added firebase messaging service late init for test supports (#17)

Author: oyakovlev

README.md

@@ -8,7 +8,7 @@ repositories {
 }
 
 // Append dependency
-implementation("com.icerockdev.service:fcm-push-service:2.1.1")
+implementation("com.icerockdev.service:fcm-push-service:2.1.2")
 ````
 
 ## Koin configure

fcm-push-service/build.gradle.kts

@@ -5,7 +5,7 @@ import kotlin.text.String
  */
 
 group = "com.icerockdev.service"
-version = "2.1.1"
+version = "2.1.2"
 
 plugins {
     id("org.jetbrains.kotlin.jvm")

fcm-push-service/src/main/kotlin/com/icerockdev/service/fcmpush/FCMConfig.kt

@@ -5,5 +5,6 @@
 package com.icerockdev.service.fcmpush
 
 data class FCMConfig(
-    val googleServiceAccountJson: String
+    val googleServiceAccountJson: String,
+    val lateInit: Boolean = false
 )

fcm-push-service/src/main/kotlin/com/icerockdev/service/fcmpush/PushService.kt

@@ -24,18 +24,21 @@ import org.slf4j.LoggerFactory
 class PushService(
     private val coroutineScope: CoroutineScope,
     private val pushRepository: IPushRepository,
-    config: FCMConfig
+    private val config: FCMConfig
 ) {
-    private val firebaseMessaging: FirebaseMessaging
+    private lateinit var firebaseMessaging: FirebaseMessaging
 
     init {
-        val options = FirebaseOptions.builder()
-            .setCredentials(GoogleCredentials.fromStream(config.googleServiceAccountJson.byteInputStream()))
-            .build()
-        firebaseMessaging = FirebaseMessaging.getInstance(FirebaseApp.initializeApp(options))
+        if (!config.lateInit) {
+            initFirebaseMessagingService()
+        }
     }
 
     fun sendAsync(payLoad: FCMPayLoad): Deferred<PushResult> {
+        if (config.lateInit) {
+            initFirebaseMessagingService()
+        }
+
         if (payLoad.tokenList.isEmpty()) {
             throw PushException("Unsupported empty token list")
         }
@@ -164,6 +167,17 @@ class PushService(
         )
     }
 
+    private fun initFirebaseMessagingService() {
+        if (this::firebaseMessaging.isInitialized) {
+            return
+        }
+
+        val options = FirebaseOptions.builder()
+            .setCredentials(GoogleCredentials.fromStream(config.googleServiceAccountJson.byteInputStream()))
+            .build()
+        firebaseMessaging = FirebaseMessaging.getInstance(FirebaseApp.initializeApp(options))
+    }
+
     private companion object {
         val logger: org.slf4j.Logger = LoggerFactory.getLogger(PushService::class.java)
         private const val FCM_TOKEN_CHUNK = 1000