feat(api): companion SSE turn endpoint + per-Space history

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tests/api/companion.test.js

@@ -0,0 +1,57 @@
+import { describe, it, expect, beforeAll } from 'vitest';
+import request from 'supertest';
+import { pool } from '../../lib/db/pool.js';
+import { createApp } from '../../server.js';
+import { resetDb } from '../helpers/db.js';
+import { migrateUp } from '../../lib/db/migrate.js';
+
+let app, spaceId;
+beforeAll(async () => {
+  await resetDb(); await migrateUp();
+  process.env.OWNER_TOKEN = 'test-token';
+  ({ rows: [{ id: spaceId }] } = await pool.query(
+    `INSERT INTO spaces(slug,name) VALUES('s','S') RETURNING id`));
+  app = createApp();
+  let step = 0;
+  app.locals.callModel = async ({ onTextDelta }) => {
+    if (step++ === 0) return { text: '', toolUses: [{ id: 't1', name: 'propose_change',
+      input: { entity_type: 'task', action: 'create', payload: { space_id: spaceId, title: 'Validate CSV' } } }], stopReason: 'tool_use', usage: {} };
+    for (const ch of 'Drafted a task.') onTextDelta?.(ch);
+    return { text: 'Drafted a task.', toolUses: [], stopReason: 'end_turn', usage: { output_tokens: 3 } };
+  };
+});
+
+const auth = (r) => r.set('Authorization', 'Bearer test-token');
+
+describe('companion API', () => {
+  it('GET creates the conversation and returns empty history', async () => {
+    const res = await auth(request(app).get(`/api/spaces/${spaceId}/companion`));
+    expect(res.status).toBe(200);
+    expect(res.body.conversation_id).toBeTruthy();
+    expect(res.body.messages).toEqual([]);
+  });
+
+  it('POST /turn streams SSE events and persists messages + draft', async () => {
+    const res = await auth(request(app).post(`/api/spaces/${spaceId}/companion/turn`))
+      .send({ text: 'make a task to validate the CSV' });
+    expect(res.status).toBe(200);
+    expect(res.headers['content-type']).toMatch(/text\/event-stream/);
+    expect(res.text).toMatch(/event: tool/);
+    expect(res.text).toMatch(/event: draft/);
+    expect(res.text).toMatch(/event: delta/);
+    expect(res.text).toMatch(/event: done/);
+
+    const { rows: msgs } = await pool.query(
+      `SELECT role, body, metadata FROM messages ORDER BY created_at`);
+    expect(msgs.map(m => m.role)).toEqual(['user', 'assistant']);
+    expect(msgs[1].body).toBe('Drafted a task.');
+    expect(msgs[1].metadata.draft_ids).toHaveLength(1);
+
+    const { rows: pc } = await pool.query(`SELECT * FROM pending_changes`);
+    expect(pc).toHaveLength(1);
+    expect(pc[0].status).toBe('pending');
+
+    const { rows: tasks } = await pool.query(`SELECT * FROM tasks WHERE title='Validate CSV'`);
+    expect(tasks).toHaveLength(0); // draft only, not applied
+  });
+});