hack fix watch exceptions

Author: stevensJourney

Sources/PowerSync/Kotlin/KotlinPowerSyncDatabaseImpl.swift

@@ -183,6 +183,14 @@ final class KotlinPowerSyncDatabaseImpl: PowerSyncDatabaseProtocol {
                 Task {
                     do {
                         var mapperError: Error?
+                        // HACK!
+                        // SKIEE doesn't support custom exceptions in Flows
+                        // Exceptions which occur in the Flow itself cause runtime crashes.
+                        // The most probable crash would be the internal EXPLAIN statement.
+                        // This attempts to EXPLAIN the query before passing it to Kotlin
+                        // We could introduce an onChange API in Kotlin which we use to implement watches here.
+                        // This would prevent most issues with exceptions.
+                        _ = try await self.kotlinDatabase.get(sql: "EXPLAIN \(options.sql)", parameters: options.parameters, mapper: {_ in ""})
                         for try await values in try self.kotlinDatabase.watch(
                             sql: options.sql,
                             parameters: options.parameters,