ezhangle / hermes-windows

Hermes is a small and lightweight JavaScript engine optimized for running React Native apps..

Hermes JS Engine for React Native Windows

Hermes is a JavaScript engine optimized for fast start up of React Native apps. It features ahead-of-time static optimization and compact bytecode. This repo is Microsoft’s fork of facebook/hermes and brings Hermes support to React Native Windows.

The following commands should get you going in a Windows Command Prompt:

mkdir hermes-windows-workingdir
cd hermes-windows-workingdir
git -c core.autocrlf=false clone https://github.com/microsoft/hermes-windows.git
python hermes-windows/utils/build/configure.py --build-system="Visual Studio 16 2019" --cmake-flags="-A x64" --distribute
cd build_release
MSBuild.exe ALL_BUILD.vcxproj /p:Configuration=Release

You will now be in a directory with the output of building Hermes into CLI tools. From here you can run a piece of JavaScript as follows:

echo 'use strict'; function hello() { print('Hello World'); } hello(); | .\bin\Release\hermes.exe

For more details on Hermes for Android, see here.

Contributing

The main purpose of this repository is to brings Hermes support to React Native Windows. We are grateful to the community for contributing bugfixes and improvements. Read below to learn how you can participate.

Code of Conduct

Both Microsoft and Facebook have adopted Codes of Conduct that we expect project participants to adhere to. Microsoft's Code of Conduct can be found here and Facebook's here. Please read through them so that you can understand what actions will and will not be tolerated.

Contributing Guide

Read our contributing guide to learn about our development process as well as how to propose bugfixes and improvements.

License

Hermes is MIT licensed.