In Defense of Positive Logic over Happy Path

bepositive.php

<?php

/**
 * Option 1: Happy Path (! $this) 
 */

// 1. The world begins.

if (! $this) {
    $result = 'No complaints. This is easy to understand and follow.';
}

// 2. As time goes on, it is not unusual to add conditions...

if (! $this) {
    $result = 'Later, an else is added and IF NOT $this ELSE $that is not intuitive.';
} else {
    $result = 'But, rarely do developers rearrange an IF statement to add a condition.'; 
}

// 3. NOTs and ORs are toxic, buggy, unintuitive

if (! $this || $that) {
    $result = 'As with most logic, conditions grow in complexity until finally refactoring occurs.';
    $result .= 'Now what started as a simple if NOT is confusing, not at all intuitive. ';
    $result .= 'Did the dev intend to code if this is false or that is true? ';
    $result .= 'Or, was the intention that if either was false?';
    $result .= 'Combining nots and ors is difficult logic to follow, easy to create a bug.'; 
}

/**
 * Option 2: Positive Path -- IF $this THEN that 
 */

// 1. Starts

if ($this) {
} else {
    $result = 'Annoying to those taught "happy path" but otherwise easy to understand.';
}

// 2. 2nd Condition added

if ($this) {
    $result = 'See how easily the second condition slides in?';
} else {
    $result = 'This code does not change and it is still intuitive.';
}

// 3. Positive logic avoids NOTs and ORs which are very difficult to follow

if ($this && $that) {
} else {
    $result = 'Oh. I guess they meant if either this or that are false. Why not say so?';
    $result .= 'Throughout the evolution of the code, the structure and flow never changed.';
}