Runtime Declarations

Runtime type declarations in Spinorium allow you to extend and customize the engine's interfaces and types. This is done through declaration merging, a TypeScript feature that lets you add new properties to existing types.

Understanding runtime.d.ts

The runtime.d.ts file is a TypeScript declaration file, usually located in the source folder of the project. Using this file provides several benefits:

• Eliminates excessive type casting throughout the codebase.
• Enables overriding of existing interfaces from the engine.
• Maintains type safety for custom game-specific controllers and models.
• Defines game-specific data structures.

Usage Example

import { GameController } from './controller/GameController';
import { GamePlayerModel } from './controller/GamePlayerModel';
import { GameRoundModel } from './controller/GameRoundModel';
import { GameRoundState } from './controller/GameRoundState';

declare module '@spinorium/engine' {
    interface SystemContext {
        readonly model:GamePlayerModel;
        readonly controller:GameController;
        readonly state:Readonly<GameRoundState>;
        readonly round:GameRoundModel;
    }

    interface ISymbolState {
        upgradeLevel?:number;
    }
}

In the example above:

• The SystemContext interface is extended to include core game-specific properties. These are accessible through the System global constant (e.g., System.round.roundBet).

• The ISymbolState interface is enhanced with a new property upgradeLevel. This enables type-safe usage of the property across the game code without the need for manual casting.

const symbol = slotMachine.factory.compose({
    // Property now available and type-safe
    upgradeLevel: 1,
    index: SymbolType.HP_1,
    sourceType: SymbolSourceType.REAL,
    stateType: 'idle'
});

// Property now available and type-safe
// You'll see "1" in the console
console.log(symbol.state.upgradeLevel);