用于模拟器的自定义 Expo 开发客户端

Question

I had a specific question about installing a custom expo development client on a simulator, specifically an iOS simulator. I know that there is a way to install an expo build in a simulator (outlined here: https://docs.expo.dev/build-reference/simulators/ ), but this is just a build and not a development client, which are two very different things. The concept of an expo development client is outlined here: https://docs.expo.dev/development/introduction/ . That means there is no Fast Refresh available, and I cannot modify my app in real-time by changing my code. This is a really important feature for me because I need to make sure my app is compatible with all iPhone sizes, and I need to be able to see the changes quickly without having to make a build every single time. Does anyone know how to do this, or if this is currently even possible?

Answer 1

A more detailed explanation of the issue can be found here: https://expo.canny.io/feature-requests/p/custom-dev-clients-for-simulator

Essentially the issue that I had was I did not set up my eas.json file correctly. I needed to change the preview build profile in the eas.json file so that it contained these parameters: "developmentClient": true and "ios": { "simulator": true } I then built my project using the command eas build --profile preview . I then followed the steps of downloading the tar.gz file, extracting the .app file, dragging it into the simulator, and I was able to successfully open the app and connect it to Metro where I could then see live changes.

Answer 2

Like @Raamiz Abbasi said, you can set developmentClient and simulator to true in your eas.json however if you want to go further, you can also use expo-dev-client to create a "custom expo go app" which is basically a customized expo go which you can publish updates to with the eas-update .

Expo Go and this new "development client" are both clients which serve the purpose of displaying your JS bundles. But, with the expo-dev-client you can do cool things like add extra debug buttons into the menu, or run publishes (or eas updates in this case) which would automatically feed into the dev client.

The reasoning for doing this, besides adding extra debug stuff in the debug menu, would be to avoid the pain of only being able to expo publish a "release" build. Right now expo publish builds used with expo go cannot be debuggable.