init

packages/svelte/__tests__/use-swr.test.ts

@@ -0,0 +1,53 @@
+import { describe, expect, it, vi, beforeEach, afterEach } from "bun:test";
+import { get } from "svelte/store";
+import { useSWR } from "../index";
+
+// Mock fetcher
+const fetcher = vi.fn((key: string) => Promise.resolve(`data-${key}`));
+
+describe("useSWR (Svelte)", () => {
+    beforeEach(() => {
+        vi.useFakeTimers();
+        fetcher.mockClear();
+    });
+
+    afterEach(() => {
+        vi.useRealTimers();
+    });
+
+    it("fetches data on mount", async () => {
+        const { data, isLoading } = useSWR("test-key", fetcher);
+
+        // Initial state (synchronously set by my core change)
+        expect(get(isLoading)).toBe(true);
+
+        // Wait for fetch
+        vi.runAllTimers();
+
+        expect(get(data)).toBe("data-test-key");
+        expect(get(isLoading)).toBe(false);
+    });
+
+    it("deduplicates requests", async () => {
+        const { data: d1 } = useSWR("dedupe-key", fetcher);
+        const { data: d2 } = useSWR("dedupe-key", fetcher);
+
+        vi.runAllTimers();
+
+        expect(fetcher).toHaveBeenCalledTimes(1);
+        expect(get(d1)).toBe("data-dedupe-key");
+        expect(get(d2)).toBe("data-dedupe-key");
+    });
+
+    it("mutates data manually", async () => {
+        const { data, mutate } = useSWR("mutate-key", fetcher);
+
+        vi.runAllTimers();
+
+        expect(get(data)).toBe("data-mutate-key");
+
+        await mutate("new-data");
+
+        expect(get(data)).toBe("new-data");
+    });
+});