how could I reduce the cyclomatic complexity?

Question

Whenever I lint a piece of code I\'m working on I get the This function\'s cyclomatic complexity is too high. (7). But I\'m a bit confused on how I could rewrit

Answer 1

Well you have only two actions in your code, but much too many conditions. Use a single if-else-statement, and boolean operators in the condition. If that was impossible, you could at least

• remove the empty lines to get the full logic on one screen page
• add some comments on what the branches are doing (and why)
• avoid early returns

Here's your function simplified:

var duration = +new Date() - start.time,
    isPastHalf = Number(duration) < 250 && Math.abs(delta.x) > 20 || Math.abs(delta.x) > viewport / 2,
    isFarRight = this.content.getBoundingClientRect().left > viewport / 2, 
    direction = delta.x < 0;

if (!isScrolling) {
    if (isPastHalf) {
        if (direction)
            this.close();
        else {
            if (isFarRight && pulled)
                this.close();
            else
                this.open();
        }
    } else {
        if (isFarRight) {
            // Looks like the opposite of `direction`, is it?
            if (this.isEmpty(delta) || delta.x > 0)
                this.close();
            else
                this.open();
        } else
            this.close();
    }
}

and shortened:

var duration = +new Date() - start.time,
    isPastHalf = Number(duration) < 250 && Math.abs(delta.x) > 20 || Math.abs(delta.x) > viewport / 2,
    isFarRight = this.content.getBoundingClientRect().left > viewport / 2, 
    direction = delta.x < 0,
    undirection = this.isEmpty(delta) || delta.x > 0;

if (!isScrolling) {
    if ( isPastHalf && !  direction && !(isFarRight && pulled)
     || !isPastHalf && !undirection &&  isFarRight )
        this.open();
    else
        this.close();
}