fix: capacitor readTransaction not allowed errors (#768)

Author: stevensJourney

.changeset/gorgeous-scissors-drive.md

@@ -0,0 +1,5 @@
+---
+'@powersync/common': patch
+---
+
+Fixed readTransaction method throwing "not allowed in read-only mode" errors

packages/capacitor/README.md

@@ -82,7 +82,7 @@ const db = new PowerSyncDatabase({
 
 - Encryption for native mobile platforms is not yet supported.
 - `PowerSyncDatabase.executeRaw` does not support results where multiple columns would have the same name in SQLite
-- `PowerSyncDatabase.execute` has limited support on Android. The SQLCipher Android driver exposes queries and executions as separate APIs, so there is no single method that handles both. While `PowerSyncDatabase.execute` accepts both, on Android we treat a statement as a query only when the SQL starts with `select` (case-insensitive).
+- `PowerSyncDatabase.execute` has limited support on Android. The SQLCipher Android driver exposes queries and executions as separate APIs, so there is no single method that handles both. While `PowerSyncDatabase.execute` accepts both, on Android we treat a statement as a query only when the SQL starts with `select` (case-insensitive). Queries such as `INSERT into customers (id, name) VALUES (uuid(), 'name') RETURNING *` do not work on Android.
 - Multiple tab support is not available for native Android and iOS targets. If you're not opening a second webview in your native app using something like `@jackobo/capacitor-webview`, you are unaffected by this.
 
 ## Examples

packages/capacitor/src/adapter/CapacitorSQLiteAdapter.ts

@@ -118,22 +118,31 @@ export class CapacitorSQLiteAdapter extends BaseObserver<DBAdapterListener> impl
   }
 
   protected generateLockContext(db: SQLiteDBConnection): LockContext {
+    const _query = async (query: string, params: any[] = []) => {
+      const result = await db.query(query, params);
+      const arrayResult = result.values ?? [];
+      return {
+        rowsAffected: 0,
+        rows: {
+          _array: arrayResult,
+          length: arrayResult.length,
+          item: (idx: number) => arrayResult[idx]
+        }
+      };
+    };
+
     const _execute = async (query: string, params: any[] = []): Promise<QueryResult> => {
       const platform = Capacitor.getPlatform();
+
+      if (db.getConnectionReadOnly()) {
+        return _query(query, params);
+      }
+
       if (platform == 'android') {
         // Android: use query for SELECT and executeSet for mutations
         // We cannot use `run` here for both cases.
         if (query.toLowerCase().trim().startsWith('select')) {
-          const result = await db.query(query, params);
-          const arrayResult = result.values ?? [];
-          return {
-            rowsAffected: 0,
-            rows: {
-              _array: arrayResult,
-              length: arrayResult.length,
-              item: (idx: number) => arrayResult[idx]
-            }
-          };
+          return _query(query, params);
         } else {
           const result = await db.executeSet([{ statement: query, values: params }], false);
           return {
@@ -166,24 +175,9 @@ export class CapacitorSQLiteAdapter extends BaseObserver<DBAdapterListener> impl
       ? (sql: string, params?: any[]) => monitorQuery(sql, () => _execute(sql, params))
       : _execute;
 
-    const _executeQuery = async (query: string, params?: any[]): Promise<QueryResult> => {
-      let result = await db.query(query, params);
-
-      let arrayResult = result.values ?? [];
-
-      return {
-        rowsAffected: 0,
-        rows: {
-          _array: arrayResult,
-          length: arrayResult.length,
-          item: (idx: number) => arrayResult[idx]
-        }
-      };
-    };
-
     const executeQuery = this.options.debugMode
-      ? (sql: string, params?: any[]) => monitorQuery(sql, () => _executeQuery(sql, params))
-      : _executeQuery;
+      ? (sql: string, params?: any[]) => monitorQuery(sql, () => _query(sql, params))
+      : _query;
 
     const getAll = async <T>(query: string, params?: any[]): Promise<T[]> => {
       const result = await executeQuery(query, params);