Implicit Argument to JavaScript Promise

I came across some code at work that I did not understand. After doing a little digging, I learned something I did not know about Promises. If you have a single argument to a function, you can use an implicit argument. What does the mean? Let's start with an example:

test(0)
 .then((results) => test(results))
 .then((results) => test(results))
 .then((results) => { console.log(`Results from first test: ${results}`) });

function test(arg) {
 return new Promise((resolve, reject) => {
  resolve(arg + 1);
 });
}

So what's happening here? I am passing the number zero to the function test. It is taking that number, adding one to it, and returning a new Promise. .then((results) => test(results) then takes that result and passes it to the test function again which again adds one and returns a new Promise. Finally, we are printing the result which is 3. Now here is a different way to write that code with an implicit argument:

test(0)
 .then(test)
 .then(test)
 .then(results => { console.log(`Results from second test: ${results}`) });

function test(arg) {
 return new Promise((resolve, reject) => {
  resolve(arg + 1);
 });
}

The result is the same. In this case, .then(test) is the equivalent of .then((results) => test(results)). This shorthand notation only works for a single argument. If you have multiple arguments to your function, you will have to write out the full code.

MySQL Subqueries

For most of my software development career, I used an Oracle database. At my current job, we use a MySQL database. So I am still learning the ins and outs of MySQL. Here is a common thing I would do in Oracle:

SELECT
  name, total_points
FROM (
  SELECT
    name,
    SUM(points) AS total_points
  FROM
    scores
  GROUP BY
    name
)
WHERE
  total_points >  10
ORDER BY
  total_points DESC, name

That would give me a list of all players who have scored more than 10 points. When I tried this same format in MySQL, I got this error:

Error Code: 1248. Every derived table must have its own alias

After a little searching, I came up with the solution. I had to name my inner query. So with a slight modification it worked:

SELECT
  tp.name, tp.total_points
FROM (
  SELECT
    name,
    SUM(points) AS total_points
  FROM
    scores
  GROUP BY
    name
) tp
WHERE
  total_points >  10
ORDER BY
  total_points DESC, name

Accessibility and Social Media Management

There is a local radio program that I used to listen to that gives advice on yards and gardening. The host is very knowledgeable and is my go-to resource when I have questions about planting, fertilizing, and weeding. Here was an exchange this morning between (presumably) the social media manager for his account and one of his followers regarding a video that was posted:

The follower asked a simple question but got back a seemingly harsh response. First, let's look at why the follower may have misunderstood the audio.

• · Maybe the follower is hard of hearing
• · Maybe the follower's native language in not English
• · Maybe the follower was in a noisy environment
• · Maybe all of the above are true

The response from the author did not take any of these things into account. That is why accessibility is important not just for us web developers but for content providers as well. A better response might have been:

Thank you for your question. He was saying "rose soil". Here is an example of a product that we recommend.

Here is another thing to consider. Various sites such as this one report that 85% of Facebook videos are watched without sound! Additionally the World Health Organization reports that globally over 400 million people suffering from some sort of hearing loss. So if you are relying solely on audio on your site to get your message across, you are alienating a large group of people. This is why it is so important to provide captioning on your social media videos.

I realize that not everyone will have the skills, times, and/or technology to caption their videos. So in that case, a good fallback plan when someone poses a questions about the audio is to just be kind.