[Re.pack v5 + MF2] Cannot load bundle from local path

[longb1997]

Describe the bug

Thank you for your support and appreciation of this amazing library!

In my case, I download the build folder from a self-hosted server to my local device and read its contents. First, the system downloads all files in the bundle folder. After saving them to the device's local storage, it initializes and calls registerRemotes with the entry point set to the local path of mf-manifest.json, which includes all the downloaded bundle folders.

But error showing up

Warning: Error: [ Federation Runtime ]: remoteEntryExports is undefined 
 {
  "name": "hostApp/miniApp",
  "alias": "miniApp",
  "entry": "https:noop:///mini.container.js.bundle",
  "shareScope": "default",
  "type": "global",
  "entryGlobalName": "miniApp",
  "version": "file:///Users/mobile/Library/Developer/CoreSimulator/Devices/E4676B6B-885A-47B6-B7D6-24034FD526D4/data/Containers/Data/Application/E53DB778-594B-4A0D-B2AA-2C3672DD5E9F/Library/Caches/miniapps/miniApp/0.0.1/ios/mf-manifest.json",
  "buildVersion": "0.0.1"
}

System Info

System:
  OS: macOS 15.2
  CPU: (10) arm64 Apple M4
  Memory: 115.44 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 20.18.3
    path: ~/.nvm/versions/node/v20.18.3/bin/node
  Yarn:
    version: 1.22.22
    path: ~/.nvm/versions/node/v20.18.3/bin/yarn
  npm:
    version: 10.8.2
    path: ~/.nvm/versions/node/v20.18.3/bin/npm
  Watchman:
    version: 2025.02.10.00
    path: /opt/homebrew/bin/watchman
Managers:
  CocoaPods:
    version: 1.16.2
    path: /Users/mobile/.rbenv/shims/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.2
      - iOS 18.2
      - macOS 15.2
      - tvOS 18.2
      - visionOS 2.2
      - watchOS 11.2
  Android SDK: Not Found
IDEs:
  Android Studio: 2024.3 AI-243.22562.218.2431.13114758
  Xcode:
    version: 16.2/16C5032a
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 11.0.26
    path: /usr/bin/javac
  Ruby:
    version: 3.1.2
    path: /Users/mobile/.rbenv/shims/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 15.0.1
    wanted: 15.0.1
  react:
    installed: 18.3.1
    wanted: 18.3.1
  react-native:
    installed: 0.76.9
    wanted: 0.76.9
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

Re.Pack Version

5.0.6

Reproduction

https://github.com/longb1997/repack-issue-load-local/tree/main

Steps to reproduce

I listed in README.MD in reproduce repository

[jbroma]

Hi @longb1997,

from the repository you've added I can see that you're trying to register the remote dynamically and then prefetch the resources to local filesystem using RNFetchBlob and then load that remote from local - reading from device filesystem like that is not supported - registerRemotes is a MF API that only supports http protocol atm.

In 5.1.0 of Re.Pack we've added support for prefetchRemote through Module Federation which will take care of your use-case, without having to manually handle the filesystem like that - it will be done under the hood by ScriptManager.

Please try upgrading to Re.Pack 5.1.0, and then take a look here on how to use the prefetchRemote API here: #1136

[longb1997]

Hi @longb1997,

from the repository you've added I can see that you're trying to register the remote dynamically and then prefetch the resources to local filesystem using RNFetchBlob and then load that remote from local - reading from device filesystem like that is not supported - registerRemotes is a MF API that only supports http protocol atm.

In 5.1.0 of Re.Pack we've added support for prefetchRemote through Module Federation which will take care of your use-case, without having to manually handle the filesystem like that - it will be done under the hood by ScriptManager.

Please try upgrading to Re.Pack 5.1.0, and then take a look here on how to use the prefetchRemote API here: #1136

i will try, thank you so much

[decisionnguyen]

Hi @longb1997,

from the repository you've added I can see that you're trying to register the remote dynamically and then prefetch the resources to local filesystem using RNFetchBlob and then load that remote from local - reading from device filesystem like that is not supported - registerRemotes is a MF API that only supports http protocol atm.

In 5.1.0 of Re.Pack we've added support for prefetchRemote through Module Federation which will take care of your use-case, without having to manually handle the filesystem like that - it will be done under the hood by ScriptManager.

Please try upgrading to Re.Pack 5.1.0, and then take a look here on how to use the prefetchRemote API here: #1136

Hello @jbroma,
Thank you for your dedication.

In the previous version, I also downloaded it to the device's storage and then loaded it from there.
That made it easier for me to manage updates or revert changes if needed, and displaying loading or downloading states was also straightforward.
For example:
While using mini app v0.0.2, the host app could still silently download version v0.0.3 in the background, so that the next time the app is opened, it could directly use v0.0.3 without needing to show a downloading screen.

[jbroma]

Hi @longb1997,
from the repository you've added I can see that you're trying to register the remote dynamically and then prefetch the resources to local filesystem using RNFetchBlob and then load that remote from local - reading from device filesystem like that is not supported - registerRemotes is a MF API that only supports http protocol atm.
In 5.1.0 of Re.Pack we've added support for prefetchRemote through Module Federation which will take care of your use-case, without having to manually handle the filesystem like that - it will be done under the hood by ScriptManager.
Please try upgrading to Re.Pack 5.1.0, and then take a look here on how to use the prefetchRemote API here: #1136

Hello @jbroma, Thank you for your dedication.

