RCTCxxModule incorrectly flagged as not exported module by RCTVerifyAllModulesExported

Is this a bug report?

Yes

Have you read the Bugs section of the Contributing to React Native Guide?

Yes

Environment

1. react-native -v: 0.45.1 / cli 2.0.1
2. node -v: v7.9.0
3. npm -v: 5.0.3
4. yarn --version (if you use Yarn): 0.24.6

Then, specify:

1. Target Platform: iOS
2. Development Operating System: macOS Sierra
3. Build tools: any supported Xcode version, any supported iOS version

Steps to Reproduce

1. Execute react-native init testproject
2. Open the Xcode project and hit run

Expected Behavior

No warnings should be logged to the Xcode console since we have the default setup.

Actual Behavior

In the Xcode log there is a warning about the RCTCxxModule not being exported:

2017-07-03 11:09:47.963 [warn][tid:main][RCTBridge.m:114] Class RCTCxxModule was not exported. Did you forget to use RCT_EXPORT_MODULE()?
2017-07-03 11:09:47.963285+0200 testproject[467:119661] Class RCTCxxModule was not exported. Did you forget to use RCT_EXPORT_MODULE()?

Reproducible Demo

Any newly created React-Native project using the CxxBridge has this issue.

Possible solution

The RCTVerifyAllModulesExported function uses the objc_copyClassList which also reports the RCTCxxModule. This triggers the warning that this module is not exported, but since the RCTCxxModule is merely a base class that can be used by real module implementation this is a false positive.

A possible solution would be to make an exception in RCTVerifyAllModulesExported for the RCTCxxModule so it will not be checked and the warning will not be produced.

Note: The warning will disappear when you create a module that subclasses RCTCxxModule since there is a check in place for that scenario. As long as there is no subclass yet this warning will pop up.

[hobo214]

this issue puzzle me a lot. My project ran smoothly days before, however this issue happens today, and this issue appears in every project inited by react-native-cli without any modification .

[warrenronsiek]

I solved this by making sure that NSAppTrasnportSecurity key in my info.plist had the correct values:

<key>NSAppTransportSecurity</key>
<dict>
	<key>NSAllowsArbitraryLoads</key>
	<true/>
	<key>NSAllowsArbitraryLoadsInWebContent</key>
	<true/>
	<key>NSAllowsLocalNetworking</key>
	<true/>
	<key>NSExceptionDomains</key>
	<dict/>
</dict>