From d49601c54e0c8f1aad8ac63079a930f36661e5bb Mon Sep 17 00:00:00 2001
From: cottongin <cottongin@users.noreply.github.com>
Date: Mon, 23 Mar 2026 11:30:48 -0400
Subject: [PATCH] feat: add offset pagination and X-Prev-Last-Date header to
 GET /sessions

Made-with: Cursor
---
 backend/routes/sessions.js        | 22 ++++++++
 tests/api/session-archive.test.js | 91 +++++++++++++++++++++++++++++++
 2 files changed, 113 insertions(+)

diff --git a/backend/routes/sessions.js b/backend/routes/sessions.js
index bc70cd3..a00cd0a 100644
--- a/backend/routes/sessions.js
+++ b/backend/routes/sessions.js
@@ -23,6 +23,9 @@ router.get('/', (req, res) => {
   try {
     const filter = req.query.filter || 'default';
     const limitParam = req.query.limit || 'all';
+    const offsetParam = req.query.offset || '0';
+    let offset = parseInt(offsetParam, 10);
+    if (isNaN(offset) || offset < 0) offset = 0;
 
     let whereClause = '';
     if (filter === 'default') {
@@ -45,6 +48,11 @@ router.get('/', (req, res) => {
       }
     }
 
+    let offsetClause = '';
+    if (offset > 0) {
+      offsetClause = `OFFSET ${offset}`;
+    }
+
     const sessions = db.prepare(`
       SELECT 
         s.id,
@@ -60,6 +68,7 @@ router.get('/', (req, res) => {
       GROUP BY s.id
       ORDER BY s.created_at DESC
       ${limitClause}
+      ${offsetClause}
     `).all();
 
     const result = sessions.map(({ notes, ...session }) => {
@@ -69,6 +78,19 @@ router.get('/', (req, res) => {
 
     const absoluteTotal = db.prepare('SELECT COUNT(*) as total FROM sessions').get();
 
+    if (offset > 0) {
+      const prevRow = db.prepare(`
+        SELECT s.created_at
+        FROM sessions s
+        ${whereClause}
+        ORDER BY s.created_at DESC
+        LIMIT 1 OFFSET ${offset - 1}
+      `).get();
+      if (prevRow) {
+        res.set('X-Prev-Last-Date', prevRow.created_at);
+      }
+    }
+
     res.set('X-Total-Count', String(countRow.total));
     res.set('X-Absolute-Total', String(absoluteTotal.total));
     res.json(result);
diff --git a/tests/api/session-archive.test.js b/tests/api/session-archive.test.js
index e76a235..0a7b742 100644
--- a/tests/api/session-archive.test.js
+++ b/tests/api/session-archive.test.js
@@ -92,6 +92,97 @@ describe('GET /api/sessions — filter and limit', () => {
     expect(res.status).toBe(200);
     expect(res.body).toHaveLength(8);
   });
+
+  test('offset skips the first N sessions', async () => {
+    for (let i = 0; i < 5; i++) {
+      seedSession({ is_active: 0, notes: null });
+    }
+
+    const allRes = await request(app).get('/api/sessions?filter=all&limit=all');
+    const offsetRes = await request(app).get('/api/sessions?filter=all&limit=2&offset=2');
+    expect(offsetRes.status).toBe(200);
+    expect(offsetRes.body).toHaveLength(2);
+    expect(offsetRes.body[0].id).toBe(allRes.body[2].id);
+    expect(offsetRes.body[1].id).toBe(allRes.body[3].id);
+  });
+
+  test('offset defaults to 0 when not provided', async () => {
+    for (let i = 0; i < 3; i++) {
+      seedSession({ is_active: 0, notes: null });
+    }
+
+    const res = await request(app).get('/api/sessions?filter=all&limit=2');
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveLength(2);
+  });
+
+  test('negative offset is clamped to 0', async () => {
+    seedSession({ is_active: 0, notes: null });
+
+    const res = await request(app).get('/api/sessions?filter=all&offset=-5');
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveLength(1);
+  });
+
+  test('non-numeric offset is clamped to 0', async () => {
+    seedSession({ is_active: 0, notes: null });
+
+    const res = await request(app).get('/api/sessions?filter=all&offset=abc');
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveLength(1);
+  });
+
+  test('offset past end returns empty array', async () => {
+    seedSession({ is_active: 0, notes: null });
+
+    const res = await request(app).get('/api/sessions?filter=all&limit=5&offset=100');
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveLength(0);
+    expect(res.headers['x-total-count']).toBe('1');
+  });
+
+  test('X-Prev-Last-Date header is set with correct value when offset > 0', async () => {
+    for (let i = 0; i < 5; i++) {
+      seedSession({ is_active: 0, notes: null });
+    }
+
+    const allRes = await request(app).get('/api/sessions?filter=all&limit=all');
+    const res = await request(app).get('/api/sessions?filter=all&limit=2&offset=2');
+    expect(res.headers['x-prev-last-date']).toBe(allRes.body[1].created_at);
+  });
+
+  test('X-Prev-Last-Date header is absent when offset is 0', async () => {
+    seedSession({ is_active: 0, notes: null });
+
+    const res = await request(app).get('/api/sessions?filter=all&limit=2');
+    expect(res.headers['x-prev-last-date']).toBeUndefined();
+  });
+
+  test('X-Total-Count is unaffected by offset', async () => {
+    for (let i = 0; i < 10; i++) {
+      seedSession({ is_active: 0, notes: null });
+    }
+
+    const res = await request(app).get('/api/sessions?filter=all&limit=3&offset=6');
+    expect(res.headers['x-total-count']).toBe('10');
+    expect(res.body).toHaveLength(3);
+  });
+
+  test('offset works with filter=default', async () => {
+    for (let i = 0; i < 5; i++) {
+      seedSession({ is_active: 0, notes: null });
+    }
+    const archived = seedSession({ is_active: 0, notes: null });
+    require('../helpers/test-utils').db.prepare(
+      'UPDATE sessions SET archived = 1 WHERE id = ?'
+    ).run(archived.id);
+
+    const res = await request(app).get('/api/sessions?filter=default&limit=2&offset=2');
+    expect(res.status).toBe(200);
+    expect(res.body).toHaveLength(2);
+    expect(res.headers['x-total-count']).toBe('5');
+    res.body.forEach(s => expect(s.archived).toBe(0));
+  });
 });
 
 describe('POST /api/sessions/:id/archive', () => {