perf: deduplicate changelog authors per day with a set

resources/js/lib/changelog.ts

@@ -43,6 +43,7 @@ export function changelogDays(
     timeZone: string,
 ): ChangelogDay[] {
     const days: ChangelogDay[] = [];
+    let seenAuthors = new Set<string>();
 
     for (const commit of commits) {
         const date = new Date(commit.committed_at).toLocaleDateString('en-CA', {
@@ -53,13 +54,13 @@ export function changelogDays(
         if (day?.date !== date) {
             day = { date, commits: [], authors: [] };
             days.push(day);
+            seenAuthors = new Set();
         }
 
         day.commits.push(commit);
 
-        if (
-            !day.authors.some((author) => author.login === commit.author.login)
-        ) {
+        if (!seenAuthors.has(commit.author.login)) {
+            seenAuthors.add(commit.author.login);
             day.authors.push(commit.author);
         }
     }

tests/Unit/Changelog.test.ts

@@ -94,3 +94,14 @@ void test('names the day relative to today in the reader’s time zone', () => {
     assert.deepEqual(changelogDayHeading('2026-10-14', 'Europe/Budapest', now), { title: 'Wednesday', date: 'Oct 14' });
     assert.deepEqual(changelogDayHeading('2025-12-31', 'Europe/Budapest', now), { title: 'Wednesday', date: 'Dec 31, 2025' });
 });
+
+void test('keeps the first author occurrence even for many commits on the same day', () => {
+    const commits = Array.from({ length: 200 }, (_, index) =>
+        commit(index, '2026-10-18T12:00:00Z', index % 2 === 0 ? 'alice' : 'bob'),
+    );
+    const days = changelogDays(commits, 'UTC');
+
+    assert.equal(days.length, 1);
+    assert.equal(days[0].commits.length, 200);
+    assert.deepEqual(days[0].authors.map(({ login }) => login), ['alice', 'bob']);
+});