merge: fix: resolve streak metrics truncated by days parameter (#7941)

## Description

Fixes #7919

**Problem:**
When a user supplied the `days` parameter (e.g., `?days=30` to visually
slice the contribution graph), the calendar object was mutated *before*
the streak and monthly statistics were calculated. As a result, the
calculated `currentStreak` and `longestStreak` metrics were computed
only over the sliced subset, capping them at 30 days and ignoring any
historical streak continuation.

**Solution:**
1. Pre-calculated the user's streak stats (`fullStats`) and monthly
stats (`fullMonthlyStats`) using the full, unsliced calendar immediately
after fetching it.
2. In `versus` mode, calculated the comparator's streak stats
(`fullVersusStats`) on the full timezone-normalized calendars prior to
slicing.
3. Applied the `days` parameter slicing to the calendar arrays *after*
statistics were computed, so the visual graph reflects the sliced
timeframe while displaying the correct overall streak metrics.
4. Added a new unit test in `app/api/streak/route.test.ts` to assert
this behavior and prevent future regressions.

## Pillar

- [ ] 🎨 Pillar 1 — New Theme Design
- [ ] 📐 Pillar 2 — Geometric SVG Improvement
- [ ] 🕐 Pillar 3 — Timezone Logic Optimization
- [x] 🛠️ Other (Bug fix, refactoring, docs)

## Visual Preview

*No layout/visual changes to the SVG presets. Slicing with `?days=N`
continues to render the requested subset of days but now displays the
true, uncapped streak numbers inside the stats section.*

## Checklist before requesting a review:

- [x] I have read the `CONTRIBUTING.md` file.
- [x] I have tested these changes locally
(`localhost:3000/api/streak?user=YOUR_USERNAME`).
- [x] I have run `npm run format` and `npm run lint` locally and
resolved all errors (CI will fail otherwise).
- [x] My commits follow the Conventional Commits format (e.g.,
`feat(themes): ...`, `fix(calculate): ...`).
- [ ] I have updated `README.md` if I added a new theme or URL
parameter.
- [x] I have starred the repo.
- [x] I have made sure that i have only one commit to merge in this PR.
- [x] The SVG output matches the CommitPulse "premium quality" aesthetic
standard (no raw elements, smooth animations, correct fonts).
- [ ] (Recommended) I joined the CommitPulse Discord community for
contributor discussions, mentorship, and faster PR support.

Author: JhaSourav07

app/api/streak/route.test.ts

@@ -152,6 +152,18 @@ describe('GET /api/streak', () => {
       expect(weeks.every((w) => w.contributionDays.length <= 7)).toBe(true);
     });
 
+    it('does not truncate calculated streak stats when the days parameter is set', async () => {
+      const response = await GET(makeRequest({ user: 'octocat', days: '3', format: 'json' }));
+      expect(response.status).toBe(200);
+      const body = await response.json();
+
+      // Slicing to the last 3 days (all 0 contributions in mockCalendar)
+      expect(body.calendar.totalContributions).toBe(0);
+
+      // But streak statistics must still reflect the full 14 days calendar contributions (total 10)
+      expect(body.stats.totalContributions).toBe(10);
+    });
+
     it('returns 400 Bad Request when ?layout= is set to an unsupported format', async () => {
       const response = await GET(makeRequest({ user: 'octocat', layout: 'unsupported_layout' }));
       expect(response.status).toBe(400);

app/api/streak/route.ts

@@ -44,6 +44,7 @@ import type {
   RepoContribution,
   ExtendedContributionData,
   ContributionCalendar,
+  StreakStats,
 } from '@/types';
 import { getNormalizedThemeKey, themes } from '@/lib/svg/themes';
 import { streakParamsSchema, coerceQueryParams } from '@/lib/validations';
@@ -550,6 +551,31 @@ export async function GET(request: Request) {
       });
       clearTimeout(timeoutId);
     }
+    // Pre-calculate full, unsliced statistics first
+    let fullStats: StreakStats;
+    let fullVersusStats: StreakStats | undefined;
+    let fullWeekdayStats: StreakStats | undefined;
+
+    if (versus && versusCalendar) {
+      // Normalize both calendars to the target timezone for accurate comparison
+      const normalizedCalendar = normalizeCalendarToTimezone(calendar, timezone);
+      const normalizedVersusCalendar = normalizeCalendarToTimezone(versusCalendar, timezone);
+
+      fullStats = calculateStreak(normalizedCalendar, timezone, undefined, grace);
+      fullVersusStats = calculateStreak(normalizedVersusCalendar, timezone, undefined, grace);
+    } else {
+      fullStats = calculateStreak(calendar, timezone, undefined, grace);
+      if (normalizedView === 'weekday') {
+        const normalizedCalendar = normalizeCalendarToTimezone(calendar, timezone);
+        fullWeekdayStats = calculateStreak(normalizedCalendar, timezone, undefined, grace);
+      }
+    }
+
+    const fullMonthlyStats = calculateMonthlyStats(
+      calendar,
+      timezone,
+      getMonthlyReferenceDate(year, timezone)
+    );
     if (normalizedView !== 'monthly') {
       let effectiveDays = days;
 
