This simplifies the process of loading custom fonts that are resources in an iOS Apple SPM Package (Swift Package Manager).

Font+Autoregistering.swift

import Foundation
import UIKit

public typealias FontNameExt = (name: String, ext: String)

public func autoRegisteringFont(_ fontNames: [FontNameExt], _ spmBundleName : String) throws {
  guard let spmBundle = Bundle(bundleName: spmBundleName) else {
    throw("Fail to find bundle(\(spmBundleName).bundle) in your app bundle.")
  }
  try fontURLs(for: fontNames, in: spmBundle).forEach { try registerFont(from: $0) }
}

extension Bundle {
  convenience init?(bundleName: String) {
    self.init(path: "\(Bundle.main.bundlePath)/\(bundleName).bundle")
  }
}

func fontURLs(for fontNames: [FontNameExt], in bundle: Bundle) -> [URL] {
  return fontNames.compactMap { police in
    bundle.url(forResource: police.name, withExtension: police.ext)
  }
}

func registerFont(from url: URL) throws {
  guard let fontDataProvider = CGDataProvider(url: url as CFURL) else {
    throw("Could not get reference to font data provider.")
  }
  guard let font = CGFont(fontDataProvider) else {
    throw("Could not get font from CoreGraphics.")
  }
  var error: Unmanaged<CFError>?
  guard CTFontManagerRegisterGraphicsFont(font, &error) else {
    throw("Error registering font: \(dump(error)!).")
  }
}

This code will allow you to load font in otf of ttf that are shared through a SPM ressources.

This code has to be in the SPM module that have the font as ressources. In order to load the font your need to call autoRegisteringFont once in the lifetime of your app. I advise to call it in the init of your app and that's it, this code load custom fonts from SPM without the need to declare them.

    let fontToRegister = [
      FontNameExt(name: "CustomFont-Bold", ext: "otf"),
      FontNameExt(name: "CustomFont-It", ext: "otf"),
      FontNameExt(name: "CustomFont-Regular", ext: "otf"),
    ]
    do { try autoRegisteringFont(fontToRegister, "Pikachu_pkmn") } catch { dump(error) }

Trust me, typealias is not a good thing to use when you work in a team,
Also no need to pass SPM's bundle name to get the bundle.

Take a look at my updated methods.

@mrugeshtank Thanks for the message but I have fonts in multiple modules and the loader is in its own module. I can't use "Bundle.module" but I have to specify it. I have to rework my code anyways so I will take inspiration from your gist and my constraint.

Thanks,

Didn't get that.
I'm using this in SPM and made public func to register fonts in SPM. Calling that public func method from app's didFinishLaunchingWithOptions and working like charm.
I think SPM is the module itself. Are you having multiple Modules in a single SPM?

Take a look at Access a Resource in Code

Yes 126 SPM modules that means 126 library targets all in the same Package.swift