Fix null values in CRUD entries being reported as strings

CHANGELOG.md

@@ -6,6 +6,7 @@
   to upload multiple transactions in a batch.
 * Fix modifying severity of the global Kermit logger
 * Add `PowerSync` tag for the logs
+* Fix `null` values in CRUD entries being reported as `"null"` strings.
 * [INTERNAL] Added helpers for Swift read and write lock exception handling.
 
 ## 1.4.0

core/src/commonIntegrationTest/kotlin/com/powersync/CrudTest.kt

@@ -134,6 +134,10 @@ class CrudTest {
                 )
             batch.crud[0].previousValues shouldBe null
 
+            batch.crud[1].opData shouldBe mapOf(
+                "a" to "te\"xt",
+                "b" to null,
+            )
             batch.crud[1].opData?.typed shouldBe
                 mapOf(
                     "a" to "te\"xt",

core/src/commonMain/kotlin/com/powersync/db/crud/SerializedRow.kt

@@ -4,6 +4,7 @@ import kotlinx.serialization.json.JsonElement
 import kotlinx.serialization.json.JsonNull
 import kotlinx.serialization.json.JsonObject
 import kotlinx.serialization.json.JsonPrimitive
+import kotlinx.serialization.json.contentOrNull
 import kotlinx.serialization.json.jsonPrimitive
 import kotlin.experimental.ExperimentalObjCRefinement
 import kotlin.native.HiddenFromObjC
@@ -47,11 +48,11 @@ internal class SerializedRow(
 
 private data class ToStringEntry(
     val inner: Map.Entry<String, JsonElement>,
-) : Map.Entry<String, String> {
+) : Map.Entry<String, String?> {
     override val key: String
         get() = inner.key
-    override val value: String
-        get() = inner.value.jsonPrimitive.content
+    override val value: String?
+        get() = inner.value.jsonPrimitive.contentOrNull
 }
 
 private class TypedRow(