1 files changed, 115 insertions, 0 deletions
diff --git a/buildSrc/src/main/java/VersioningPlugin.kt b/buildSrc/src/main/java/VersioningPlugin.kt
new file mode 100644
index 00000000..7ff9709f
--- /dev/null
+++ b/buildSrc/src/main/java/VersioningPlugin.kt
@@ -0,0 +1,115 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+
+import com.android.build.gradle.internal.plugins.AppPlugin
+import com.github.zafarkhaja.semver.Version
+import java.io.OutputStream
+import java.util.Properties
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+
+private const val VERSIONING_PROP_FILE = "version.properties"
+private const val VERSIONING_PROP_VERSION_NAME = "versioning-plugin.versionName"
+private const val VERSIONING_PROP_VERSION_CODE = "versioning-plugin.versionCode"
+private const val VERSIONING_PROP_COMMENT = """
+This file was automatically generated by 'versioning-plugin'. DO NOT EDIT MANUALLY.
+"""
+
+/**
+ * A Gradle [Plugin] that takes a [Project] with the [AppPlugin] applied and dynamically sets the
+ * versionCode and versionName properties based on values read from a [VERSIONING_PROP_FILE] file in
+ * the [Project.getBuildDir] directory. It also adds Gradle tasks to bump the major, minor, and patch
+ * versions along with one to prepare the next snapshot.
+ */
+@Suppress(
+    "UnstableApiUsage",
+    "NAME_SHADOWING"
+)
+class VersioningPlugin : Plugin<Project> {
+
+    /**
+     * Generate the Android 'versionCode' property
+     */
+    private fun Version.androidCode(): Int {
+        return majorVersion * 1_00_00 +
+            minorVersion * 1_00 +
+            patchVersion
+    }
+
+    /**
+     * Write an Android-specific variant of [this] to [stream]
+     */
+    private fun Version.writeForAndroid(stream: OutputStream) {
+        val newVersionCode = androidCode()
+        val props = Properties()
+        props.setProperty(VERSIONING_PROP_VERSION_CODE, "$newVersionCode")
+        props.setProperty(VERSIONING_PROP_VERSION_NAME, toString())
+        props.store(stream, VERSIONING_PROP_COMMENT)
+    }
+
+    /**
+     * Returns the same [Version], but with build metadata stripped.
+     */
+    private fun Version.clearPreRelease(): Version {
+        return Version.forIntegers(majorVersion, minorVersion, patchVersion)
+    }
+
+    override fun apply(project: Project) {
+        with(project) {
+            val appPlugin = requireNotNull(plugins.findPlugin(AppPlugin::class.java)) {
+                "Plugin 'com.android.application' must be applied to use this plugin"
+            }
+            val propFile = layout.projectDirectory.file(VERSIONING_PROP_FILE)
+            require(propFile.asFile.exists()) {
+                "A 'version.properties' file must exist in the project subdirectory to use this plugin"
+            }
+            val contents = providers.fileContents(propFile).asText.forUseAtConfigurationTime()
+            val versionProps = Properties().also { it.load(contents.get().byteInputStream()) }
+            val versionName = requireNotNull(versionProps.getProperty(VERSIONING_PROP_VERSION_NAME)) {
+                "version.properties must contain a '$VERSIONING_PROP_VERSION_NAME' property"
+            }
+            val versionCode = requireNotNull(versionProps.getProperty(VERSIONING_PROP_VERSION_CODE).toInt()) {
+                "version.properties must contain a '$VERSIONING_PROP_VERSION_CODE' property"
+            }
+            appPlugin.extension.defaultConfig.versionName = versionName
+            appPlugin.extension.defaultConfig.versionCode = versionCode
+            afterEvaluate {
+                val version = Version.valueOf(versionName)
+                tasks.register("clearPreRelease") {
+                    doLast {
+                        version.clearPreRelease()
+                            .writeForAndroid(propFile.asFile.outputStream())
+                    }
+                }
+                tasks.register("bumpMajor") {
+                    doLast {
+                        version.incrementMajorVersion()
+                            .writeForAndroid(propFile.asFile.outputStream())
+                    }
+                }
+                tasks.register("bumpMinor") {
+                    doLast {
+                        version.incrementMinorVersion()
+                            .writeForAndroid(propFile.asFile.outputStream())
+                    }
+                }
+                tasks.register("bumpPatch") {
+                    doLast {
+                        version.incrementPatchVersion()
+                            .writeForAndroid(propFile.asFile.outputStream())
+                    }
+                }
+                tasks.register("bumpSnapshot") {
+                    doLast {
+                        version.incrementMinorVersion()
+                            .setPreReleaseVersion("SNAPSHOT")
+                            .writeForAndroid(propFile.asFile.outputStream())
+                    }
+                }
+            }
+        }
+    }
+}