forge-externals-plugin.js

    {
      __isElectronForgePlugin: true,
      async init() {
        //
      },
      getHook(hookName) {
        switch (hookName) {
          case "resolveForgeConfig":
            return this.resolveForgeConfig;
        }
      },
      async resolveForgeConfig(forgeConfig) {
        const externals = ["native-hello-world"];

        const modules = new Set(externals);

        for (const external of externals) {
          const moduleRoot = dirname(
            require.resolve(`${external}/package.json`)
          );

          const walker = new Walker(moduleRoot);
          (await walker.walkTree())
            .filter((dep) => dep.nativeModuleType === DepType.PROD)
            .map((dep) => dep.name)
            .forEach((name) => modules.add(name));
        }

        const existingFn = forgeConfig.packagerConfig.ignore;

        forgeConfig.packagerConfig.ignore = (file) => {
          const existingResult = existingFn(file);

          if (existingResult == false) {
            return false;
          }

          if (file === "/node_modules") {
            return false;
          }

          for (const module of modules) {
            if (file.startsWith(`/node_modules/${module}`)) {
              console.log(file, false);
              return false;
            }
          }

          return true;
        };
        return forgeConfig;
      },