import { describe, it } from 'node:test';
import assert from 'node:assert';
describe('connection lock pattern', () => {
it('should prevent concurrent connection attempts', async () => {
let connectCalls = 0;
let connecting: Promise<boolean> | null = null;
// Simulate slow connection
const connect = async (): Promise<boolean> => {
connectCalls++;
await new Promise((resolve) => setTimeout(resolve, 50));
return true;
};
// Same pattern used in index.ts
const tryConnect = async (): Promise<boolean> => {
if (connecting) return connecting;
connecting = connect();
try {
return await connecting;
} finally {
connecting = null;
}
};
// Call concurrently
const [result1, result2, result3] = await Promise.all([
tryConnect(),
tryConnect(),
tryConnect(),
]);
assert.strictEqual(result1, true);
assert.strictEqual(result2, true);
assert.strictEqual(result3, true);
assert.strictEqual(connectCalls, 1, 'connect should only be called once');
});
it('should allow new connection after previous completes', async () => {
let connectCalls = 0;
let connecting: Promise<boolean> | null = null;
const connect = async (): Promise<boolean> => {
connectCalls++;
return true;
};
const tryConnect = async (): Promise<boolean> => {
if (connecting) return connecting;
connecting = connect();
try {
return await connecting;
} finally {
connecting = null;
}
};
await tryConnect();
await tryConnect();
assert.strictEqual(connectCalls, 2, 'sequential calls should each connect');
});
it('should propagate errors to all waiters', async () => {
let connecting: Promise<boolean> | null = null;
const connect = async (): Promise<boolean> => {
await new Promise((resolve) => setTimeout(resolve, 10));
throw new Error('connection failed');
};
const tryConnect = async (): Promise<boolean> => {
if (connecting) return connecting;
connecting = connect();
try {
return await connecting;
} finally {
connecting = null;
}
};
const results = await Promise.allSettled([
tryConnect(),
tryConnect(),
]);
assert.strictEqual(results[0].status, 'rejected');
assert.strictEqual(results[1].status, 'rejected');
});
});
