fix: avoid repeated daily starlanguage refresh

frontend/tests/profile-state.test.ts

@@ -0,0 +1,52 @@
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import test from "node:test";
+import { preserveShallowEqual } from "../src/lib/preserve-shallow-equal.ts";
+
+const pageSource = readFileSync(new URL("../src/app/page.tsx", import.meta.url), "utf8");
+
+test("preserves the current profile reference when refreshed values are unchanged", () => {
+  const current = {
+    name: "测试用户",
+    date: "2000-01-01",
+    time: "",
+    birthTimeSource: "period_only",
+    birthTimePeriod: "evening",
+    timezoneId: "Asia/Shanghai",
+    latitude: 31.23,
+    longitude: 121.47,
+    timezoneOffset: null,
+  };
+  const refreshed = { ...current };
+
+  assert.notEqual(refreshed, current);
+  assert.equal(preserveShallowEqual(current, refreshed), current);
+});
+
+test("uses the refreshed profile reference when a value changed", () => {
+  const current = {
+    name: "测试用户",
+    birthTimePeriod: "evening",
+    timezoneId: "Asia/Shanghai",
+  };
+  const refreshed = {
+    ...current,
+    birthTimePeriod: "morning",
+  };
+
+  assert.equal(preserveShallowEqual(current, refreshed), refreshed);
+});
+
+test("account refresh preserves an equivalent normalized profile instead of replacing it", () => {
+  const refreshAccountStart = pageSource.indexOf("async function refreshAccount()");
+  const refreshAccountSource = pageSource.slice(
+    refreshAccountStart,
+    pageSource.indexOf("function updateSession", refreshAccountStart),
+  );
+
+  assert.match(
+    refreshAccountSource,
+    /setProfile\(\(current\) => preserveShallowEqual\(current, nextProfile\)\)/,
+  );
+  assert.doesNotMatch(refreshAccountSource, /setProfile\(nextProfile\)/);
+});