A client came to us with their WooCommerce shop last week. The request seemed simple enough: add a tiered discount for VIP customers. But when my developer dug into the `functions.php` file, he found a monster. A huge, 1000-line function with no comments, no documentation, nothing. The original developer was long gone, and nobody knew what this beast did, only that it was somehow related to shipping calculations. Total nightmare.
This is a classic case of technical documentation debt. It’s the developer equivalent of writer’s block, but instead of a blank page, you’re staring at a tangled mess of code with zero context. And it costs clients real money.
Your Code’s “Why” Is More Important Than Its “How”
My first thought was to just reverse-engineer it. I told my dev, “Let’s just trace the logic and figure it out.” And yeah, that was a mistake. We burned three hours just trying to map out the function calls, and we still weren’t sure what all the variables were for. We were completely blocked. Here’s the kicker: we couldn’t confidently add the new feature without risking breaking the entire shipping calculator. For all we knew, there was some weird edge case for international shipping that our changes would destroy.
The real problem wasn’t the complexity of the code; it was the absence of its story. Why was it built this way? What specific problem was it solving? The previous developer never wrote it down. This is something I learned from a great post over at carlalexander.ca about overcoming writer’s block. The principle is the same: you have to know what you’re trying to say. With code, that means documenting your intent.
/**\n * Calculates custom shipping rates based on user role and cart weight.\n *\n * Business Logic: VIP members get a 50% discount on shipping for orders\n * under 10kg. This was a special request from marketing to boost the\n * loyalty program enrollment in Q4 2022.\n *\n * @param float $shipping_cost The original shipping cost.\n * @param int $cart_weight_kg The total weight of the cart in kilograms.\n * @return float The adjusted shipping cost.\n */\nfunction calculate_custom_vip_shipping( $shipping_cost, $cart_weight_kg ) {\n if ( ! is_user_logged_in() || $cart_weight_kg >= 10 ) {\n return $shipping_cost; // Exit early if not applicable.\n }\n\n $user = wp_get_current_user();\n if ( in_array( 'vip_customer', (array) $user->roles ) ) {\n // Here's the kicker: apply the 50% discount.\n $shipping_cost *= 0.5;\n }\n\n return $shipping_cost;\n}So, What’s the Point?
Writing good technical documentation isn’t about being a novelist. It’s about being a professional. It’s about saving the next person (and often, your future self) from hours of frustration. Before you write a single line of a new feature, you should be able to answer these questions:
- What problem is this solving?
- Are there any weird business rules I need to account for?
- How does this function fit into the bigger picture?
Answering them in a comment block or a `README` file takes maybe 15 minutes. That’s it. Trust me on this, that 15 minutes can save thousands of dollars and weeks of delays down the road.
Look, this stuff gets complicated fast. If you’re tired of debugging someone else’s mess and just want your site to work, drop my team a line. We’ve probably seen it before.
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