test: use in-memory database for tests

src/db.ts

@@ -1,9 +1,16 @@
 import { Database } from 'bun:sqlite';
 
-export const db = new Database('tasks.db');
+// Function to get a database instance. Defaults to 'tasks.db'
+export function getDb(filename: string = 'tasks.db'): Database {
+  return new Database(filename);
+}
+
+// Default export for the main application database
+export const db = getDb();
 
-export function initializeDatabase() {
-  db.exec(`
+// Initialize function now accepts a database instance
+export function initializeDatabase(instance: Database) {
+  instance.exec(`
     CREATE TABLE IF NOT EXISTS tasks (
       id INTEGER PRIMARY KEY AUTOINCREMENT,
       description TEXT NOT NULL,

tests/unit/db.test.ts

@@ -1,19 +1,33 @@
-import { db, initializeDatabase } from '../../src/db';
-import { describe, test, expect, beforeEach } from 'bun:test';
+import { Database } from 'bun:sqlite';
+import { initializeDatabase } from '../../src/db';
+import { describe, test, expect, beforeEach, afterAll, beforeAll } from 'bun:test';
 
 describe('Database', () => {
+  let testDb: Database;
+
+  // Create an in-memory database before any tests run
+  beforeAll(() => {
+    testDb = new Database(':memory:');
+  });
+
+  // Close the database connection after all tests have run
+  afterAll(() => {
+    testDb.close();
+  });
+
   beforeEach(() => {
-    // Reset database between tests
-    db.exec('DROP TABLE IF EXISTS tasks');
-    db.exec('DROP TABLE IF EXISTS task_assignments');
-    db.exec('DROP TABLE IF EXISTS users');
-    db.exec('DROP TABLE IF EXISTS groups');
-    initializeDatabase();
+    // Reset database schema between tests by dropping tables and re-initializing
+    testDb.exec('DROP TABLE IF EXISTS tasks');
+    testDb.exec('DROP TABLE IF EXISTS task_assignments');
+    testDb.exec('DROP TABLE IF EXISTS users');
+    testDb.exec('DROP TABLE IF EXISTS groups');
+    // Initialize schema on the test database instance
+    initializeDatabase(testDb);
   });
 
   describe('Table Creation', () => {
     test('should create all required tables', () => {
-      const tables = db
+      const tables = testDb
         .query("SELECT name FROM sqlite_master WHERE type='table'")
         .all()
         .map((t: any) => t.name);
@@ -26,7 +40,7 @@ describe('Database', () => {
 
   describe('Table Schemas', () => {
     test('users table should have correct columns', () => {
-      const columns = db
+      const columns = testDb
         .query("PRAGMA table_info(users)")
         .all()
         .map((c: any) => c.name);
@@ -34,7 +48,7 @@ describe('Database', () => {
     });
 
     test('tasks table should have required columns', () => {
-      const columns = db
+      const columns = testDb
         .query("PRAGMA table_info(tasks)")
         .all()
         .map((c: any) => c.name);
@@ -45,18 +59,18 @@ describe('Database', () => {
     });
 
     test('groups table should have active flag default to true', () => {
-      db.exec(`
+      testDb.exec(`
         INSERT INTO groups (id, community_id, name)
         VALUES ('test-group', 'test-community', 'Test Group')
       `);
-      const group = db.query("SELECT active FROM groups WHERE id = 'test-group'").get();
-      expect(group.active).toBe(1);
+      const group = testDb.query("SELECT active FROM groups WHERE id = 'test-group'").get();
+      expect(group.active).toBe(1); // SQLite uses 1 for TRUE
     });
   });
 
   describe('Foreign Keys', () => {
     test('task_assignments should reference tasks', () => {
-      const fkInfo = db
+      const fkInfo = testDb
         .query("PRAGMA foreign_key_list(task_assignments)")
         .all();
       expect(fkInfo.length).toBe(1);
@@ -66,7 +80,7 @@ describe('Database', () => {
     });
 
     test('tasks should reference users via created_by', () => {
-      const fkInfo = db
+      const fkInfo = testDb
         .query("PRAGMA foreign_key_list(tasks)")
         .all();
       expect(fkInfo.length).toBe(1);
@@ -79,29 +93,30 @@ describe('Database', () => {
   describe('User Operations', () => {
     test('should reject duplicate user IDs', () => {
       // First insert should succeed
-      const firstInsert = db.prepare(`
+      const firstInsert = testDb.prepare(`
         INSERT INTO users (id) VALUES ('34650112233')
       `).run();
       expect(firstInsert.changes).toBe(1);
 
-      // Second insert with same ID should fail
+      // Second insert with same ID should fail due to PRIMARY KEY constraint
       expect(() => {
-        db.prepare(`
+        testDb.prepare(`
           INSERT INTO users (id) VALUES ('34650112233')
         `).run();
-      }).toThrow();
+      }).toThrow(); // Bun's SQLite driver throws an error on constraint violation
 
       // Verify only one record exists
-      const count = db.prepare(`
+      const countResult = testDb.prepare(`
         SELECT COUNT(*) as count FROM users WHERE id = '34650112233'
       `).get();
-      expect(count.count).toBe(1);
+      expect(countResult.count).toBe(1);
     });
   });
 
   describe('Data Operations', () => {
     beforeEach(() => {
-      db.exec(`
+      // Seed necessary data for these tests into the test database
+      testDb.exec(`
         INSERT INTO users (id) VALUES ('34650112233');
         INSERT INTO groups (id, community_id, name)
         VALUES ('test-group', 'test-community', 'Test Group')
@@ -109,7 +124,7 @@ describe('Database', () => {
     });
 
     test('should allow inserting group tasks', () => {
-      const result = db.prepare(`
+      const result = testDb.prepare(`
         INSERT INTO tasks (description, created_by, group_id)
         VALUES ('Test task', '34650112233', 'test-group')
       `).run();
@@ -117,7 +132,7 @@ describe('Database', () => {
     });
 
     test('should allow inserting private tasks', () => {
-      const result = db.prepare(`
+      const result = testDb.prepare(`
         INSERT INTO tasks (description, created_by)
         VALUES ('Private task', '34650112233')
       `).run();