Typescript multiple sequential awaits not blocking

Question

I'm trying to figure out how to get multiple back-to-back await calls to occur in sequential order. Here's my setup:

• typescript 2.5.2
  • transpiling to es5
  • using libs es2017 and dom in tsconfig
• node.js 8.6
• deploying to a docker container running in minikube 0.22.2

Here's the problem code. It's running a query against postgresql using the node pg package. I based it off of the example code https://node-postgres.com/features/transactions#a-pooled-client-with-async-await.

import { Client, Pool } from 'pg';

// An existing client connection can be passed in so that the calling code
// can manage a transaction. If none is provided, a new connection is
// retrieved from the connection pool.
async function query(
  connPool: Pool,
  querystr: string,
  params: (number | string)[],
  client?: Client
): Promise<any[]> {
  let result;
  let conn: Client = client;
  if (conn) {
    result = await conn.query(querystr, params);
  }
  else {
    conn = await connPool.connect();
    result = await conn.query(querystr, params);
    conn.release();
  }
  return result.rows;
}

And I'm calling the query() funtion from another file, like so:

const results = await query(myPool, 'SELECT * FROM my_table');
doOtherThing(results);

Based on every source code example I've seen, I expect it to behave this way:

• call made to query()
• line conn = await connPool.connect(); blocks until a connection is retrieved from the pool
• line result = await conn.query(querystr, params); blocks until the results of the query are retrieved
• line return result.rows; returns results to the calling code
• the calling code receives the records from the database
• doOtherThing() is called

However, it's executing in this order:

• call made to query()
• line conn = await connPool.connect(); returns immediately
• the calling code receives undefined in results
• doOtherThing() is called
• line result = await conn.query(querystr, params); returns immediately, to nowhere
• line return result.rows; results are returned to nowhere

Any guidance on what I'm doing wrong? Am I completely misguided on the right way to use async/await?

Answer 1

I found the problem. The expected behavior laid out in the question is correct.

In between the statement const results = await query(myPool, 'SELECT * FROM my_table'); and the actual function was another function with the same name query(). This other function acted as a pass-through to the implementation of the query() function that I included in the original post. This function in the middle didn't return anything, which caused the unexpected behavior.