test: specify memory graph query APIs

tests/identity-db.test.ts

@@ -0,0 +1,54 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest';
+
+import { IdentityDB } from '../src/core/identity-db';
+
+describe('IdentityDB topic and fact writes', () => {
+  let db: IdentityDB;
+
+  beforeEach(async () => {
+    db = await IdentityDB.connect({ client: 'sqlite', filename: ':memory:' });
+    await db.initialize();
+  });
+
+  afterEach(async () => {
+    await db.close();
+  });
+
+  it('deduplicates topics by normalized name during upsert', async () => {
+    const first = await db.upsertTopic({
+      name: 'TypeScript',
+      category: 'entity',
+      granularity: 'concrete',
+    });
+
+    const second = await db.upsertTopic({
+      name: '  typescript  ',
+      category: 'entity',
+      granularity: 'concrete',
+    });
+
+    expect(second.id).toBe(first.id);
+    expect(second.normalizedName).toBe('typescript');
+
+    const topics = await db.listTopics({ includeFacts: false });
+    expect(topics).toHaveLength(1);
+  });
+
+  it('adds one fact that links multiple topics', async () => {
+    const fact = await db.addFact({
+      statement: 'I have worked with TypeScript since 2025.',
+      topics: [
+        { name: 'I', category: 'entity', granularity: 'concrete', role: 'subject' },
+        { name: 'TypeScript', category: 'entity', granularity: 'concrete', role: 'object' },
+        { name: '2025', category: 'temporal', granularity: 'concrete', role: 'time' },
+      ],
+    });
+
+    expect(fact.statement).toBe('I have worked with TypeScript since 2025.');
+    expect(fact.topics.map((topic) => topic.name)).toEqual(['I', 'TypeScript', '2025']);
+
+    const typeScriptFacts = await db.getTopicFacts('TypeScript');
+    expect(typeScriptFacts).toHaveLength(1);
+    expect(typeScriptFacts[0]?.statement).toBe('I have worked with TypeScript since 2025.');
+  });
+});