Let's assume that we've identified a bottleneck in our code base, and it happens to be a function called divideByAndSum. A hypothetical flamegraph has revealed that this function is appearing over 10% of the time at stack-top over multiple samples.
The function looks like this:
function divideByAndSum (num, array) { try { array.map(function (item) { return item / num }).reduce(function (acc, item) { return acc + item }, 0) } catch (err) { // to guard for division by zero return 0 }}
Our task now is to make this function faster.
The first step is to extract that function into its own module.
Let's create a file called slow.js:
function divideByAndSum (num, array) { try { array.map(function (item) { return item / num }).reduce(function ...
