Last couple of months in my free time I was working on a small Android app by learning react native. This is my first experience of developing apps for mobiles.

When I started one thing I wanted to set up in the initial stage itself was the different application id for debug and production apks. This will help me have both builds installed at the same time. Also, it will make sure the even while development or testing, I can still use the production version on my phone.

Along with application id, I want different titles for apps to differentiate those apps on Home. The debug version will have title Reminder β and production will have Reminder (without β).

Setting application id

First, we can look into setting application id. The application id for debug will include <app name>-debug.

In the android/app/build.gradle there will be release config inside the buildTypes

/** android/app/build.gradle **/
android {
  /** other configs **/

  buildTypes {
    release {
      externalNativeBuild {
        cmake {
          arguments "-DANDROID_PACKAGE_NAME=${android.defaultConfig.applicationId}"
        }
      }
      minifyEnabled enableProguardInReleaseBuilds
      proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
    }
  }
}

We need to add debug config along with release with custom applicationIdSuffix & versionNameSuffix. Then append the versionNameSuffix to the package name argument.

The sample updated config is given below.

/** android/app/build.gradle **/
android {
  /** other configs **/

  buildTypes {
    release {
      externalNativeBuild {
        cmake {
          arguments "-DANDROID_PACKAGE_NAME=${android.defaultConfig.applicationId}"
        }
      }
      minifyEnabled enableProguardInReleaseBuilds
      proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
    }
+   debug {
+     applicationIdSuffix '.debug'
+     versionNameSuffix "-debug"
+     externalNativeBuild {
+       cmake {
+         arguments "-DANDROID_PACKAGE_NAME=${android.defaultConfig.applicationId}${applicationIdSuffix}"
+       }
+     }
+   }
  }
}

Setting title

To set the different titles for debug and production, we need to update the values in string.xml. For production, the title will be picked from main/res/values/string.xml

<resources>
    <string name="app_name">Reminder</string>
</resources>

and for debug the title will be picked from debug/res/values/string.xml

<resources>
    <string name="app_name">Reminder β</string>
</resources>