Error: Queue is Empty

[camfeghali]

I'm running tests using jest, jest-postgres, to spin up a local postgres instance, and using ts-postgres to access that postgres instance.

Tests are failing with the following error:

    Cannot log after tests are done. Did you forget to wait for something async in your test?
    Attempted to log "ts-postgres: Error: Queue is empty".

      at console.warn (../../../node_modules/@jest/console/build/BufferedConsole.js:191:10)
      at log (../../../node_modules/ts-postgres/src/logging.ts:7:16)
      at Object.warn (../../../node_modules/ts-postgres/src/logging.ts:19:13)
      at Socket.<anonymous> (../../../node_modules/ts-postgres/src/client.ts:386:24)

This is the code that executes when making queries:

  async function connection() {
    if (!client || client.closed) {
      client = new Client(config);
      await client.connect();
      return client;
    }
    return client;
  }
  async function query<T>(query: string): Promise<T[]> {
    try {
      const conn = await connection();
      const queryResult = await conn.query(query);
      const { rows, names } = queryResult;
      return rows.map((row) => mapToObj<T>(row, names));
    }
  }

And this is how I use it

export async function get(props) {
    const { schema, tableName } = DB_CONFIG;
    const whereClause = buildWhereClause(props);
    const query = `SELECT * from ${schema}.${tableName} ${whereClause};`;
    const pgClient = postgresClient(DB_CONFIG);

    return await pgClient.query<RecommendableProduct>(query);
}

Am I missing something? Any help would be much appreciated!

[malthe]

Can you try to do await pgClient.connect() first – just to see if it's failing during the initial connection?

[camfeghali]

hey @malthe , thanks for getting back to me. Maybe I should've shared this from the start.

I created a small wrapper around ts-postgres like so:

export default function postgresClient(config: PostgresConfig) {
  let client: Client | undefined;

  const { schema, tableName } = config;

  async function connection() {
    if (!client || client.closed) {
      client = new Client({ ...config, keepAlive: false });
      await client.connect();
      return client;
    }
    return client;
  }
  async function query<T>(query: string): Promise<T[]> {
    const conn = await connection();
    try {
      const queryResult = await conn.query(query);
      const { rows, names } = queryResult;
      return rows.map((row) => mapToObj<T>(row, names));
    } 
  }

  return { query };
 }

With which I then run:

export async function get(props) {
    const { schema, tableName } = DB_CONFIG;
    const whereClause = buildWhereClause(props);
    const query = `SELECT * from ${schema}.${tableName} ${whereClause};`;
    const pgClient = postgresClient(DB_CONFIG);

    return await pgClient.query<RecommendableProduct>(query);
}

Are you suggesting I return a promise which resolves to { query };

[malthe]

What does a try { } block without catch/finally do?

[camfeghali]

nothing, I omitted the catch/finally to avoid clutter. It's actually this:

  async function query<T>(query: string): Promise<T[]> {
    const conn = await connection();
    try {
      const queryResult = await conn.query(query);
      const { rows, names } = queryResult;
      return rows.map((row) => mapToObj<T>(row, names));
    } catch (error) {
      if (error instanceof Error) {
        log.error({ message: error.message, payload: query });
        throw error;
      } else {
        log.error({ message: 'Postgres Query Error.', query: query });
        throw new Error('Something went wrong Querying postgres.');
      }
    }
  }

[camfeghali]

for more info. If I conn.end() in the finally, ts-postgres does not log when running a single test. But throws Already ending when running my test suite.

[malthe]

I suspect this is a connectivity problem based on the fact that you're incorporating this jest-postgres system – but of course we shouldn't see this error, we should see something we can understand.

[camfeghali]

@malthe I figured it out. in the beforeAll() block of my tests, I was running a await Promise.all(arr.map(x => await query('insert ...'))), I changed it to build the whole query and do a single insert to the DB, removing parallel queries. Thanks for helping!

[malthe]

Hard to say what the underlying problem was, but it could be that there are just some strange parallelism problem in the way you're writing the code.

But I don't like that error message "ts-postgres: Error: Queue is empty" – that suggests that it's possible to use the client in a way that's not intended, something that the client should be able to figure out and prevent you from doing.

However, unless you have a setup I can try out locally, it's hard to continue on it ...