Remove unnecessary syntax sugar from DateConverter

push-message-provider-fcm/src/main/kotlin/ru/touchin/push/message/provider/fcm/converters/DateConverter.kt

@@ -1,4 +1,4 @@
-package ru.touchin.push.message.provider.fcm.configurations
+package ru.touchin.push.message.provider.fcm.converters
 
 import org.springframework.beans.factory.annotation.Qualifier
 import org.springframework.boot.context.properties.ConfigurationPropertiesBinding
@@ -14,8 +14,8 @@ class DateConverter(
     private val simpleDateFormat: SimpleDateFormat
 ) : Converter<String, Date> {
 
-    override fun convert(source: String?): Date? {
-        return source?.let(simpleDateFormat::parse)
+    override fun convert(source: String): Date {
+        return simpleDateFormat.parse(source)
     }
 
 }

push-message-provider-fcm/src/test/kotlin/ru/touchin/push/message/provider/fcm/PushMessageProviderFcmTestApplication.kt

@@ -4,16 +4,19 @@ import com.fasterxml.jackson.annotation.JsonAutoDetect
 import com.fasterxml.jackson.annotation.PropertyAccessor
 import com.fasterxml.jackson.databind.ObjectMapper
 import com.fasterxml.jackson.databind.SerializationFeature
+import com.google.firebase.FirebaseApp
 import org.springframework.beans.factory.annotation.Qualifier
 import org.springframework.boot.SpringBootConfiguration
 import org.springframework.boot.test.context.TestConfiguration
+import org.springframework.context.ApplicationListener
 import org.springframework.context.annotation.Bean
+import org.springframework.context.event.ContextRefreshedEvent
 import java.text.SimpleDateFormat
 
 @TestConfiguration
 @SpringBootConfiguration
 @EnablePushMessageProviderFcm
-class PushMessageProviderFcmTestApplication {
+class PushMessageProviderFcmTestApplication : ApplicationListener<ContextRefreshedEvent> {
 
     @Bean
     fun objectMapper(
@@ -28,4 +31,12 @@ class PushMessageProviderFcmTestApplication {
         }
     }
 
+    override fun onApplicationEvent(event: ContextRefreshedEvent) {
+        clearSingletonsOutsideContainer()
+    }
+
+    private fun clearSingletonsOutsideContainer() {
+        FirebaseApp.getApps().forEach(FirebaseApp::delete)
+    }
+
 }