 
-/**
- * One opaque string per instance, so the service can rate-limit per caller
- * instead of per IP. Derived from the instance URL rather than generated and
- * stored: it must be stable across restarts, and it must not be anything that
- * identifies a person. It is never resolved back to anything on the far side.
- */
-function instanceToken(): string {
-  // getAppUrl(), not the raw APP_URL. The variable is commented out in the
-  // shipped compose file, so reading it raw gave every default install the same
-  // string — and a token every caller shares is not a caller. One install
-  // running a large import would then rate-limit all the others, who would fall
-  // back to Nominatim with nothing to point at. The resolver falls through to
-  // ALLOWED_ORIGINS and then to the port, so an unconfigured instance still
-  // differs from its neighbours.
-  const url = getAppUrl();
-  let hash = 0;
-  for (let i = 0; i < url.length; i++) {
-    hash = ((hash << 5) - hash + url.charCodeAt(i)) | 0;
-  }
-  return `trek-${(hash >>> 0).toString(36)}`;
-}
-
 /**
  * Stop asking a service that is not answering.
  *
@@ -255,26 +233,6 @@ function noteFailure(err: unknown, breaker: Breaker): void {
   }
 }
 
-/**
- * A request carrying who is asking: the instance token, and the installation
- * key where it may go. A refused key costs no answer: the request goes once
- * more without it, through the shared pool, while the identity counts the refusal.
- */
-async function identifiedFetch(url: URL, headers: Record<string, string>, signal: AbortSignal): Promise<Response> {
-  const identity = serviceIdentitySlot.get();
-  const own = identity.headersFor(url);
-  const base = { ...headers, 'X-TREK-Instance': instanceToken() };
-  const res = await fetch(url, { signal, headers: { ...base, ...own } });
-  identity.observe(url, res);
-  if (res.status !== 401 || !own.Authorization) return res;
-  await res.body?.cancel();
-  return fetch(url, { signal, headers: { ...base, ...withoutKey(own) } });
-}
-
-function withoutKey(headers: Record<string, string>): Record<string, string> {
-  return Object.fromEntries(Object.entries(headers).filter(([name]) => name !== 'Authorization'));
-}
-
 function statusError(status: number): Error & { status: number } {
   const err = new Error(`TREK Places API ${status}`) as Error & { status: number };
   err.status = status;

server/src/nest/maps/trek-places.fetch.ts

@@ -0,0 +1,48 @@
+import { getAppUrl } from '../../app-config';
+import { serviceIdentitySlot } from '../service-identity/service-identity.interface';
+
+/**
+ * A request carrying who is asking: the instance token, and the installation
+ * key where it may go. A refused key costs no answer: the request goes once
+ * more without it, through the shared pool, while the identity counts the refusal.
+ */
+export async function identifiedFetch(
+  url: URL,
+  headers: Record<string, string>,
+  signal: AbortSignal,
+): Promise<Response> {
+  const identity = serviceIdentitySlot.get();
+  const own = identity.headersFor(url);
+  const base = { ...headers, 'X-TREK-Instance': instanceToken() };
+  const res = await fetch(url, { signal, headers: { ...base, ...own } });
+  identity.observe(url, res);
+  if (res.status !== 401 || !own.Authorization) return res;
+  await res.body?.cancel();
+  return fetch(url, { signal, headers: { ...base, ...withoutKey(own) } });
+}
+
+function withoutKey(headers: Record<string, string>): Record<string, string> {
+  return Object.fromEntries(Object.entries(headers).filter(([name]) => name !== 'Authorization'));
+}
+
+/**
+ * One opaque string per instance, so the service can rate-limit per caller
+ * instead of per IP. Derived from the instance URL rather than generated and
+ * stored: it must be stable across restarts, and it must not be anything that
+ * identifies a person. It is never resolved back to anything on the far side.
+ */
+function instanceToken(): string {
+  // getAppUrl(), not the raw APP_URL. The variable is commented out in the
+  // shipped compose file, so reading it raw gave every default install the same
+  // string — and a token every caller shares is not a caller. One install
+  // running a large import would then rate-limit all the others, who would fall
+  // back to Nominatim with nothing to point at. The resolver falls through to
+  // ALLOWED_ORIGINS and then to the port, so an unconfigured instance still
+  // differs from its neighbours.
+  const url = getAppUrl();
+  let hash = 0;
+  for (let i = 0; i < url.length; i++) {
+    hash = ((hash << 5) - hash + url.charCodeAt(i)) | 0;
+  }
+  return `trek-${(hash >>> 0).toString(36)}`;
+}