'Promise on a server-side script (User Event) executing synchronously?

If I understood the Promise behavior correctly, it's used so that anything inside the custom Promise will be executed asynchronously.I did a test user event script and found out that it's executed synchronously.

My sample code below:

/**
 * @NApiVersion 2.1
 * @NScriptType UserEventScript
 */
define(['N/runtime', 'N/https', 'N/url'], function (runtime, https, url) {

    function beforeLoad(context) {
        try {
            log.debug({ title: 'promise 1 start', details: new Date() });
            let promise1 = new Promise((resolve) => {
                let response = https.requestRestlet({
                    headers: { 'Content-Type': 'application/json' },
                    scriptId: 'customscript_test_rl',
                    deploymentId: 'customdeploy_test_rl',
                    body: JSON.stringify({ foo: 'bar' })
                });
                // resolve(response.body);
                log.debug({ title: 'response1', details: response });
            });
            log.debug({ title: 'promise 1 end', details: new Date() });
            log.debug({ title: 'promise 2 start', details: new Date() });
            let promise2 = new Promise((resolve) => {
                let response = https.requestRestlet({
                    headers: { 'Content-Type': 'application/json' },
                    scriptId: 'customscript_test_rl',
                    deploymentId: 'customdeploy_test_rl',
                    body: JSON.stringify({ foo: 'bar' })
                });
                // resolve(response.body);
                log.debug({ title: 'response2', details: response });
            });
            log.debug({ title: 'promise 2 end', details: new Date() });
        } catch (ex) {
            log.debug({ title: ex.name, details: ex });
        }
    }

    return {
        beforeLoad: beforeLoad
    };
});

Am I doing something wrong or am I wrong about the behavior of a promise?

promisenetsuitesuitescript2.0


Solution 1:[1]

Am I wrong about the behavior of a promise?

Yes, you are wrong. The promise executor function is executed synchronously. You don't use a promise to make something that is naturally synchronous into an asynchronous operation. It doesn't do that.

A promise is a notification mechanism for managing and communicating the completion of an operation that is already asynchronous. It doesn't make anything asynchronous that wasn't already asynchronous.

Sources

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Source: Stack Overflow

Solution Source
Solution 1 jfriend00

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