Fix build error and runtime error after proguard enabled.

[tdzl2003]

Fix:

1. :app:packageRelease FAILED caused by proguard exception: java.io.IOException: Please correct the above warnings first.
2. Fix runtime exception

java.lang.ExceptionInInitializerError
at com.facebook.react.ReactInstanceManagerImpl.recreateReactContextInBackgroundFromBundleFile(ReactInstanceManagerImpl.java:308)

[facebook-github-bot]

By analyzing the blame information on this pull request, we identified @mkonicek to be a potential reviewer.

[mkonicek]

Thanks for the fix!

[mkonicek]

Can you try changing this to?

# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
native <methods>;
}

keep class gives 7.1MB APK, keepclasseswithmembernames 6.8MB.

[tdzl2003]

I tried but it didn't work. There's still errors:

E/dalvikvm( 1032): ERROR: couldn't find native method
E/dalvikvm( 1032): Requested: Lcom/facebook/react/bridge/ReadableNativeArray;.getType:(I)Lcom/facebook/react/bridge/ReadableType;

Maybe there's another problem. I'll take a look and give a update for this PR.

[tdzl2003]

I read the code decompiled from classes-proguard. All other methods is fine but getType is missing. I don't know why...

[tdzl2003]

-keepclassmembers class * {
native <methods>;
}

this work for me. We should not only keep their names, but also keep native methods self, otherwise it may be stripped if not used.

[mkonicek]

Does this work as noted in the docs (http://proguard.sourceforge.net/manual/examples.html#native)?

-keepclasseswithmembernames,includedescriptorclasses class * {
native <methods>;
}

[facebook-github-bot]

@tdzl2003 updated the pull request.

[tdzl2003]

Nope. getType() method is still stripped. -keepclassmembers,includedescriptorclasses would be better to prepare the future.

I think getType is stripped but other methods are kept because getType wasn't used in modules provided by MainReactPackage

[tdzl2003]

includedescriptorclasses has no effect now because all the classes used by native method have annotation DoNotStrip

[facebook-github-bot]

@tdzl2003 updated the pull request.

[mkonicek]

ok ok thanks for looking!

[mkonicek]

@facebook-github-bot shipit

[facebook-github-bot]

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