feat: add database layer with SQLite CRUD

tests/database.test.ts

@@ -0,0 +1,79 @@
+import { initDatabase, insertMeasurement, getAllMeasurements, getLatestMeasurement, updateMeasurement } from '../src/database/db'
+import { Measurement } from '../src/types'
+import * as SQLite from 'expo-sqlite'
+
+jest.mock('expo-sqlite', () => ({
+  openDatabaseAsync: jest.fn(),
+}))
+
+const mockMeasurement: Measurement = {
+  id: '550e8400-e29b-41d4-a716-446655440000',
+  weight: 75.5,
+  bmi: 22.3,
+  bodyFatPercentage: 15.2,
+  fatMass: 11.5,
+  musclePercentage: 40.1,
+  muscleMass: 30.3,
+  visceralFat: 8,
+  bmr: 1650,
+  measuredAt: '2024-01-01T08:00:00.000Z',
+  createdAt: '2024-01-01T08:00:00.000Z',
+  updatedAt: '2024-01-01T08:00:00.000Z',
+  syncStatus: 'local',
+}
+
+describe('database', () => {
+  let db: any
+
+  beforeEach(() => {
+    db = {
+      execAsync: jest.fn(),
+      runAsync: jest.fn(),
+      getAllAsync: jest.fn(),
+    }
+    ;(SQLite.openDatabaseAsync as jest.Mock).mockResolvedValue(db)
+  })
+
+  it('initDatabase creates the measurements table', async () => {
+    await initDatabase()
+    expect(db.execAsync).toHaveBeenCalledWith(
+      expect.stringContaining('CREATE TABLE IF NOT EXISTS measurements')
+    )
+  })
+
+  it('insertMeasurement inserts a row', async () => {
+    db.runAsync.mockResolvedValue(undefined)
+    await initDatabase()
+    await insertMeasurement(mockMeasurement)
+    expect(db.runAsync).toHaveBeenCalledWith(
+      expect.stringContaining('INSERT INTO measurements'),
+      expect.arrayContaining([mockMeasurement.id])
+    )
+  })
+
+  it('getAllMeasurements returns all measurements ordered by measuredAt desc', async () => {
+    db.getAllAsync.mockResolvedValue([{ ...mockMeasurement }])
+    await initDatabase()
+    const result = await getAllMeasurements()
+    expect(result).toHaveLength(1)
+    expect(result[0].id).toBe(mockMeasurement.id)
+  })
+
+  it('getLatestMeasurement returns the most recent', async () => {
+    db.getAllAsync.mockResolvedValue([{ ...mockMeasurement }])
+    await initDatabase()
+    const result = await getLatestMeasurement()
+    expect(result).not.toBeNull()
+    expect(result!.id).toBe(mockMeasurement.id)
+  })
+
+  it('updateMeasurement updates syncStatus', async () => {
+    db.runAsync.mockResolvedValue(undefined)
+    await initDatabase()
+    await updateMeasurement(mockMeasurement.id, 'synced')
+    expect(db.runAsync).toHaveBeenCalledWith(
+      expect.stringContaining('UPDATE measurements'),
+      expect.arrayContaining(['synced', mockMeasurement.id])
+    )
+  })
+})