Slow compile times with react-native iOS app

Question

I am currently working on a react-native iOS app. While developing I noticed that the compile times for the app are really slow. I got a CI hooked up which roughly does the following:

• clean git checkout of the applications workspace
• run unit tests
• run UI tests build the app

Since this is a clean checkout the app always recompiles all of the react static libraries which come with the React.xcodeproj like libyoga.a, libReact.a, etc. This means that a clean CI build roughly takes ~8min only to build all of the react dependencies (~4min * 2 because the UI test target rebuilds React again).

I wondered whether it would be possible to speed up the compile times. I came up with the following idea but need your advice to tell me if it would work or if I am on the wrong track.

• Compile all static libraries for iphoneos and iphonesimulator
• Put them together in a single file via lipo
• Move them to a folder
• Put that folder into version control
• Link the libraries in that folder into the Xcode project

This way it would only be necessary to build a new set of static libraries if I update the react-native version in the package.json, right ?

Another idea which came to my mind is to build a dynamic framework of react-native. The framework could be build only once and then added to the application via carthage or manually. The dynamic framework would link all the react static libraries and add the correct headers to the header search paths.

Does anyone can give me a hint if this could work or has an idea how to improve the build architecture in order to speed up the compile time ?

Answer 1

Check these two checkbox 1 Show environment variables in build log 2 Run script only when installing

but when you run first time then uncheck it because this load script for first time otherwise you can not open get loading script in packager.