A swiss army knife for development tooling in Foundry VTT.

• Provides a UI to toggle any Foundry Core CONFIG.debug flags, persisting the selection in the user's client settings.
• Provides an API to register and read a "debug mode flag" which is either a boolean or a number from 0 to 5 (log level).
• Provides a UI to toggle these flags on and off, preserving this selection in the user's client settings.
• Provides a button to copy and print documents to console.
• Provides some utilities to detect JSON configuration changes or errors.
• Allows developer to disable the template cache for a "poor man's hot reload" for handlebars files.

Enable developers to stop putting debug code in their module code which accidentally gets shipped. Empower developers with commonly sought-after QOL features.

1. Leverage the potential future CONFIG.debug.moduleDebug flag.
2. Implement other developer tooling. Have an idea? Leave a suggestion!

Module JSON:

https://github.com/League-of-Foundry-Developers/foundryvtt-devMode/releases/latest/download/module.json

While active, after the hook devModeReady is fired, the following api methods are expected to be on game.modules.get('_dev-mode')?.api:

async registerPackageDebugFlag(
  packageName: string,
  kind?: 'boolean' | 'level',
  options?: {
    default?: boolean | LogLevel;
    choiceLabelOverrides?: Record<number, string>;
  }
): Promise<boolean>

• kind defaults to 'boolean'
• options.default is either false or 0 by default, depending on the kind
• options.choiceLabelOverrides allows an object to be passed which overrides the choice labels for a given level (0 - 5). The provided string will be run through localize.
• Returns a promise which resolves true or false depending on if successful.

registerPackageDebugFlag('my-module-id', 'level', {
  choiceLabelOverrides: {
    0: 'Foo',
    1: 'Bar',
    2: 'Bat',
    3: 'Biz',
    4: 'Bin',
    5: 'Bam',
  },
});

getPackageDebugValue(
  packageName: string,
  kind?: 'boolean' | 'level',
): boolean | LogLevel

• kind defaults to 'boolean'
• Returns the current value of your debug flag

If all you want is a simple boolean, this is as simple as doing this in your module's js:

Hooks.once('devModeReady', ({ registerPackageDebugFlag }) => {
  registerPackageDebugFlag('my-module-id');
});

Here's a log function I use which allows me to toggle on all of the stupid little logs I leave all over the place while I'm debugging.

const MODULE_ID = 'my-module-id';

function log(force: boolean, ...args) {
  try {
    const isDebugging = game.modules.get('_dev-mode')?.api?.getPackageDebugValue(MODULE_ID);

    if (force || isDebugging) {
      console.log(MODULE_ID, '|', ...args);
    }
  } catch (e) {}
}

// ...

log(false, someVarToLog); // won't log unless my debug value is true

• Any module which adds a custom key to CONFIG.debug will have that key show up in the CONFIG.debug overrides setting section.

This is an example typescript definition which would be accurate for the DevMode API available on game.modules.get('_dev-mode')?.api and provided as the argument to devModeReady's callbacks.

enum LogLevel {
  NONE = 0,
  INFO = 1,
  ERROR = 2,
  DEBUG = 3,
  WARN = 4,
  ALL = 5,
}

interface DevModeApi {
  registerPackageDebugFlag(packageName: string, kind?: "boolean" | "level", options?: {
      default?: boolean | LogLevel;
      choiceLabelOverrides?: Record<string, string>; // actually keyed by LogLevel number
  }): Promise<boolean>;

  getPackageDebugValue(packageName: string, kind?: "boolean" | "level"): boolean | LogLevel;
}

Mad props to the League of Extraordinary FoundryVTT Developers community which helped me figure out a lot.

Bootstrapped with Ghost's Foundry Factory then heavily trimmed.