Increment versionCode task

versionCode.gradle

task('incrementVersionCode') << {
    def versionCode = Integer.parseInt(VERSION_CODE) + 1
    ant.propertyfile(file: "../gradle.properties") {
        entry(key: "VERSION_CODE", value: versionCode)
    }
}

tasks.whenTaskAdded { task ->
    if (task.name == 'assembleRelease') {
        task.dependsOn 'incrementVersionCode'
    }
}

In my case, I just placed the task at the bottom of the build.gradle file.

build.gradle

...

android {
    ...

    defaultConfig {
        ...
        versionCode Integer.parseInt(VERSION_CODE)
        ...
    }

    ...
}

...

task('incrementVersionCode') << {
    def versionCode = Integer.parseInt(VERSION_CODE) + 1
    ant.propertyfile(file: "../gradle.properties") {
        entry(key: "VERSION_CODE", value: versionCode)
    }
}

gradle.properties

...
VERSION_CODE=1 # this will get updated

Fastfile

...

gradle(
  task: "incrementVersionCode",
  project_dir: "android/"
)

git_commit(
  path: "android/gradle.properties",
  message: "Version Bump"
)
...

---

Thanks all!

Update: July 2019

">>" is deprecated and removed and the following syntax is favored for versionCode.gradle:

1. Create a new file called versionCode.gradle in android/app with the code below

task('incrementVersionCode') {
    description= "Increments Version Code"
    doLast {
        def versionCode = Integer.parseInt(VERSION_CODE) + 1
        ant.propertyfile(file: "../gradle.properties") {
            entry(key: "VERSION_CODE", value: versionCode)
        }
    }
}

2. Open android/app/build.gradle and add the following line: apply from: './versionCode.gradle'

Replace the versionCode line under default config in your app's build.gradle with:

    defaultConfig {
        ...
        versionCode 1  # Replace with versionCode Integer.parseInt(VERSION_CODE)
        ...
    }

3. Add VERSION_CODE=1 to your gradle.properties file.
4. Build