import { test } from 'node:test';
import assert from 'node:assert/strict';
import { IsolateRunner, FunctionError } from '../src/runtime/isolate.js';

test('passes event through a noop transform', async () => {
  const r = new IsolateRunner({ memoryLimitMB: 64, timeoutMs: 1000 });
  const code = `
    function transform(event) {
      return event;
    }
  `;
  const got = await r.run(code, { message_id: 'm1', type: 'track' });
  assert.equal(got.message_id, 'm1');
});

test('mutates event properties', async () => {
  const r = new IsolateRunner({ memoryLimitMB: 64, timeoutMs: 1000 });
  const code = `
    function transform(event) {
      event.properties = event.properties || {};
      event.properties.tagged = true;
      return event;
    }
  `;
  const got = await r.run(code, { message_id: 'm1', type: 'track' });
  assert.equal(got.properties.tagged, true);
});

test('returns null to drop event', async () => {
  const r = new IsolateRunner({ memoryLimitMB: 64, timeoutMs: 1000 });
  const code = `function transform(event) { return null; }`;
  const got = await r.run(code, { message_id: 'm1', type: 'track' });
  assert.equal(got, null);
});

test('rejects code without transform()', async () => {
  const r = new IsolateRunner({ memoryLimitMB: 64, timeoutMs: 1000 });
  await assert.rejects(
    () => r.run(`const x = 1;`, { message_id: 'm1', type: 'track' }),
    (err) => err instanceof FunctionError && err.kind === 'runtime',
  );
});

test('times out infinite loops', async () => {
  const r = new IsolateRunner({ memoryLimitMB: 64, timeoutMs: 100 });
  const code = `function transform(event) { while (true) {} return event; }`;
  await assert.rejects(
    () => r.run(code, { message_id: 'm1', type: 'track' }),
    (err) => err instanceof FunctionError && err.kind === 'timeout',
  );
});