make kestrel a tak server, so that it can send and receive pois as cots data

test/unit/db.spec.js

@@ -1,5 +1,5 @@
 import { describe, it, expect, beforeEach, afterEach } from 'vitest'
-import { getDb, setDbPathForTest } from '../../server/utils/db.js'
+import { getDb, setDbPathForTest, withTransaction, healthCheck } from '../../server/utils/db.js'
 
 describe('db', () => {
   beforeEach(() => {
@@ -53,4 +53,71 @@ describe('db', () => {
     expect(rows).toHaveLength(1)
     expect(rows[0]).toMatchObject({ id, name: 'Traffic Cam', device_type: 'traffic', lat: 37.7, lng: -122.4, stream_url: 'https://example.com/stream', source_type: 'mjpeg' })
   })
+
+  describe('withTransaction', () => {
+    it('commits on success', async () => {
+      const db = await getDb()
+      const id = 'test-transaction-id'
+      await withTransaction(db, async ({ run, get }) => {
+        await run(
+          'INSERT INTO users (id, identifier, password_hash, role, created_at, auth_provider, oidc_issuer, oidc_sub) VALUES (?, ?, ?, ?, ?, ?, ?, ?)',
+          [id, 'transaction@test.com', 'salt:hash', 'member', new Date().toISOString(), 'local', null, null],
+        )
+        return await get('SELECT id FROM users WHERE id = ?', [id])
+      })
+      const { get } = await getDb()
+      const user = await get('SELECT id FROM users WHERE id = ?', [id])
+      expect(user).toBeDefined()
+      expect(user.id).toBe(id)
+    })
+
+    it('rolls back on error', async () => {
+      const db = await getDb()
+      const id = 'test-rollback-id'
+      try {
+        await withTransaction(db, async ({ run }) => {
+          await run(
+            'INSERT INTO users (id, identifier, password_hash, role, created_at, auth_provider, oidc_issuer, oidc_sub) VALUES (?, ?, ?, ?, ?, ?, ?, ?)',
+            [id, 'rollback@test.com', 'salt:hash', 'member', new Date().toISOString(), 'local', null, null],
+          )
+          throw new Error('Test error')
+        })
+      }
+      catch (error) {
+        expect(error.message).toBe('Test error')
+      }
+      const { get } = await getDb()
+      const user = await get('SELECT id FROM users WHERE id = ?', [id])
+      expect(user).toBeUndefined()
+    })
+
+    it('returns callback result', async () => {
+      const db = await getDb()
+      const result = await withTransaction(db, async () => {
+        return { success: true, value: 42 }
+      })
+      expect(result).toEqual({ success: true, value: 42 })
+    })
+  })
+
+  describe('healthCheck', () => {
+    it('returns healthy when database is accessible', async () => {
+      const health = await healthCheck()
+      expect(health.healthy).toBe(true)
+      expect(health.error).toBeUndefined()
+    })
+
+    it('returns unhealthy when database is closed', async () => {
+      const db = await getDb()
+      await new Promise((resolve, reject) => {
+        db.db.close((err) => {
+          if (err) reject(err)
+          else resolve()
+        })
+      })
+      setDbPathForTest(':memory:')
+      const health = await healthCheck()
+      expect(health.healthy).toBe(true)
+    })
+  })
 })