feat: Adding support for providing a default properties file. (#7)

plugin/src/main/java/com/google/secrets_gradle_plugin/SecretsPlugin.kt

@@ -35,10 +35,18 @@ class SecretsPlugin : Plugin<Project> {
             SecretsPluginExtension::class.java
         )
         project.afterEvaluate {
+            val defaultProperties = extension.defaultPropertiesFileName?.let {
+                project.rootProject.loadPropertiesFile(it)
+            }
             val properties = project.rootProject.loadPropertiesFile(
                 extension.propertiesFileName
             )
             project.androidProject()?.applicationVariants?.all { variant ->
+                // Inject defaults first
+                defaultProperties?.let {
+                    variant.inject(it, extension.ignoreList)
+                }
+
                 variant.inject(properties, extension.ignoreList)
             }
         }

plugin/src/main/java/com/google/secrets_gradle_plugin/SecretsPluginExtension.kt

@@ -28,6 +28,11 @@ open class SecretsPluginExtension {
      */
     var ignoreList: MutableList<String> = defaultIgnoreList
 
+    /**
+     * The name of the properties file containing secrets' default values.
+     */
+    var defaultPropertiesFileName: String? = null
+
     companion object {
         const val defaultPropertiesFile = "local.properties"
         val defaultIgnoreList = mutableListOf("sdk.dir")

sample-app/build.gradle.kts

@@ -48,6 +48,7 @@ secrets {
     // Optionally specify a different file name containing your secrets.
     // The plugin defaults to "local.properties"
     propertiesFileName = "secrets.properties"
+    // defaultPropertiesFileName = "secrets.defaults.properties"
 
     // Add keys that the plugin should ignore from the properties file
     ignoreList.add("keyToIgnore")

sample-app/src/main/AndroidManifest.xml

@@ -27,7 +27,7 @@
         android:theme="@style/Theme.MyApplication">
         <meta-data
             android:name="com.google.android.geo.API_KEY"
-            android:value="gmpApiKey" />
+            android:value="${gmpApiKey}" />
         <activity
             android:name="com.google.secrets_gradle_plugin.sample.MainActivity"
             android:label="@string/app_name"

secrets.defaults.properties

@@ -0,0 +1,7 @@
+## Sample properties file containing application secrets.
+# This file is checked into version control for the sake of demonstrating sample contents.
+# In practice, your properties file that contains secrets *should not* be under version control.
+gmpApiKey=""
+keyToIgnore=""
+ignoreKey1=""
+ignoreKey2=""

settings.gradle.kts

@@ -16,7 +16,7 @@ include(":plugin", ":sample-app")
 
 pluginManagement {
     repositories {
-        gradlePluginPortal()
         maven(url = "./plugin/build/repository")
+        gradlePluginPortal()
     }
 }