[Expo] Update support for Exponent

[axemclion]

The latest versions of ExponentJS do not require us to install react-native from Exponent Repo. Looks like exponent just works with pre-existing React Native repo.

Can we update the extension to do that ?

[axemclion]

cc @dikaiosune and @brentvatne for comments on this

[vladimir-kotikov]

@axemclion, just looked at this and it seems that CRNA-made projects works just fine with exp which probably means that we could get rid of this step for apps that were created using CRNA. I think we can detect this by looking for app.json w/ expo section at the root of the project.

The only thing that confuses me in this case is that exp prints a warning about version of react native

Warning: Not using the Expo fork of react-native. See https://docs.expo.io/.

and I'm not sure yet how much this warning is severe.

However, it seems that latest Expo (in particular I was using exp) is still requires (maybe this is not a strong requirement though) its own version of react-native:

  "dependencies": {
    "@expo/ex-navigation": "~2.9.2",
    "@expo/samples": "~1.0.3",
    "expo": "^15.0.2",
    "react": "~15.4.0",
    "react-native": "https://github.com/exponent/react-native/archive/sdk-15.0.0.tar.gz"
  },

[axemclion]

@vladimir-kotikov I think the best way to understand this would be to get on the Expo slack adn talk to @dikaiosune

[anp]

Hey! We can definitely chat on slack, but the basic rundown is:

Expo has a fork of RN where we sometimes land fixes to JS before they're available in a stable release. We maintain compatibility with the npm version of React Native for CRNA, but when you're running in exp or XDE, we warn you since you may not have all of the appropriate bugfixes. That said, as long as the sdkVersion flag is set to a compatible ABI for your RN install, things should just work.

AFAIK the only case where we require use of our fork is for apps using ExpoKit, because we bundle some native code in the npm package which our tools expect to configure as part of the Xcode/Android Studio builds.

[vladimir-kotikov]

@dikaiosune Cool! Thanks for clarification! Hope you wouldn't mind if I bother you in Slack if I have additional questions.

@panarasi, given what Adam says that should be pretty easy to get rid of that step - I'm going to prototype and test "debugging in Expo" scenario more thoroughly w/ both Expo and CRNA apps to see whether it's safe. Also I think there is currently some issues that actually break debugging scenario for CRNA apps but that's another issue - I'll investigate and file a separate ticket.

[rdickert]

It appears expo support is broken if you are using a current version for your app. When I try to run the debugger, I get warnings about invalid exp.json keys that are currently supported (like privacy and icon). I also get Warning: Installed version 0.40.0 of 'react-native' does not satify required version git+https://github.com/exponentjs/react-native#sdk-13.0.0\n\n

The debugger output ends with "Error starting tunnel: Error: {\"status_code\":400,\"msg\":\"failed to deserialize request parameter\",\"details\":{\"err\":{\"Type\":{}}}}" {"status_code":400,"msg":"failed to deserialize request parameter","details":{"err":{"Type":{}}}} and the debug console output is

[vscode-react-native] Starting Exponent Packager.
[Error] "Could not debug. An error ocurred while handling message: START_EXPONENT_PACKAGER"

I can submit a new issue if you think this is a separate bug, but I'm assuming this might be resolved with the updates planned.

[axemclion]

cc @vladimir-kotikov

[vladimir-kotikov]

Yeah, we have alredy tagged version 0.3.2 to be released that should fix all known problems w/ Expo support.

@axemclion, could you please help w/ publishing it?

[panarasi]

@vladimir-kotikov Just published the new version. Can you create a GitHub milestone and mark the issues as fixed ?

[vladimir-kotikov]

@panarasi, sure. Here it is: https://github.com/Microsoft/vscode-react-native/milestone/8?closed=1 and here is the release page: https://github.com/Microsoft/vscode-react-native/releases/tag/0.3.2