Android Gradle auto version

README.md

Android projet auto-version update

This gradle snippet setup auto management of versionCode and versionName using tags found on your git repository.

• When building an apk from a commit tagged v1.4.2, then versionName will be v1.4.2
• When building an apk from a commit abcd123 which is the 3rd one after tag v1.5.7, then versionName will be v1.5.7-3-gabcd123
• versionCode is automatically handled given versionName value

How to bump up the version number?

Just add a tag in your git repository name like v1.4.2.

app.gradle

// ... ususal stuff

/**
 * Compute versionCode from a version name.
 *
 * Expected version format:
 * - v1.2.4
 * - v1.2.4-45
 * - v1.2.4-45-*
 *
 * Test regular expression at https://regex101.com/r/tJ3hE2/2
 *
 * @param version name
 * @return versionCode value as an integer
 */
def buildVersionCode(version) {
    def m = version =~ /^v([0-9]+)\.([0-9]+)\.([0-9]+)(?:-([0-9]+).*)?/
    assert m.matches()
    def major = m.group(1).toInteger()
    def minor = m.group(2).toInteger()
    def patch = m.group(3).toInteger()
    def nbCommits = m.group(4) == null ? 0 : m.group(4).toInteger()
    (major * 100000000) + (minor * 1000000) + (patch * 1000) + nbCommits
}

/*
 * Gets the version name from the latest Git tag.
 *
 * Assumes tags start with `v` followed with 3 numbers as in {major}.{minor}.{patch}.
 *
 * Returns the commit description provided by the `git describe --tag` command. I.E.: the 8th 
 * commit after tag `v1.3.0`, having hash `6648e7b8c89b2d0b7fcfaaff25ab40ab610eb2a7` will produce:
 *     `v1.3.0-8-g6648e7b`
 *
 * See https://git-scm.com/docs/git-describe#_examples
 */
def getVersionName = { ->
    def stdout = new ByteArrayOutputStream()
    exec {
        commandLine "git describe --tag --match v[0-9]*.*.*".tokenize(' ')
        standardOutput = stdout
    }
    return stdout.toString().trim()
}

android {
    // ...

    defaultConfig {
        // ...
        versionName = getVersionName()
        versionCode = buildVersionCode(versionName)
    }
    // ...
}

// ...