getUpdateMetadata gives false package with DEBUG build

[adbl]

Running a DEBUG build in simulator (and probably on device too), using this in AppDelegate.m:

 #ifdef DEBUG
  jsCodeLocation = [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index.ios" fallbackResource:nil];
#else
  jsCodeLocation = [CodePush bundleURL];
#endif

which should make it impossible that a Code Push update gets loaded?

1. The first run this works as expected, codePush.getUpdateMetadata() returns null.
2. During this run, Code Push detected, downloaded and installed an update.
3. During next launch, codePush.getUpdateMetadata() now gives the package that was downloaded, however it clearly isn't running. It's running the dev bundle from packager.

This had me extremely confused until I figured out that it wasn't actually running the update. It seems like getUpdateMetadata doesn't understand that an "installed" package may not be running, due to the CodePush bundle loader was not in use.

• react-native-code-push version: 1.16.1-beta
• react-native version: 0.36.1
• iOS/Android/Windows version: iOS 10.2
• Does this reproduce on a debug build or release build? deug
• Does this reproduce on a simulator, or only on a physical device? Simulator (both?)

[sergey-akhalkov]

@adbl - hi!
getUpdateMetadata method returns info about latest installed package and supposes that local js code is in use, I don't sure if its behavior should be changed to determine js code location...
To make it easier to understand what js code location is in use we could output its location using this:

...
const { SourceCode } = require('NativeModules');
...
<Text style={styles.messages}>{SourceCode.scriptURL}</Text>
...

Depending on jsCodeLocation variable value it prints different paths:

1. jsCodeLocation = [CodePush bundleURL];
2. jsCodeLocation = [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index.ios" fallbackResource:nil];
   

As for debugging:

#ifdef DEBUG
  jsCodeLocation = [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index.ios" fallbackResource:nil];
#else
  jsCodeLocation = [CodePush bundleURL]; 

#endif

Regarding to this code lines dev bundle is used on each app start. To make it possible to use local js code in debug mode we should done following:

1. Replace jsCodeLocation = [[RCTBundleURLProvider sharedSettings] jsBundleURLForBundleRoot:@"index.ios" fallbackResource:nil]; with jsCodeLocation = [CodePush bundleURL];.
2. Force the JS bundle to be generated in simulator builds by removing the if block that echoes "Skipping bundling for Simulator platform" in the "node_modules/react-native/packager/react-native-xcode.sh" file.

[adbl]

I don't know if it should be changed either, but it did cause confusion for me at least. From that perspective it would be nicer if CodePush could detect that the bundle isn't actually RUNNING (which is the default query to getMetaData), because it is in fact not running.

If you don't think it should change then I can workaround this by either checking the source url as you suggest and match against localhost or I can simply just check for __DEV__. But I prefer to now have to think about __DEV__ nor js code location. I also want the option to use codePush in a development built at a later time for certain kinds of testing and not have to think about any code that make assumptions about __DEV__ + codePush.

Maybe then, codePush could export a new function which let's me know whether React is running code loaded by it?

[adbl]

Actually, given the documentation for getUpdateMetadata:

The updateState parameter is set to UpdateState.RUNNING, but the app isn't currently running a CodePush update. There may be a pending update, but the app hasn't been restarted yet in order to make it active.

This update could be described as UpdateState.PENDING, but that might also be confusing, since codePush cannot know if it will be loaded next time either. Maybe there could be an UpdateState.INSTALLED or UpdateState.INACTIVE with documentation describing the possible reasons for this update that is installed but still not running?

[sergey-akhalkov]

@Abdl, I've created #673 PR contains isUsingReactNativeBundle method. Please let me know if you have any questions or see any issues.

[adbl]

Nice @sergey-akhalkov!

Maybe we should also add a bit of documentation to getUpdateMetadata to describe the scenario I initially described which had me confused...?

[sergey-akhalkov]

@adbl, I've committed docs updates in #673

[panarasi]

I just closed #673 since I am not sure we need to add this method to Code Push. I think a better way would be to update the documentation to specify that only release mode is used.

@sergey-akhalkov is creating a new bug to update the documentation and will update the bug number here. I think we should close this issue once we have the bug for adding documentation.

[sergey-akhalkov]

@panarasi, done! The issue number is #682