Android support. Phase I.

[simonracz]

Android support Phase I. (#96)

I tried to limit the scope to make a small PR. I failed in that. :)

Goals/achievements of this PR:

• Hook into React Native and monitor the internals.
  -- JS timers
  -- JS bridge
  -- UI thread
  -- UI BG thread
  -- Native Modules thread
  -- JS thread
• Set up Espresso IdlingResources for them.
• Implement React Native fast reloading.
• To NOT include RN as a dependency. Everything is implemented with reflection.
• Come up with how to integrate detox by the end user. Easy, one-liner solution.
• Async test runner. (Based on Rotem's idea)
• Keep the architecture similar to detox iOS.

Non-goals of the PR:

• JS -> Java invocation
• Mapping the JS test API -> Espresso API
• Wrapping up ADB
• Integrating Android into detox configuration, detox build, detox test
• Fully automated tests

I tested it manually in the following sample project detox-android-tester. I set up a websocket server and called hard-wired commands through it to the test runner.

I suggest to start at Detox.Java when checking this PR.

[rotemmiz]

This is an amazing step towards an Android version!
Following my correspondence with @simonracz , we're waiting for him to merge detox-android-tester with detox/test app.

[simonracz]

Hey Rotem,

The new commit contains the following:

• I've extended the detox/scripts/build.sh to build the detox aar files. (this must be triggered manually like this : ./scripts/build.sh noframework android)
• I've updated the detox/test/android project, it uses the built aar.
• I've added a helper script for the manual test. Please check out it's comments. detox/test/scripts/test_android.sh

[rotemmiz]

a few notes here for future use

[rotemmiz]

do we need to androidTestCompile espresso here? I think we should just androidTestCompile detox instead, and remove line 129.

[rotemmiz]

We may be able to use the same reflection library as we use for our internal reflection mechanism (a small wrapper on top of Apache ReflectionUtils)