Hooks

Specify custom build logic with asynchronous callback functions

In Electron Forge, hooks are asynchronous callback functions that allow you to insert your own logic at different points in the development or build process.

Each hook function comes with the Forge configuration object as a first parameter.

Any writes to stdout and stderr from within a hook function will be printed in the console after the Forge build completes, and will only be visible with the DEBUG or CI environment variables set to some truthy value.

To read more about the different stages in Forge's build process, please refer to the Build Lifecycle documentation.

Simple hooks

In Electron Forge, most hooks are simple hooks, which perform side effects during the build lifecycle without directly affecting subsequent steps in the build.

generateAssets

• Arguments:

  • config:ResolvedForgeConfig - Forge configuration object

  • platform: string - Operating system platform

  • arch: string - CPU architecture

• Returns: Promise<void>

generateAssets() is invoked before Forge's start or package commands.

You can use this hook to generate any static files or resources your app requires on runtime but aren't in the source code.

For instance, you could use this hook to generate a license file containing the license of all your dependencies.

preStart

• Arguments:

  • config:ResolvedForgeConfig - Forge configuration object

• Returns: Promise<void>

preStart() is invoked before Forge's start command launches the app in dev mode.

You can use this hook to run prepatory logic before your app launches.

forge.config.js

module.exports = {
  hooks: {
    preStart: async (forgeConfig) => {
      console.log(`Starting up app on platform: ${process.platform}`);
    }
  }
};

postStart

• Arguments:

  • config:ResolvedForgeConfig - Forge configuration object

  • appProcess:ChildProcess - Node.js child process instance

• Returns: Promise<void>

postStart() is called after Forge's start command launches the app in dev mode.

You can use this hook to attach listeners to the spawned child process.

forge.config.js

module.exports = {
  hooks: {
    postStart: async (forgeConfig, appProcess) => {
      console.log(`Spawned child pid: ${appProcess.pid}`);
    }
  }
};

prePackage

• Arguments:

  • config:ResolvedForgeConfig - Forge configuration object

  • platform: string - Operating system platform

  • arch: string - CPU architecture

• Returns: Promise<void>

prePackage() is called before Forge runs Electron Packager in the package step .

packageAfterCopy

• Arguments:

  • config:ResolvedForgeConfig - Forge configuration object

  • buildPath: string- the app's temporary folder path

  • electronVersion: string- the app's Electron version

  • platform: string - Operating system platform

  • arch: string - CPU architecture

• Returns: Promise<void>

packageAfterCopy() is called inside the afterCopy hook of Electron Packager.

During Forge's package step, Electron Packager copies your app's build directory to a temporary folder.

The afterCopy hook runs after this copy step.

packageAfterPrune

• Arguments:

  • config:ResolvedForgeConfig- Forge configuration object

  • buildPath: string- the app's temporary folder path

  • electronVersion: string- the app's Electron version

  • platform: string - Operating system platform

  • arch: string - CPU architecture

• Returns: Promise<void>

packageAfterPrune() is called inside the afterPrune hook of Electron Packager.

During Forge's package step, Electron Packager prunes non-production node_modules dependencies from the temporary folder your app is copied to. This step minimizes the size of your app's production bundle.

The afterPrune hook runs after this prune step.

packageAfterPrune() will have no effect if your packagerOptions.prune option is set to false.

packageAfterExtract

• Arguments:

  • config:ResolvedForgeConfig- Forge configuration object

  • buildPath: string- the Electron binary's temporary folder path

  • electronVersion: string- the app's Electron version

  • platform: string - Operating system platform

  • arch: string - CPU architecture

• Returns: Promise<void>

packageAfterExtract() is called inside the afterExtract hook of Electron Packager.

During Forge's package step, Electron Packager extracts your Electron binary into a temporary folder.

The afterExtract hook runs after this extract step.

postPackage

• Arguments:

  • config:ResolvedForgeConfig- Forge configuration object

  • packageResult: Object

    • platform: string - Operating system platform

    • arch: string - CPU architecture

    • outputPaths: string[] - filesystem paths for package output

• Returns: Promise<void>

postPackage() is called after Forge's package step has successfully completed.

For example:

forge.config.js

module.exports = {
  hooks: {
    postPackage: async (forgeConfig, options) => {
      console.info('Packages built at:', options.outputPaths);
    }
  }
};

preMake

• Arguments:

  • config:ResolvedForgeConfig- Forge configuration object

• Returns: Promise<void>

preMake() is called before the make step runs.

Mutating hooks

In Electron Forge, mutating hooks are a special kind of hook that return the same type of value as their second parameter.

The returned value will replace the original parameter's value for subsequent steps in the Forge lifecycle.

postMake

• Arguments:

  • config:ResolvedForgeConfig- Forge configuration object

  • makeResults:MakeResult[]

• Returns: Promise<MakeResult[] | void>

postMake()is called after Forge's make step has successfully completed.

It is passed an array of MakeResult objects that are output from the make step. If you wish to mutate the array of Make results, you can return a new array of MakeResult objects that Electron Forge can use for future steps.

readPackageJson

• Arguments:

  • config:ResolvedForgeConfig- Forge configuration object

  • packageJson: Record<string, unknown> - Full package.json object

• Returns: Promise<Record<string, unknown> | void>

readPackageJson() is called every time Forge attempts to read your package.json file.

The full package.json object is passed in as a parameter. If you want to modify that object in any way, you must do so and return the new value for Forge to use.

This is useful to set things like the package.json version field at runtime.

forge.config.js

module.exports = {
  hooks: {
    readPackageJson: async (forgeConfig, packageJson) => {
      packageJson.version = '4.0.0';
      return packageJson;
    }
  }
};

Note: this hook will not change the name or version used by Electron Packager to customize your app metadata, as that is read prior to this hook being called (during Electron Packager's afterCopy hooks).