Cache map & countries

packages/playground/src/main.ts

@@ -11,6 +11,10 @@ import { defineGlobals } from "./config";
 import Monitor from "./Monitor.vue";
 import router from "./router";
 import { normalizeError } from "./utils/helpers";
+import { setupMapCache } from "./utils/mapCache";
+
+setupMapCache();
+
 const app = createApp(Monitor);
 
 app.config.errorHandler = error => {

packages/playground/src/utils/mapCache.ts

@@ -0,0 +1,64 @@
+/**
+ * Cache configuration for map-related resources
+ */
+const CACHE_CONFIG = [
+  {
+    pattern: (url: string) => url.endsWith("/all.csv") && url.includes("ISO-3166"),
+    contentType: "text/csv",
+  },
+  {
+    pattern: (url: string) => url.includes("countries-110m.json") || url.endsWith("/110m.json"),
+    contentType: "application/json",
+  },
+] as const;
+
+const cache = new Map<string, string>();
+const promises = new Map<string, Promise<string>>();
+const originalFetch = window.fetch;
+
+async function getCached(url: string): Promise<string> {
+  if (cache.has(url)) {
+    return cache.get(url)!;
+  }
+
+  if (promises.has(url)) {
+    return promises.get(url)!;
+  }
+
+  const promise = originalFetch(url)
+    .then(res => res.text())
+    .then(text => {
+      cache.set(url, text);
+      return text;
+    })
+    .finally(() => {
+      promises.delete(url);
+    });
+
+  promises.set(url, promise);
+  return promise;
+}
+
+function getUrlString(input: RequestInfo | URL): string {
+  if (typeof input === "string") return input;
+  if (input instanceof URL) return input.href;
+  return input.url;
+}
+
+export function setupMapCache(): void {
+  window.fetch = async function (input: RequestInfo | URL, init?: RequestInit): Promise<Response> {
+    const url = getUrlString(input);
+
+    for (const config of CACHE_CONFIG) {
+      if (config.pattern(url)) {
+        const content = await getCached(url);
+        return new Response(content, {
+          status: 200,
+          headers: { "Content-Type": config.contentType },
+        });
+      }
+    }
+
+    return originalFetch(input, init);
+  };
+}