First version of Karten App

src/karte/fakes.ts

@@ -0,0 +1,66 @@
+import type { CachePort, KachelPort, MarksPort } from "./types";
+
+export function createMemoryCache(initial: string[] = []): CachePort {
+  const ids = new Set(initial);
+  return {
+    async ids() {
+      return [...ids];
+    },
+    async put(id) {
+      ids.add(id);
+    },
+    async delete(drop) {
+      for (const id of drop) ids.delete(id);
+    },
+  };
+}
+
+export function createMemoryMarks(initial: string[] = []): MarksPort {
+  let heruntergeladen = [...initial];
+  return {
+    async read() {
+      return { heruntergeladen: [...heruntergeladen] };
+    },
+    async write(state) {
+      heruntergeladen = [...state.heruntergeladen];
+    },
+  };
+}
+
+type Job = {
+  resolve: (bytes: Uint8Array) => void;
+  reject: (error: unknown) => void;
+  settled: boolean;
+};
+
+/** Completes the oldest in-flight Kachel fetch when `tick` is called. */
+export function createFetchClock(): KachelPort & { tick: () => Promise<void> } {
+  const queue: Job[] = [];
+  return {
+    fetch(_id, signal) {
+      return new Promise((resolve, reject) => {
+        const job: Job = { resolve, reject, settled: false };
+        const abort = () => {
+          if (job.settled) return;
+          job.settled = true;
+          const index = queue.indexOf(job);
+          if (index >= 0) queue.splice(index, 1);
+          reject(new DOMException("The operation was aborted.", "AbortError"));
+        };
+        if (signal.aborted) {
+          abort();
+          return;
+        }
+        signal.addEventListener("abort", abort, { once: true });
+        queue.push(job);
+      });
+    },
+    async tick() {
+      const job = queue.shift();
+      if (!job || job.settled) return;
+      job.settled = true;
+      job.resolve(new Uint8Array([7]));
+      for (let step = 0; step < 20; step += 1) await Promise.resolve();
+    },
+  };
+}