Fix readTransaction throwing for connection pools

Author: simolus3

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 1.14.2
+
+* Fix `readTransaction` throwing. This issue was introduced in version 1.14.0.
+
 ## 1.14.1
 
 * [Internal] The GRDB integration uses high-level GRDB APIs to run statements.

Sources/PowerSync/CurrentVersion.swift

@@ -1,2 +1,2 @@
 // The current version of the PowerSync Swift SDK. This should be updated to the latest version in `CHANGELOG.md` when a new version is released.
-let libraryVersion = "1.14.1"
+let libraryVersion = "1.14.2"

Sources/PowerSync/Implementation/AsyncConnectionPool.swift

@@ -90,9 +90,6 @@ final class AsyncConnectionPool: SQLiteConnectionPoolProtocol {
 
         if isWriter {
             let _ = try context.execute(sql: "pragma journal_mode = WAL", parameters: [])
-        } else {
-            // This is mainly an additional safety element, we also open read connections SQLITE_READONLY.
-            let _ = try context.execute(sql: "pragma query_only = TRUE", parameters: [])
         }
 
         let _ = try context.execute(sql: "pragma journal_size_limit = \(6 * 1024 * 1024)", parameters: [])

Tests/PowerSyncTests/Implementation/DatabaseImplementationTests.swift

@@ -0,0 +1,26 @@
+import Foundation
+@testable import PowerSync
+import Testing
+
+struct DatabaseImplementationTests {
+    @Test func readTransaction() async throws {
+        // Regression test for https://github.com/powersync-ja/powersync-swift/issues/142.
+        let db = PowerSyncDatabase(
+            schema: Schema(),
+            dbFilename: "read-tx-regression-test",
+            logger: DefaultLogger()
+        )
+
+        let error = try await db.readTransaction { tx in
+            try tx.get(sql: "SELECT 1", parameters: [], mapper: { cursor in  })
+            
+            // Writing to the database in a read-only connection must fail.
+            let error = #expect(throws: PowerSyncError.self) {
+                try tx.execute(sql: "DELETE FROM ps_kv", parameters: [])
+            }
+            return try #require(error?.errorDescription)
+        }
+        try await db.close(deleteDatabase: true)
+        #expect(error.contains("attempt to write a readonly database") == true)
+    }
+}