feat(telemetry): TelemetryService.emit with KST rotation (#7 v0.2.3)

tests/unit/TelemetryService.test.ts

@@ -0,0 +1,74 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { mkdtempSync, rmSync, readFileSync, existsSync, readdirSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+import { TelemetryService } from '@main/services/TelemetryService.js';
+
+describe('TelemetryService.emit', () => {
+  let dir: string;
+
+  beforeEach(() => { dir = mkdtempSync(join(tmpdir(), 'inkling-telem-')); });
+  afterEach(() => { rmSync(dir, { recursive: true, force: true }); });
+
+  it('appends a JSONL line to events-YYYY-MM-DD.jsonl (KST date)', async () => {
+    // 2026-05-01 12:00 UTC → 2026-05-01 21:00 KST
+    const svc = new TelemetryService(dir, () => new Date('2026-05-01T12:00:00Z'));
+    await svc.emit({ kind: 'capture', payload: { noteId: 'n1', rawTextLength: 5, hasMedia: false } });
+    const file = join(dir, 'events-2026-05-01.jsonl');
+    expect(existsSync(file)).toBe(true);
+    const content = readFileSync(file, 'utf8').trim();
+    const parsed = JSON.parse(content);
+    expect(parsed.kind).toBe('capture');
+    expect(parsed.payload.noteId).toBe('n1');
+    expect(typeof parsed.ts).toBe('string');
+  });
+
+  it('uses KST date even when UTC date differs (around midnight)', async () => {
+    // 2026-05-01 23:30 UTC → 2026-05-02 08:30 KST
+    const svc = new TelemetryService(dir, () => new Date('2026-05-01T23:30:00Z'));
+    await svc.emit({ kind: 'capture', payload: { noteId: 'n2', rawTextLength: 1, hasMedia: false } });
+    expect(existsSync(join(dir, 'events-2026-05-02.jsonl'))).toBe(true);
+  });
+
+  it('appends multiple events to same-day file', async () => {
+    const svc = new TelemetryService(dir, () => new Date('2026-05-01T12:00:00Z'));
+    await svc.emit({ kind: 'capture', payload: { noteId: 'n1', rawTextLength: 5, hasMedia: false } });
+    await svc.emit({ kind: 'ai_succeeded', payload: { noteId: 'n1', durationMs: 100, attempts: 0 } });
+    const lines = readFileSync(join(dir, 'events-2026-05-01.jsonl'), 'utf8').trim().split('\n');
+    expect(lines).toHaveLength(2);
+    expect(JSON.parse(lines[0]!).kind).toBe('capture');
+    expect(JSON.parse(lines[1]!).kind).toBe('ai_succeeded');
+  });
+
+  it('creates telemetry dir if absent', async () => {
+    const fresh = join(dir, 'nested', 'telem');
+    const svc = new TelemetryService(fresh, () => new Date('2026-05-01T12:00:00Z'));
+    await svc.emit({ kind: 'capture', payload: { noteId: 'n1', rawTextLength: 1, hasMedia: false } });
+    expect(existsSync(fresh)).toBe(true);
+  });
+
+  it('rejects malformed event (privacy invariant) — does NOT write file', async () => {
+    const svc = new TelemetryService(dir, () => new Date('2026-05-01T12:00:00Z'));
+    await expect(svc.emit({
+      kind: 'capture',
+      payload: { noteId: 'n1', rawTextLength: 1, hasMedia: false, rawText: 'leak' } as never
+    })).rejects.toThrow();
+    // No file should have been created
+    expect(readdirSync(dir).filter((f) => f.startsWith('events-'))).toEqual([]);
+  });
+
+  it('emit is silent (does not throw) when fs write fails — invariant: telemetry never breaks app', async () => {
+    // Pass a non-writable path; emit should swallow the error.
+    const svc = new TelemetryService(
+      '/proc/0/no-such-thing-readonly',
+      () => new Date('2026-05-01T12:00:00Z'),
+      14,
+      { silent: true }
+    );
+    // Should resolve, not throw
+    await expect(svc.emit({
+      kind: 'capture',
+      payload: { noteId: 'n1', rawTextLength: 1, hasMedia: false }
+    })).resolves.toBeUndefined();
+  });
+});