test: cover theme persistence helpers

src/lib/__tests__/theme.test.ts

@@ -1,73 +1,73 @@
-import { effectiveTheme, readTheme, writeTheme } from "../theme";
-
-const originalLocalStorage = window.localStorage;
-const originalMatchMedia = window.matchMedia;
-
-function replaceLocalStorage(storage: Partial<Storage>) {
-  Object.defineProperty(window, "localStorage", {
-    configurable: true,
-    value: storage,
-  });
-}
-
-afterEach(() => {
-  Object.defineProperty(window, "localStorage", {
-    configurable: true,
-    value: originalLocalStorage,
-  });
-  window.localStorage.clear();
-  window.matchMedia = originalMatchMedia;
-  jest.restoreAllMocks();
-});
-
-describe("theme storage helpers", () => {
-  it("round-trips valid stored themes", () => {
-    writeTheme("dark");
-
-    expect(window.localStorage.getItem("stableroute.theme")).toBe("dark");
-    expect(readTheme()).toBe("dark");
-  });
-
-  it("falls back to system for missing or corrupted stored values", () => {
-    expect(readTheme()).toBe("system");
-
-    window.localStorage.setItem("stableroute.theme", "midnight");
-    expect(readTheme()).toBe("system");
-  });
-
-  it("falls back to system when localStorage.getItem throws", () => {
-    replaceLocalStorage({
-      getItem: jest.fn(() => {
-        throw new Error("storage disabled");
-      }),
-    });
-
-    expect(readTheme()).toBe("system");
-  });
-
-  it("treats write failures as a no-op", () => {
-    const setItem = jest.fn(() => {
-      throw new Error("quota exceeded");
-    });
-    replaceLocalStorage({ setItem });
-
-    expect(() => writeTheme("light")).not.toThrow();
-    expect(setItem).toHaveBeenCalledWith("stableroute.theme", "light");
-  });
-});
-
-describe("effectiveTheme", () => {
-  it("returns explicit light or dark themes without media queries", () => {
-    expect(effectiveTheme("light")).toBe("light");
-    expect(effectiveTheme("dark")).toBe("dark");
-  });
-
-  it("resolves system through prefers-color-scheme", () => {
-    window.matchMedia = jest.fn().mockReturnValue({ matches: true });
-
-    expect(effectiveTheme("system")).toBe("dark");
-    expect(window.matchMedia).toHaveBeenCalledWith(
-      "(prefers-color-scheme: dark)",
-    );
-  });
-});
+import { effectiveTheme, readTheme, writeTheme } from "../theme";
+
+const originalLocalStorage = window.localStorage;
+const originalMatchMedia = window.matchMedia;
+
+function replaceLocalStorage(storage: Partial<Storage>) {
+  Object.defineProperty(window, "localStorage", {
+    configurable: true,
+    value: storage,
+  });
+}
+
+afterEach(() => {
+  Object.defineProperty(window, "localStorage", {
+    configurable: true,
+    value: originalLocalStorage,
+  });
+  window.localStorage.clear();
+  window.matchMedia = originalMatchMedia;
+  jest.restoreAllMocks();
+});
+
+describe("theme storage helpers", () => {
+  it("round-trips valid stored themes", () => {
+    writeTheme("dark");
+
+    expect(window.localStorage.getItem("stableroute.theme")).toBe("dark");
+    expect(readTheme()).toBe("dark");
+  });
+
+  it("falls back to system for missing or corrupted stored values", () => {
+    expect(readTheme()).toBe("system");
+
+    window.localStorage.setItem("stableroute.theme", "midnight");
+    expect(readTheme()).toBe("system");
+  });
+
+  it("falls back to system when localStorage.getItem throws", () => {
+    replaceLocalStorage({
+      getItem: jest.fn(() => {
+        throw new Error("storage disabled");
+      }),
+    });
+
+    expect(readTheme()).toBe("system");
+  });
+
+  it("treats write failures as a no-op", () => {
+    const setItem = jest.fn(() => {
+      throw new Error("quota exceeded");
+    });
+    replaceLocalStorage({ setItem });
+
+    expect(() => writeTheme("light")).not.toThrow();
+    expect(setItem).toHaveBeenCalledWith("stableroute.theme", "light");
+  });
+});
+
+describe("effectiveTheme", () => {
+  it("returns explicit light or dark themes without media queries", () => {
+    expect(effectiveTheme("light")).toBe("light");
+    expect(effectiveTheme("dark")).toBe("dark");
+  });
+
+  it("resolves system through prefers-color-scheme", () => {
+    window.matchMedia = jest.fn().mockReturnValue({ matches: true });
+
+    expect(effectiveTheme("system")).toBe("dark");
+    expect(window.matchMedia).toHaveBeenCalledWith(
+      "(prefers-color-scheme: dark)",
+    );
+  });
+});