TravisCI for Android & Arduino

A sample repository with a Travis Continuous Integration setup for an Arduino sketch and an Android application.

What?

This repository includes a sample TravisCI configuration for a system that includes an Android application and an Arduino sketch. After being triggered, it performs the following actions:

• Builds the Android application
• Runs the Android application's unit tests
• Runs the Android application's instrumented tests
• Builds the Arduino sketch(es)

Why?

Continuous Integration is good for you. It ensures the development team their newly introduced changes do not break the already existing functionality and do not introduce regressions. Furthermore, it potentially enables them to continuously deliver or deploy their software.

How?

When using the default TravisCI configuration, the CI job gets triggered whenever a new commit is pushed on any branch or a pull request is created.

It performs all actions defined in .travis.yml and if one of them fails it designates the entire build as unsuccessful. Each stage of the job lifecycle is rather excessively documented and explained, however especially the parts regarding the Android application are rather tricky and, sadly, tend to break upon the release of new API and SDK versions.

Compiling the Android app

The Android application demonstrates how to (not) store secret API keys in a public repository, by keeping gradle.properties out of the version control system. This means that if you just open the application with Android Studio it will fail to compile. To achieve that you need to create a copy of gradle.properties.no.git in the same directory and name it gradle.properties. Then you can insert in the newly created gradle.properties your secret API keys without having to version control them.

This approach, will also work on TravisCI which creates the gradle.properties file and sets the secret API credentials (if needed, e.g. for instrumented tests) via environment variables defined in settings. Please remember that if you need to make any version controlled changes to your gradle.properties, these need to be made in its version controlled copy, i.e. gradle.properties.no.git.