feat: add persistent responsive color themes

2026-07-26 00:06:49 +09:00
parent bee5c158c6
commit 4cfbe5a29e
9 changed files with 372 additions and 51 deletions
@@ -0,0 +1,44 @@
+// @vitest-environment jsdom
+
+import { describe, expect, it } from "vitest";
+
+import {
+  normalizeColorSchemePreference,
+  resolveColorScheme,
+} from "../../src/application/policies/color-scheme.js";
+import { initializeColorScheme } from "../../src/bootstrap/initialize-color-scheme.js";
+
+describe("color scheme policy", () => {
+  it("normalizes unknown persisted values to the safe system default", () => {
+    expect(normalizeColorSchemePreference("sepia")).toBe("system");
+    expect(normalizeColorSchemePreference("dark")).toBe("dark");
+  });
+
+  it("resolves system and explicit preferences deterministically", () => {
+    expect(resolveColorScheme("system", true)).toBe("dark");
+    expect(resolveColorScheme("system", false)).toBe("light");
+    expect(resolveColorScheme("light", true)).toBe("light");
+  });
+
+  it("applies a persisted preference before application paint", () => {
+    const storage = {
+      read: () => ({ ok: true, value: "system" }),
+      write: () => ({ ok: true }),
+      remove: () => ({ ok: true }),
+    };
+
+    const result = initializeColorScheme(storage, {
+      documentElement: document.documentElement,
+      matchMedia: () =>
+        /** @type {MediaQueryList} */ ({ matches: true }),
+    });
+
+    expect(result).toEqual({ preference: "system", resolved: "dark" });
+    expect(document.documentElement).toHaveAttribute("data-theme", "dark");
+    expect(document.documentElement).toHaveAttribute(
+      "data-theme-preference",
+      "system",
+    );
+    expect(document.documentElement.style.colorScheme).toBe("dark");
+  });
+});