@@ -567,18 +593,20 @@ export async function GET(request: Request) {
           totalContributions: filteredDays.reduce((sum, d) => sum + d.contributionCount, 0),
           weeks: chunkDaysIntoWeeks(filteredDays),
         };
+
+        if (versusCalendar) {
+          const versusDays = versusCalendar.weeks.flatMap((w) => w.contributionDays);
+          const filteredVersusDays = versusDays.slice(-effectiveDays);
+          versusCalendar = {
+            totalContributions: filteredVersusDays.reduce((sum, d) => sum + d.contributionCount, 0),
+            weeks: chunkDaysIntoWeeks(filteredVersusDays),
+          };
+        }
       }
     }
 
     // ─── JSON output mode ──────────────────────────────────────────────────
     if (format === 'json') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      const monthlyStats = calculateMonthlyStats(
-        calendar,
-        timezone,
-        getMonthlyReferenceDate(year, timezone)
-      );
-
       const secondsToMidnight = tzParam
         ? getSecondsUntilMidnightInTimezone(timezone)
         : getSecondsUntilUTCMidnight();
@@ -592,8 +620,8 @@ export async function GET(request: Request) {
 
       const jsonPayload = JSON.stringify({
         user: targetEntity,
-        stats,
-        monthlyStats,
+        stats: fullStats,
+        monthlyStats: fullMonthlyStats,
         calendar: {
           totalContributions: calendar.totalContributions,
           weeks: calendar.weeks,
@@ -632,63 +660,50 @@ export async function GET(request: Request) {
     // ─── SVG output mode (default) ──────────────────────────────────────────
     let svg = '';
     if (normalizedView === 'monthly') {
-      const stats = calculateMonthlyStats(
-        calendar,
-        timezone,
-        getMonthlyReferenceDate(year, timezone)
-      );
-      svg = generateMonthlySVG(stats, params);
+      svg = generateMonthlySVG(fullMonthlyStats, params);
     } else if (normalizedView === 'languages') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateLanguagesSVG(stats, params, repoContributions);
+      svg = generateLanguagesSVG(fullStats, params, repoContributions);
     } else if (normalizedView === 'heatmap') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateHeatmapSVG(stats, params, calendar);
+      svg = generateHeatmapSVG(fullStats, params, calendar);
     } else if (normalizedView === 'pulse') {
       // We still use calculateStreak here to efficiently parse totalContributions for the stat display,
       // even though the sparkline generator will extract its own daily 30-day timeline below.
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generatePulseSVG(stats, params, calendar);
+      svg = generatePulseSVG(fullStats, params, calendar);
     } else if (normalizedView === 'skyline') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateSkylineSVG(stats, params, calendar);
+      svg = generateSkylineSVG(fullStats, params, calendar);
     } else if (normalizedView === 'constellation') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateConstellationSVG(stats, params, calendar);
+      svg = generateConstellationSVG(fullStats, params, calendar);
     } else if (normalizedView === 'radar') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
       const hourCounts = await fetchCommitHourDistribution(user, undefined, timezone).catch(
         () => undefined
       );
-      svg = generateRadarSVG(stats, params, calendar, hourCounts);
+      svg = generateRadarSVG(fullStats, params, calendar, hourCounts);
     } else if (normalizedView === 'doughnut' || normalizedView === 'pie') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateDoughnutSVG(stats, params, calendar);
+      svg = generateDoughnutSVG(fullStats, params, calendar);
     } else if (normalizedView === 'activity_graph') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateActivityGraphSVG(stats, params, calendar);
+      svg = generateActivityGraphSVG(fullStats, params, calendar);
     } else if (normalizedView === 'commit_clock') {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
       const hourCounts = await fetchCommitHourDistribution(user, undefined, timezone).catch(() =>
         new Array(24).fill(0)
       );
-      svg = generateCommitClockSVG(hourCounts, stats, params);
+      svg = generateCommitClockSVG(hourCounts, fullStats, params);
     } else if (normalizedView === 'weekday') {
-      // ← INSERT YOUR NEW BLOCK HERE
       const normalizedCalendar = normalizeCalendarToTimezone(calendar, timezone);
-      const stats = calculateStreak(normalizedCalendar, timezone, undefined, grace);
-      svg = generateWeekdaySVG(stats, params, normalizedCalendar);
+      svg = generateWeekdaySVG(fullWeekdayStats || fullStats, params, normalizedCalendar);
     } else if (versus && versusCalendar) {
       // Normalize both calendars to the target timezone for accurate comparison
       const normalizedCalendar = normalizeCalendarToTimezone(calendar, timezone);
       const normalizedVersusCalendar = normalizeCalendarToTimezone(versusCalendar, timezone);
 
-      const stats1 = calculateStreak(normalizedCalendar, timezone, undefined, grace);
-      const stats2 = calculateStreak(normalizedVersusCalendar, timezone, undefined, grace);
-      svg = generateVersusSVG(stats1, stats2, params, normalizedCalendar, normalizedVersusCalendar);
+      svg = generateVersusSVG(
+        fullStats,
+        fullVersusStats!,
+        params,
+        normalizedCalendar,
+        normalizedVersusCalendar
+      );
     } else {
-      const stats = calculateStreak(calendar, timezone, undefined, grace);
-      svg = generateSVG(stats, params, calendar, individualCalendars);
+      svg = generateSVG(fullStats, params, calendar, individualCalendars);
     }
 
     if (servedFromStaleCache) {