fix: write findings to review dir

app/comments.test.js

@@ -0,0 +1,22 @@
+import { describe, it } from 'node:test';
+import assert from 'node:assert/strict';
+import fs from 'fs';
+import os from 'os';
+import path from 'path';
+import { saveFindings } from './comments.js';
+import { FINDINGS_PATH } from './config.js';
+
+describe('saveFindings', () => {
+  it('writes findings to workspace and mirror dirs when provided', () => {
+    const workspace = fs.mkdtempSync(path.join(os.tmpdir(), 'findings-ws-'));
+    const mirrorDir = fs.mkdtempSync(path.join(os.tmpdir(), 'findings-mirror-'));
+    const findings = [{ level: 'warning', role: 'Leo', location: 'file.js:1', suggestion: 'test' }];
+
+    saveFindings(workspace, findings, mirrorDir);
+
+    const workspaceText = fs.readFileSync(path.join(workspace, FINDINGS_PATH), 'utf8');
+    const mirrorText = fs.readFileSync(path.join(mirrorDir, FINDINGS_PATH), 'utf8');
+    assert.equal(workspaceText, JSON.stringify(findings, null, 2) + '\n');
+    assert.equal(mirrorText, JSON.stringify(findings, null, 2) + '\n');
+  });
+});