File Analysis: convex/aiTown/inputHandler.ts

This file provides a foundational utility function, inputHandler, that acts as a standardized “template” or “blueprint” for creating all game input actions. It is a simple but powerful tool for ensuring code consistency and type safety.

1. Core Role and Positioning

This file’s role is to ensure that all input definitions across the project are uniform and predictable. It doesn’t execute any game logic itself but instead enforces a consistent structure for defining how the system should process inputs like player movements or chat messages.

2. Core Value and Process

The core value of this file is to enforce a clean design pattern. By using the inputHandler function, developers can define new actions in a structured way that guarantees every action clearly specifies the arguments it expects and the logic it will execute. This greatly improves code maintainability and reduces errors.

The process of using this utility is a definitional one, not a runtime one:

3. Code Deep Dive

Function: inputHandler(def)

Logic Explained: This file defines a single, crucial utility function: inputHandler. It’s not a function that performs a game action directly, but rather a “factory” or “template” for creating other functions that do.

When a developer wants to create a new action for the game (like moving a character), they must use this inputHandler function. It requires them to provide a configuration object, def, which must contain two specific things:

1. args: A set of rules that define what information the action needs, using the Convex framework’s validation system to ensure data correctness.
2. handler: The actual code that performs the action, which is given the current game state and the validated args.

The inputHandler function itself is surprisingly simple: it just returns the def object it was given. Its real power is in its TypeScript type signature, which enforces at compile-time that the developer has provided both args and handler correctly. This creates a consistent and predictable pattern for all game inputs, making the system easier to manage and debug.

import { ObjectType, PropertyValidators, Value } from 'convex/values';
import type { Game } from './game';
 
export function inputHandler<ArgsValidator extends PropertyValidators, Return extends Value>(def: {
  args: ArgsValidator;
  handler: (game: Game, now: number, args: ObjectType<ArgsValidator>) => Return;
}) {
  return def;
}