more error handling

Author: Krzysztof Borowy

android/src/main/java/com/reactnativecommunity/asyncstorage/next/ArgumentHelpers.kt

@@ -6,14 +6,17 @@ import com.facebook.react.bridge.ReadableArray
 fun ReadableArray.toEntryList(): List<Entry> {
     val list = mutableListOf<Entry>()
     for (keyValue in this.toArrayList()) {
-        if (keyValue !is ArrayList<*>) {
+        if (keyValue !is ArrayList<*> || keyValue.size != 2) {
             throw AsyncStorageError.invalidKeyValueFormat()
         }
         val key = keyValue[0]
         val value = keyValue[1]
 
         if (key == null || key !is String) {
-            throw AsyncStorageError.keyIsNull()
+            when (key) {
+                null -> throw AsyncStorageError.keyIsNull()
+                !is String -> throw AsyncStorageError.keyNotString()
+            }
         }
 
         if (value !is String) {
@@ -26,7 +29,7 @@ fun ReadableArray.toEntryList(): List<Entry> {
 }
 
 fun ReadableArray.toKeyList(): List<String> {
-    val list = this.toArrayList().toList()
+    val list = this.toArrayList()
 
     for (item in list) {
         if (item !is String) {

android/src/main/java/com/reactnativecommunity/asyncstorage/next/ErrorHelpers.kt

@@ -23,14 +23,17 @@ internal class AsyncStorageError private constructor(val errorMessage: String) :
     Throwable(errorMessage) {
 
     companion object {
-        fun keyIsNull() = AsyncStorageError("Key cannot be null")
+        fun keyIsNull() = AsyncStorageError("Key cannot be null.")
 
-        fun invalidKeyValueFormat() =
-            AsyncStorageError("Invalid key-value format. Expected a list of [key, value] list.")
+        fun keyNotString() = AsyncStorageError("Provided key is not string. Only strings are supported as storage key.")
 
         fun valueNotString(key: String?): AsyncStorageError {
             val detail = if (key == null) "Provided value" else "Value for key \"$key\""
-            return AsyncStorageError("$detail is not of type String")
+            return AsyncStorageError("$detail is not a string. Only strings are supported as a value.")
         }
+
+        fun invalidKeyValueFormat() =
+            AsyncStorageError("Invalid key-value format. Expected a list of [key, value] list.")
+
     }
 }

android/src/main/java/com/reactnativecommunity/asyncstorage/next/StorageModule.kt

@@ -23,6 +23,7 @@ class StorageModule(reactContext: ReactContext) : ReactContextBaseJavaModule(),
     /**
      * Todo:
      *  - MultiMerge
+     *  - Documenting the migration, access from Brownfield and error handling
      */
 
     @ReactMethod

example/examples/Basic.js

@@ -44,21 +44,11 @@ function NextExample() {
   }
 
   async function crashKeyNull() {
-    await AsyncStorage.setItem(null, 435345);
+    await AsyncStorage.setItem(null, '435345');
   }
 
-  function unknownCrash() {
-    // very unlikely to happen, unless module used directly
-    return new Promise((res, rej) => {
-      RCTAsyncStorage.multiSet(['key', 'crash'], function(errors) {
-        if (errors) {
-          const message = Array.isArray(errors) ? errors[0].message : errors.message;
-          rej(new Error(message));
-        } else {
-          res();
-        }
-      });
-    });
+  async function crashKeyNotString() {
+    await AsyncStorage.setItem(432, '435345');
   }
 
   async function removeValue() {
@@ -88,8 +78,8 @@ function NextExample() {
       <Text style={{fontSize: 16, fontWeight: '700'}}>Crash scenarios</Text>
       <View style={{flexDirection: 'row', justifyContent: 'space-around'}}>
         <Button title="Key null" onPress={runWithCatch(crashKeyNull)}/>
+        <Button title="Key not string" onPress={runWithCatch(crashKeyNotString)}/>
         <Button title="Wrong value type" onPress={runWithCatch(crashValueType)}/>
-        <Button title="Other crash" onPress={runWithCatch(unknownCrash)}/>
       </View>
     </View>