chore: kotlin null handling

Author: MichaelVerdon

packages/firebase_database/firebase_database/android/src/main/kotlin/io/flutter/plugins/firebase/database/EventsProxy.kt

@@ -22,8 +22,8 @@ abstract class EventsProxy @JvmOverloads constructor(
     fun buildAdditionalParams(
         @NonNull eventType: String,
         @Nullable previousChildName: String?
-    ): Map<String, Any> {
-        val params = mutableMapOf<String, Any>()
+    ): Map<String, Any?> {
+        val params = mutableMapOf<String, Any?>()
         params[Constants.EVENT_TYPE] = eventType
 
         if (previousChildName != null) {

packages/firebase_database/firebase_database/android/src/main/kotlin/io/flutter/plugins/firebase/database/FirebaseDatabasePlugin.kt

@@ -254,8 +254,8 @@ class FirebaseDatabasePlugin : FlutterFirebasePlugin, FlutterPlugin, MethodCallH
         return taskCompletionSource.task
     }
 
-    private fun runTransaction(arguments: Map<String, Any>): Task<Map<String, Any>> {
-        val taskCompletionSource = TaskCompletionSource<Map<String, Any>>()
+    private fun runTransaction(arguments: Map<String, Any>): Task<Map<String, Any?>> {
+        val taskCompletionSource = TaskCompletionSource<Map<String, Any?>>()
 
         cachedThreadPool.execute {
             try {
@@ -276,8 +276,8 @@ class FirebaseDatabasePlugin : FlutterFirebasePlugin, FlutterPlugin, MethodCallH
         return taskCompletionSource.task
     }
 
-    private fun queryGet(arguments: Map<String, Any>): Task<Map<String, Any>> {
-        val taskCompletionSource = TaskCompletionSource<Map<String, Any>>()
+    private fun queryGet(arguments: Map<String, Any>): Task<Map<String, Any?>> {
+        val taskCompletionSource = TaskCompletionSource<Map<String, Any?>>()
 
         cachedThreadPool.execute {
             try {

packages/firebase_database/firebase_database/android/src/main/kotlin/io/flutter/plugins/firebase/database/FlutterDataSnapshotPayload.kt

@@ -10,10 +10,10 @@ import com.google.firebase.database.DataSnapshot
 import java.util.*
 
 class FlutterDataSnapshotPayload(snapshot: DataSnapshot) {
-    private var payloadMap: MutableMap<String, Any> = mutableMapOf()
+    private var payloadMap: MutableMap<String, Any?> = mutableMapOf()
 
     init {
-        val snapshotMap = mutableMapOf<String, Any>()
+        val snapshotMap = mutableMapOf<String, Any?>()
 
         snapshotMap[Constants.KEY] = snapshot.key ?: ""
         snapshotMap[Constants.VALUE] = snapshot.value
@@ -36,15 +36,15 @@ class FlutterDataSnapshotPayload(snapshot: DataSnapshot) {
         payloadMap[Constants.SNAPSHOT] = snapshotMap
     }
 
-    fun withAdditionalParams(params: Map<String, Any>): FlutterDataSnapshotPayload {
+    fun withAdditionalParams(params: Map<String, Any?>): FlutterDataSnapshotPayload {
         val prevPayloadMap = payloadMap
         payloadMap = mutableMapOf()
         payloadMap.putAll(prevPayloadMap)
         payloadMap.putAll(params)
         return this
     }
 
-    fun toMap(): Map<String, Any> {
+    fun toMap(): Map<String, Any?> {
         return payloadMap
     }
 }

packages/firebase_database/firebase_database/android/src/main/kotlin/io/flutter/plugins/firebase/database/TransactionHandler.kt

@@ -24,16 +24,16 @@ class TransactionHandler @JvmOverloads constructor(
     private val transactionKey: Int
 ) : Handler {
 
-    private val transactionCompletionSource = TaskCompletionSource<Map<String, Any>>()
+    private val transactionCompletionSource = TaskCompletionSource<Map<String, Any?>>()
 
-    fun getTask(): Task<Map<String, Any>> {
+    fun getTask(): Task<Map<String, Any?>> {
         return transactionCompletionSource.task
     }
 
     @NonNull
     override fun doTransaction(@NonNull currentData: MutableData): Transaction.Result {
-        val snapshotMap = mutableMapOf<String, Any>()
-        val transactionArgs = mutableMapOf<String, Any>()
+        val snapshotMap = mutableMapOf<String, Any?>()
+        val transactionArgs = mutableMapOf<String, Any?>()
 
         snapshotMap[Constants.KEY] = currentData.key ?: ""
         snapshotMap[Constants.VALUE] = currentData.value
@@ -74,7 +74,7 @@ class TransactionHandler @JvmOverloads constructor(
             }
             currentData != null -> {
                 val payload = FlutterDataSnapshotPayload(currentData)
-                val additionalParams = mutableMapOf<String, Any>()
+                val additionalParams = mutableMapOf<String, Any?>()
                 additionalParams[Constants.COMMITTED] = committed
                 transactionCompletionSource.setResult(payload.withAdditionalParams(additionalParams).toMap())
             }