In the previous version, I also downloaded it to the device's storage and then loaded it from there. That made it easier for me to manage updates or revert changes if needed, and displaying loading or downloading states was also straightforward. For example: While using mini app v0.0.2, the host app could still silently download version v0.0.3 in the background, so that the next time the app is opened, it could directly use v0.0.3 without needing to show a downloading screen.

you can achieve the same effect by using ScriptManager & doing invalidateScripts before the prefetchRemote and then on next app load, it will use the updated cache entry

[decisionnguyen]

you can achieve the same effect by using ScriptManager & doing invalidateScripts before the prefetchRemote and then on next app load, it will use the updated cache entry

Thank you to much, @jbroma
I will try this

[longb1997]

Hi @longb1997,
from the repository you've added I can see that you're trying to register the remote dynamically and then prefetch the resources to local filesystem using RNFetchBlob and then load that remote from local - reading from device filesystem like that is not supported - registerRemotes is a MF API that only supports http protocol atm.
In 5.1.0 of Re.Pack we've added support for prefetchRemote through Module Federation which will take care of your use-case, without having to manually handle the filesystem like that - it will be done under the hood by ScriptManager.
Please try upgrading to Re.Pack 5.1.0, and then take a look here on how to use the prefetchRemote API here: #1136

Hello @jbroma, Thank you for your dedication.
In the previous version, I also downloaded it to the device's storage and then loaded it from there. That made it easier for me to manage updates or revert changes if needed, and displaying loading or downloading states was also straightforward. For example: While using mini app v0.0.2, the host app could still silently download version v0.0.3 in the background, so that the next time the app is opened, it could directly use v0.0.3 without needing to show a downloading screen.

you can achieve the same effect by using ScriptManager & doing invalidateScripts before the prefetchRemote and then on next app load, it will use the updated cache entry

Thanks @jbroma, i have one more question.
If I want to achieve that, should the process be: init → registerRemotes → preloadRemotes?

[jbroma]

Thanks @jbroma, i have one more question. If I want to achieve that, should the process be: init → registerRemotes → preloadRemotes?

preloadRemotes can be used without the other two if you use the build plugin with remotes declared there.

registerRemotes can be used without init if you want to add a new remote dynamically in runtime

runtime MF with init allows you to declare remotes with it, later on you can use registerRemotes for new ones

[longb1997]

Thanks @jbroma, i have one more question. If I want to achieve that, should the process be: init → registerRemotes → preloadRemotes?

preloadRemotes can be used without the other two if you use the build plugin with remotes declared there.

registerRemotes can be used without init if you want to add a new remote dynamically in runtime

runtime MF with init allows you to declare remotes with it, later on you can use registerRemotes for new ones

I was reviewing #1136, but I couldn’t find where to set the entry files. How does preloadRemotes know where the bundle files are stored after being downloaded?

[jbroma]

Thanks @jbroma, i have one more question. If I want to achieve that, should the process be: init → registerRemotes → preloadRemotes?

preloadRemotes can be used without the other two if you use the build plugin with remotes declared there.
registerRemotes can be used without init if you want to add a new remote dynamically in runtime
runtime MF with init allows you to declare remotes with it, later on you can use registerRemotes for new ones

I was reviewing #1136, but I couldn’t find where to set the entry files. How does preloadRemotes know where the bundle files are stored after being downloaded?

It's handled by ScriptManager and it's cache - something that has been in Re.Pack for a long time

Basically, we create an ID out of remote name + chunk name and look it up on the filesystem

[longb1997]

Thanks @jbroma, i have one more question. If I want to achieve that, should the process be: init → registerRemotes → preloadRemotes?

preloadRemotes can be used without the other two if you use the build plugin with remotes declared there.
registerRemotes can be used without init if you want to add a new remote dynamically in runtime
runtime MF with init allows you to declare remotes with it, later on you can use registerRemotes for new ones

I was reviewing #1136, but I couldn’t find where to set the entry files. How does preloadRemotes know where the bundle files are stored after being downloaded?

It's handled by ScriptManager and it's cache - something that has been in Re.Pack for a long time

Basically, we create an ID out of remote name + chunk name and look it up on the filesystem

Thanks for your reply. In my case, I still need to download the bundle to the filesystem first and then process it, as we have specific cases to handle. For example, we need to manage specific versions for certain user groups.

Is there any way I can use the filesystem for preloadRemotes?

[jbroma]

The bundles are fetched, loaded and evaluated on the native side so it's not possible to process it after fetching but before loading. We would have to rework the native side to be more granular and orchestrate everything from JS so you could tap into individual stages of this process.

It's doable but it's definitely not on our roadmap since this is a very custom use-case.

[longb1997]

The bundles are fetched, loaded and evaluated on the native side so it's not possible to process it after fetching but before loading. We would have to rework the native side to be more granular and orchestrate everything from JS so you could tap into individual stages of this process.

It's doable but it's definitely not on our roadmap since this is a very custom use-case.

I really appreciate your help.
What I mean is that I haven’t found a way to configure the URL for repack to download from. I noticed it's defined in the remotes section of rspack.config.mjs, but what we need is a way to set it dynamically at runtime.

Do you have any way?